Download Methods of forming a photovoltaic cell

HYPERION PATENTS UP FOR SALE, in the order listed in Docket # 2360
Bonding of thin lamina
US 20140048201 A1
ABSTRACT
Methods and apparatus are provided for bonding a thin lamina to a carrier. In some embodiments, a first side of
the lamina is separably contacted to a support plate. A first carrier having a first side with a layer of adhesive
material is contacted to the second side of the thin lamina. The lamina is fixed to the first carrier, where the fixing
includes a first application of heat and pressure to a portion of the lamina and the first carrier. The support plate
is removed, and a second application of heat and pressure are applied to the lamina and the first carrier. The
second application of heat and pressure promotes an adhesive bond between the lamina and the first carrier.
The second application of pressure comprises moving the lamina, the first carrier and a cover sheet between a
pair of rollers.
Silicon carbide lamina
WO 2014018462 A1
ABSTRACT
A method of fabricating an electronic device includes providing a silicon carbide or diamond-like carbon donor
body and implanting ions into a first surface of the donor body to define a cleave plane. After implanting, an
epitaxial layer is formed on the first surface, and a temporary carrier is coupled to the epitaxial layer. A lamina is
cleaved from the donor body at the cleave plane, and the temporary carrier is removed from the lamina. In some
embodiments a light emitting diode or a high electron mobility transistor is fabricated from the lamina and
epitaxial layer.
Method of forming a permanently supported lamina
WO 2013162834 A1
ABSTRACT
A method is described for forming a permanently supported thin lamina using decomposable adhesives between
a lamina and a temporary support element. The temporary support element may be bonded to a first surface of
the lamina. A permanent support element may be applied to a second surface of the lamina, and the temporary
support element debonded from the lamina by decomposing the adhesive.
Multi-layer metal support
US 8916954 B2
ABSTRACT
The invention provides a method of forming an electronic device from a lamina that has a coefficient of thermal
expansion that is matched or nearly matched to a constructed metal support. In some embodiments the method
comprises implanting the top surface of a donor body with an ion dosage to form a cleave plane followed by
exfoliating a lamina from the donor body. After exfoliating the lamina, a flexible metal support that has a
coefficient of thermal expansion with a value that is within 10% of the value of the coefficient of thermal
expansion of the lamina is constructed on the lamina. In some embodiments the coefficients of thermal
expansion of the metal support and the lamina are within 10% or within 5% of each other between the
temperatures of 100 and 600° C.
Multi-layer metal support
US 20130200497 A1
ABSTRACT
The invention provides a method of forming an electronic device from a lamina that has a coefficient of thermal
expansion that is matched or nearly matched to a constructed metal support. In some embodiments the method
comprises implanting the top surface of a donor body with an ion dosage to form a cleave plane followed by
exfoliating a lamina from the donor body. After exfoliating the lamina, a flexible metal support that has a
coefficient of thermal expansion with a value that is within 10% of the value of the coefficient of thermal
expansion of the lamina is constructed on the lamina. In some embodiments the coefficients of thermal
expansion of the metal support and the lamina are within 10% or within 5% of each other between the
temperatures of 500 and 1050° C.
Ion implant apparatus and a method of implanting ions
US 8633458 B2
ABSTRACT
Ion implant apparatus using a drum-type scan wheel holds wafers with a total cone angle less than 60°. A
collimated scanned beam of ions, for example H+, is directed along a final beam path which is at an angle of at
least 45° to the axis of rotation of the scan wheel. Ions are extracted from a source and accelerated along a
linear acceleration path to a high implant energy (more than 500 keV) before scanning or mass analysis. The
mass analyzer may be located near the axis of rotation and unwanted ions are directed to an annular beam
dump which may be mounted on the scan wheel.
Ion implant apparatus and a method of implanting ions
US 8759803 B2
ABSTRACT
Ion implant apparatus using a drum-type scan wheel holds wafers with a total cone angle less than 60°. A
collimated scanned beam of ions, for example H+, is directed along a final beam path which is at an angle of at
least 45° to the axis of rotation of the scan wheel. Ions are extracted from a source and accelerated along a
linear acceleration path to a high implant energy (more than 500 keV) before scanning or mass analysis. The
mass analyzer may be located near the axis of rotation and unwanted ions are directed to an annular beam
dump which may be mounted on the scan wheel.
Ion implant apparatus and method of ion implantation
US 8378317 B1
ABSTRACT
An apparatus and a method of ion implantation using a rotary scan assembly having an axis of rotation and a
periphery. A plurality of substrate holders is distributed about the periphery, and the substrate holders are
arranged to hold respective planar substrates. Each planar substrate has a respective geometric center on the
periphery. A beam line assembly provides a beam of ions for implantation in the planar substrates on the
holders. The beam line assembly is arranged to direct said beam along a final beam path.
Method and apparatus for forming a thin lamina
US 8268645 B2
ABSTRACT
A method for producing a lamina from a donor body includes implanting the donor body with an ion dosage and
heating the donor body to an implant temperature during implanting. The donor body is separably contacted with
a susceptor assembly, where the donor body and the susceptor assembly are in direct contact. A lamina is
exfoliated from the donor body by applying a thermal profile to the donor body. Implantation and exfoliation
conditions may be adjusted in order to maximize the defect-free area of the lamina.
Method and apparatus for forming a thin lamina
US 8435804 B2
ABSTRACT
A method for producing a lamina from a donor body includes implanting the donor body with an ion dosage and
separably contacting the donor body with a susceptor assembly, where the donor body and the susceptor
assembly are in direct contact. A lamina is exfoliated from the donor body, and a deforming force is applied to
the lamina or to the donor body to separate the lamina from the donor body.
Hydrogen implantation with reduced radiation
US 8101488 B1
ABSTRACT
Embodiments of the present invention provide for a system for accelerating hydrogen ions. A hydrogen
generator holding a supply of water is configured to generate a flow of hydrogen gas from the supply of water.
An ion source structure is configured to generate a plurality of hydrogen ions from the flow of hydrogen gas. An
accelerator tube is configured to accelerate the plurality of hydrogen ions. The supply of water has an isotopic
ratio of deuterium that is smaller than the isotopic ratio of deuterium in Vienna Standard Mean Ocean Water.
FIELD OF THE INVENTION
The invention relates generally to manufacturing processes utilizing accelerated particles, and more specifically
to a manufacturing process involving implantation of hydrogen ions into target materials.
A d.c. charged particle accelerator, a method of accelerating charged particles using d.c. voltages and a
high voltage power supply apparatus for use therewith
EP 2649863 A2 (text from WO2012078421A2)
ABSTRACT
A d. c. charged particle accelerator comprises accelerator electrodes separated by insulating spacers defining
acceleration gaps between adjacent pairs of electrodes. Individually regulated gap voltages are applied across
each adjacent pair of accelerator electrodes. In embodiments, the individually regulated gap voltages are
generated by electrically isolated alternators mounted on a common rotor shaft driven by an electric motor.
Alternating power outputs from the alternators provide inputs to individual regulated d. c. power supplies to
generate the gap voltages. The power supplies are electrically isolated and have outputs connected in series
across successive pairs of accelerator electrodes. The described embodiment enables an ion beam to be
accelerated to high energies and high beam currents, with good accelerator stability.
D.C. charged particle accelerator and a method of accelerating charged particles
US 8723452 B2
ABSTRACT
A d. c. charged particle accelerator comprises accelerator electrodes separated by insulating spacers defining
acceleration gaps between adjacent pairs of electrodes. Individually regulated gap voltages are applied across
each adjacent pair of accelerator electrodes. In an embodiment, direct connections are provided to gap
electrodes from the stage points of a multistage Cockcroft Walton type voltage multiplier circuit. The described
embodiment enables an ion beam to be accelerated to high energies and high beam currents, with good
accelerator stability.
Ion source and a method of generating an ion beam using an ion source
US 8324592 B2
ABSTRACT
Multiple control electrodes are provided asymmetrically within the plasma chamber of an ion source at respective
positions along the length of the plasma chamber. Biasing the control electrodes selectively can selectively
enhance the ion extraction current at adjacent positions along the length of the extraction slit. A method of
generating an ion beam is disclosed in which the strengths of the transverse electric fields at different locations
along the length of the plasma chamber are controlled to modify the ion beam linear current density profile along
the length of the slit. The method is used for controlling the uniformity of a ribbon beam.
Ion implantation apparatus
US 8426829 B2
ABSTRACT
An ion implanter has an implant wheel with a plurality of wafer carriers distributed about a periphery of the wheel.
Each wafer carrier has a heat sink for removing heat from a wafer on the carrier during the implant process by
thermal contact between the wafer and the heat sink. The wafer carriers have wafer retaining fences formed as
cylindrical rollers with axes in the respective wafer support planes of the wafer carriers. The cylindrical surfaces
of the rollers provide wafer abutment surfaces which can move transversely to the wafer support surfaces so that
no transverse loading is applied by the fences to wafer edges as the wafer is pushed against the heat sink by
centrifugal force. The wafer support surfaces comprise layers of elastomeric material and the movable abutment
surfaces of the fences allow even thermal coupling with the heat sink over the whole area of the wafer.
Method to adhere a lamina to a receiver element using glass frit paste
US 20120052623 A1
ABSTRACT
A method is provided to adhere a lamina to a receiver element using a glass frit mixture. A donor body having a
previously defined cleave plane and a receiver element are provided. The glass frit mixture is applied to either
the donor body or the receiver element, or both, and is first dried to drive off solvents, then heated to burn out
organics. If the glass frit mixture is applied to the receiver, the receiver element and glass frit mixture may be
heated to the flow temperature of the frit. Following burn out of organics, the glass frit mixture will undergo no
additional outgassing or densification. The receiver element and the donor body are then juxtaposed, the glass
frit layer between them. The structure is heated further to permanently adhere the surfaces and to cleave a
lamina from the donor body at the cleave plane. A device such as a photovoltaic cell is fabricated, the cell
comprising the lamina.
Formed ceramic receiver element adhered to a semiconductor lamina
US 8148189 B2
ABSTRACT
A method is described to create a thin semiconductor lamina adhered to a ceramic body. The method includes
defining a cleave plane in a semiconductor donor body, applying a ceramic mixture to a first face of the
semiconductor body, the ceramic mixture including ceramic powder and a binder, curing the ceramic mixture to
form a ceramic body, and cleaving a lamina from the semiconductor donor body at the cleave plane, the lamina
remaining adhered to the ceramic body. Forming the ceramic body this way allows outgassing of volatiles during
the curing step. Devices can be formed in the lamina, including photovoltaic devices. The ceramic body and
lamina can withstand high processing temperatures. In some embodiments, the ceramic body may be
conductive.
Microwave anneal of a thin lamina for use in a photovoltaic cell
US 8257995 B2
ABSTRACT
A cleave plane is defined in a semiconductor donor body by implanting ions into the wafer. A lamina is cleaved
from the donor body, and a photovoltaic cell is formed which comprises the lamina. The implant may cause
some damage to the crystal structure of the lamina. This damage can be repaired by annealing the lamina using
microwave energy. If the lamina is bonded to a receiver element, the receiver element may be either transparent
to microwaves, or may reflect microwaves, while the semiconductor material absorbs the microwaves. In this
way the lamina can be annealed at high temperature while the receiver element remains cooler.
Apparatus and method for simultaneous treatment of multiple workpieces
US 8207047 B2
ABSTRACT
A system for simultaneously treating multiple workpieces is configured with treatment sites, configured to hold
respective workpieces, fixed on a rotatable base. Treatment stations are equipped with respective active
components operable simultaneously to treat respective workpieces identically on respective aligned treatment
sites. For loading and unloading the treatment sites are rotated through distinct loading and unloading stations of
the treatment stations which allow loading of a second batch while a first batch is being unloaded.
Apparatus and method for simultaneous treatment of multiple workpieces
US 8360409 B2
ABSTRACT
A system for simultaneously treating multiple workpieces is configured with sites, configured to hold respective
workpieces, affixed on a rotatable base. Each site has a shelf accommodating an interior space and may be
positioned by base rotation in alignment with a station of fixed location. Each station is equipped with an active
component. The active components are movable simultaneously within respective stations into the respective
interior spaces of respective aligned sites.
DESCRIPTION
RELATED APPLICATIONS
This application is related to Zuniga et al., U.S. patent application Ser. No. 12/636,410, “Two-Chamber System
and Method for Serial Bonding and Exfoliation of Multiple Workpieces,” and Zuniga et al., U.S. patent application
Ser. No. 12/636,490, “Apparatus and Method for Simultaneous Treatment of Multiple Workpieces,” each filed on
even date herewith, owned by the assignee of the present application, and hereby incorporated by reference.
Method and apparatus for modifying a ribbon-shaped ion beam
US 8089050 B2
ABSTRACT
A ribbon-shaped ion beam is modified using multiple coil structures on a pair of opposed ferromagnetic bars. The
coil structures comprise continuous windings which have predetermined variations along the length of the bar of
turns per unit length. In an example, one coil structure may have uniform turns per unit length along the bar, so
that energizing the coil structures forms a magnetic field component extending across the gap between the bars
with a quadrupole intensity distribution. A second coil structure may have turns per unit length varying to produce
a hexapole magnetic field intensity distribution. Further coil structures may be provided to produce octopole and
decapole magnetic field distributions. The coil structures may be energized to produce magnetic fields parallel to
the bars which vary along the length of the bars, to twist or flatten the ribbon-shaped beam.
2. Background Information
Ribbon-shaped ion beams are known to be used for implanting ions into substrates, particularly semiconductor
substrates as used in the semiconductor manufacturing industry. Typically, such semiconductor substrates
comprise relatively thin wafers of the substrate, commonly formed of monocrystalline silicon. Wafers of
monocrystalline silicon may be circular with a diameter of about 200 or about 300 mm, although other shapes
and dimensions may be used. A ribbon-shaped ion beam can be used for implanting ions into such wafers, in
which case the ribbon-shaped ion beam may be controlled to have an elongate cross-section at the location of
the wafer to be implanted which has a length just greater than the diameter of the wafer. Then, in order to ensure
an even implantation of ions over the entire surface of the wafer, it may be necessary only to produce relative
movement between the ribbon-shaped ion beam and the wafer in a direction perpendicular to the elongate
cross-section direction of the ion beam.
Method and apparatus for modifying a ribbon-shaped ion beam
US 8058626 B2
ABSTRACT
A ribbon-shaped ion beam having an elongate cross-section normal to a beam direction is modified by
generating, at a predetermined position along the ribbon-shaped beam, a magnetic field extending in an xdirection along an x-axis. The x-direction magnetic field has a non-uniform intensity which is a desired function of
x.
2. Background Information
Ribbon-shaped ion beams are known to be used for implanting ions into substrates, particularly semiconductor
substrates as used in the semiconductor manufacturing industry. Typically, such semiconductor substrates
comprise relatively thin wafers of the substrate, commonly formed of monocrystalline silicon. Wafers of
monocrystalline silicon may be circular with a diameter of about 200 or about 300 mm, although other shapes
and dimensions may be used. A ribbon-shaped ion beam can be used for implanting ions into such wafers, in
which case the ribbon-shaped ion beam may be controlled to have an elongate cross-section at the location of
the wafer to be implanted which has a length just greater than the diameter of the wafer. Then, in order to ensure
an even implantation of ions over the entire surface of the wafer, it may be necessary only to produce relative
movement between the ribbon-shaped ion beam and the wafer in a direction perpendicular to the elongate
cross-section direction of the ion beam.
Ion implantation apparatus
US 8324599 B2
ABSTRACT
An ion implanter has an implant wheel with a plurality of wafer carriers distributed about a periphery of the wheel.
Each wafer carrier has a heat sink for removing heat from a wafer on the carrier during the implant process by
thermal contact between the wafer and the heat sink. A respective wafer lift structure on each carrier is moveable
between first and second positions, with the wafer supported spaced away from the heat sink and in thermal
contact with the heat sink respectively. The lift structure is operated to move between the first and second
positions wheel the implant is rotating. This allows control of wafer temperature during the implant process by
adjusting the thermal contact between wafers and heat sinks.
Mirror-image voltage supply
US 8437156 B2
ABSTRACT
A voltage supply incorporates two voltage supplies connected in a mirror-image series arrangement to generate
a DC voltage between the respective common terminals of the voltage supplies.
Bonding apparatus and method
US 8151852 B2
ABSTRACT
A bonding apparatus and method holds first and second bodies peripherally, one above the other, on respective
shelves. A lower heat-transfer body is configured to lift the first body from below and press the first and second
bodies against an upper heat-transfer body to enable bonding between the first and second bodies.
DESCRIPTION
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/122,699, which was
filed on Dec. 15, 2008, by Aditya Agarwal for a APPARATUS AND METHOD FOR MANUFACTURING AN
ASSEMBLY HAVING A THIN LAMINA BONDED TO A BASE SUBSTRATE and is hereby incorporated by
reference.
Bonding apparatus and method
US 8545660 B1
ABSTRACT
A bonding apparatus and method holds first and second bodies peripherally, one above the other, on respective
shelves. A lower heat-transfer body is configured to lift the first body from below and press the first and second
bodies against an upper heat-transfer body to enable bonding between the first and second bodies.
Ion implantation apparatus and a method for fluid cooling
US 7982197 B2
ABSTRACT
A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+
wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is
fixed and the wheel is formed with tensioned spokes supporting a rim carrying the wafer supports. The spokes
may be used for carrying cooling fluid to and from the wafer supports. Detachable connections in the cooling
fluid conduits in the vacuum chamber may comprise tandem seals with an intermediate chamber between them
which can be vented outside the vacuum chamber, or independently vacuum pumped. In one embodiment, a
ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam extends
over the full radial width of wafers on the wheel.
Ion implantation apparatus and a method
US 7989784 B2
ABSTRACT
A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+
wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is
fixed and a ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam
extends over the full radial width of wafers on the wheel. The beam is generated by an ion source providing an
extracted ribbon beam having at least 100 mm major cross-sectional diameter. The ribbon beam may be passed
through a 90° bending magnet which bends the beam in the plane of the ribbon. The magnet provides intensity
correction across the ribbon to compensate for the dependency on the radial distance from the wheel axis of the
speed at which parts of the wafers pass through the ribbon beam.
Ion source assembly for ion implantation apparatus and a method of generating ions therein
US 7939812 B2
ABSTRACT
A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+
wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is
fixed and a ribbon beam of hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam
extends over the full radial width of wafers on the wheel. The beam is generated by an ion source providing an
extracted ribbon beam having at least 100 mm major cross-sectional diameter. The ion source may use coreless saddle type coils to provide a uniform field confining the plasma in the ion source. The ribbon beam may be
passed through a 90° bending magnet which bends the beam in the plane of the ribbon.
Ion implantation apparatus
US 8044374 B2
ABSTRACT
A hydrogen ion implanter for the exfoliation of silicon from silicon wafers uses a large scan wheel carrying 50+
wafers around its periphery and rotating about an axis. In one embodiment, the axis of rotation of the wheel is
fixed and the wheel is formed with tensioned spokes supporting a rim carrying the wafer supports. The spokes
may be used for carrying cooling fluid to and from the wafer supports. In one embodiment, a ribbon beam of
hydrogen ions is directed down on a peripheral edge of the wheel. The ribbon beam extends over the full radial
width of wafers on the wheel.
Selective etch for damage at exfoliated surface
US 7994064 B2
ABSTRACT
Ions are implanted into a silicon donor body, defining a cleave plane. A first surface of the donor body is affixed
to a receiver element, and a lamina is exfoliated at the cleave plane, creating a second surface of the lamina.
There is damaged silicon at the second surface, which will compromise the efficiency of a photovoltaic cell
formed from the lamina. A selective etchant, having an etch rate which is positively correlated with the
concentration of structural defects in silicon, is used to remove the damaged silicon at the second surface, while
removing very little of the relatively undamaged lamina.
Method for preparing a donor surface for reuse
US 8871109 B2
ABSTRACT
A donor wafer, for example of silicon, has an irregular surface following cleaving of a lamina from the surface, for
example by exfoliation following implant of hydrogen and/or helium ions to define a cleave plane. Pinholes in the
lamina leave column asperities at the exfoliated surface of the donor wafer, and the beveled edge may leave an
edge asperity which fails to exfoliate. To prepare the surface of the donor wafer for reuse, mechanical grinding
removes the column and edge asperities, and minimal additional thickness. Following cleaning, growth and
removal of an oxide layer at the surface rounds remaining peaks. The smoothed surface is well adapted to
bonding to a receiver element and exfoliation of a new lamina. A variety of devices may be fabricated from the
lamina, for example a photovoltaic cell.
Isolation circuit for transmitting AC power to a high-voltage region
US 8227763 B2
ABSTRACT
A sequence of series-connected transformers for transmitting power to high voltages incorporates an applied
voltage distribution to maintain each transformer in the sequence below its withstanding voltage.
Methods of transferring a lamina to a receiver element
US 7967936 B2
ABSTRACT
Methods for bonding a donor wafer to a receiver element and transferring a lamina from the donor wafer to the
receiver element are disclosed herein. The donor wafer may be, for example, a monocrystalline silicon wafer
with a thickness of from about 300 microns to about 1000 microns, and the lamina may be may be less than 100
microns thick. The receiver element may be composed of, for example, metal or glass, and the receiver element
may have dissimilar thermal expansion properties from the lamina. Although the lamina and the receiver element
may have dissimilar thermal expansion properties, the methods disclosed herein maintain the integrity of the
bond between the lamina and the receiver element.
Hydrogen ion implanter using a broad beam source
US 7897945 B2
ABSTRACT
Ion implanters incorporating multibeam ion sources are used to meet process dose and energy demands
associated with fabricating a thin lamina for use in photovoltaic devices. The thin lamina are formed by ion
implantation followed by cleaving.
Ion implanter for noncircular wafers
US 7687786 B2
ABSTRACT
Ion implanters are especially suited to meet process dose and energy demands associated with fabricating
photovoltaic devices by ion implantation followed by cleaving.
DESCRIPTION
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to ion implanters for preparing semiconductor lamina, and, in particular, ion implanters
used for economical production of photovoltaic cells.
Ion implanter for photovoltaic cell fabrication
US 7750322 B2
ABSTRACT
Ion implanters are especially suited to meet process dose and energy demands associated with fabricating
photovoltaic devices by ion implantation followed by cleaving.
DESCRIPTION
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of commonly assigned U.S. patent application Ser. No. 12/122,108,
which was filed on May 16, 2008 now U.S. Pat. No. 7,687,786, by Thomas Parrill for a ION IMPLANTER FOR
NONCIRCULAR WAFERS and is hereby incorporated by reference.
Ion implanter for photovoltaic cell fabrication
US 8242468 B2
ABSTRACT
Ion implanters are especially suited to meet process dose and energy demands associated with fabricating
photovoltaic devices by ion implantation followed by cleaving.
DESCRIPTION
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation of U.S. Ser. No. 12/418,237, filed by Thomas Parrill et al. on Apr. 3,
2009, entitled ION IMPLANTER FOR PHOTOVOLTAIC CELL FABRICATION, which is a continuation of
commonly assigned U.S. patent application Ser. No. 12/122,108, issued as U.S. Pat. No. 7,687,786 on Mar. 30,
2010, which was filed on May 16, 2008, by Thomas Parrill for a ION IMPLANTER FOR NONCIRCULAR
WAFERS and is hereby incorporated by reference.
Epitaxial growth on thin lamina
US 20140038329 A1
ABSTRACT
Methods and apparatus are provided for forming an electronic device from a lamina and an epitaxially grown
semiconductor material. The method includes providing a donor body comprising a top surface, epitaxially
growing a semiconductor material on the top surface and implanting the top surface of the donor body with an
ion dosage to form a cleave plane. After implantation, a lamina may be exfoliated from the donor body, wherein
the top surface of the donor body becomes a first surface of the lamina. Exfoliating the lamina forms a second
surface of the lamina, wherein the first surface is opposite the second surface. A metal support may be
constructed on the lamina.
Methods for texturing a semiconductor material
US 20130330871 A1
ABSTRACT
A method for modifying the texture of a semiconductor material is provided. The method includes performing a
first texture step comprising reactive ion etching to a first surface of semiconductor material. After the first texture
step, the first surface of the semiconductor material has a random texture comprising a plurality of peaks and a
plurality of valleys, and wherein at least fifty percent of the first surface has a peak-to-valley height of less than
one micron and an average peak-to-peak distance of less than one micron. Additional texture steps comprising
wet etch or RIE etching may be optionally applied.
Methods for texturing a semiconductor material
US 20130330871 A1
ABSTRACT
A method for modifying the texture of a semiconductor material is provided. The method includes performing a
first texture step comprising reactive ion etching to a first surface of semiconductor material. After the first texture
step, the first surface of the semiconductor material has a random texture comprising a plurality of peaks and a
plurality of valleys, and wherein at least fifty percent of the first surface has a peak-to-valley height of less than
one micron and an average peak-to-peak distance of less than one micron. Additional texture steps comprising
wet etch or RIE etching may be optionally applied.
Method for fabricating backside-illuminated sensors
US 8871608 B2
ABSTRACT
A method for fabricating a backside-illuminated sensor includes providing a thin film semiconductor lamina
having a first conductivity, and forming a doped region having a second conductivity within the lamina and at a
front surface of the lamina. The lamina may be provided as a free-standing lamina, or may be provided as a
semiconductor donor body from which the lamina is cleaved. An electrical connection is formed to the doped
region. A temporary carrier is contacted to the back surface of the semiconductor and later removed. A backsideilluminated sensor is fabricated from the semiconductor lamina, in which the thickness of the semiconductor
lamina remains substantially unchanged during the fabrication process.
Method for three-dimensional packaging of electronic devices
US 8629061 B2
ABSTRACT
An interposer is fabricated from a lamina. A donor body is provided, ions are implanted into a first surface of the
donor body to define a cleave plane, a temporary carrier is separably contacted to the donor body, and the
lamina is cleaved from the donor body. The lamina has front surface and a back surface, with a thickness from
the front surface to the back surface. A via hole is formed in the lamina, where the via hole extends through the
thickness of the lamina. The temporary carrier is removed from the lamina, and the lamina may be fabricated
into an interposer for three-dimensional integrated circuit packages.
Method for forming flexible solar cells
US 8841161 B2
ABSTRACT
The invention provides for a semiconductor wafer with a metal support element suitable for the formation of a
flexible or sag tolerant photovoltaic cell. A method for forming a photovoltaic cell may comprise providing a
semiconductor wafer have a thickness greater than 150 μm, the wafer having a first surface and a second
surface opposite the first and etching the semiconductor wafer a first time so that the first etching reduces the
thickness of the semiconductor wafer to less than 150 μm. After the wafer has been etched a first time, a metal
support element may be constructed on or over the first surface; and a photovoltaic cell may be fabricated,
wherein the semiconductor wafer comprises the base of the photovoltaic cell.
Low-Temperature Method for Forming Amorphous Semiconductor Layers
US 20120258561 A1
ABSTRACT
In embodiments of the present invention an undoped amorphous, nanocrystalline or microcrystalline
semiconductor layer and a heavily doped amorphous, nanocrystalline, or microcrystalline semiconductor layer
are formed on a monocrystalline silicon lamina. The lamina is the base region of a photovoltaic cell, while the
amorphous, nanocrystalline or monocrystalline layers serve to passivate the surface of the lamina, reducing
recombination at this surface. In embodiments, the heavily doped layer additionally serves as either the emitter
of the cell or to provide electrical contact to the base layer. The undoped and heavily doped layers are deposited
at low temperature, for example about 150 degrees C. or less with hydrogen dilution. This low temperature
allows use of low-temperature materials and methods, while increased hydrogen dilution improves film quality
and/or conductivity.
Method to form a device by constructing a support element on a thin semiconductor lamina
US 8173452 B1
ABSTRACT
A semiconductor assembly is described in which a support element is constructed on a surface of a
semiconductor lamina. Following formation of the thin lamina, which may have a thickness about 50 microns or
less, the support element is formed, for example by plating, or by application of a precursor and curing in situ,
resulting in a support element which may be, for example, metal, ceramic, polymer, etc. This is in contrast to a
rigid or semi-rigid pre-formed support element which is affixed to the lamina following its formation, or to a donor
wafer from which the lamina is subsequently cleaved. Fabricating the support element in situ may avoid the use
of adhesives to attach the lamina to a permanent support element; such adhesives may be unable to tolerate
processing temperatures and conditions required to complete the device. In some embodiments, this process
flow allows the lamina to be annealed at high temperature, then to have an amorphous silicon layer formed on
each face of the lamina following that anneal. A device may be formed which comprises the lamina, such as a
photovoltaic cell.
Method to form a device by constructing a support element on a thin semiconductor lamina
US 8518724 B2
ABSTRACT
A semiconductor assembly is described in which a support element is constructed on a surface of a
semiconductor lamina. Following formation of the thin lamina, which may have a thickness about 50 microns or
less, the support element is formed, for example by plating, or by application of a precursor and curing in situ,
resulting in a support element which may be, for example, metal, ceramic, polymer, etc. This is in contrast to preformed support element which is affixed to the lamina following its formation, or to a donor wafer from which the
lamina is subsequently cleaved.
Fabricating the support element in situ may avoid the use of adhesives to attach the lamina to a permanent
support element. In some embodiments, this process flow allows the lamina to be annealed at high temperature,
then to have an amorphous silicon layer formed on each face of the lamina following that anneal.
Zener diode within a diode structure providing shunt protection
US 8536448 B2
ABSTRACT
A structure to provide a Zener diode to avoid shunt formation is disclosed. An undoped or lightly doped
monocrystalline thin semiconductor lamina is cleaved from a donor body which is not permanently affixed to a
support element. The lamina may be annealed at high temperature to remove damage from a prior implant. At
least one aperture is formed through the lamina, either due to flaws in the cleaving process, or intentionally
following cleaving. Heavily doped amorphous silicon layers having opposite conductivity types are deposited on
opposite faces of the lamina, one forming the emitter and one a base contact to a photovoltaic cell, while the
lamina forms the base of the cell. The heavily doped layers contact in the aperture, forming a Zener diode. This
Zener diode prevents formation of shunts, and may behave as a bypass diode if the cell is placed under heavy
reverse bias, as when one cell in a series string is shaded while the rest of the string is exposed to sun.
Method to form a device including an annealed lamina and having amorphous silicon on opposing faces
US 8101451 B1
ABSTRACT
A semiconductor assembly is described in which a support element is constructed on a surface of a
semiconductor lamina. Following formation of the thin lamina, which may have a thickness about 50 microns or
less, the support element is formed, for example by plating, or by application of a precursor and curing in situ,
resulting in a support element which may be, for example, metal, ceramic, polymer, etc. This is in contrast to a
rigid or semi-rigid pre-formed support element which is affixed to the lamina following its formation, or to a donor
wafer from which the lamina is subsequently cleaved. Fabricating the support element in situ may avoid the use
of adhesives to attach the lamina to a permanent support element; such adhesives may be unable to tolerate
processing temperatures and conditions required to complete the device. In some embodiments, this process
flow allows the lamina to be annealed at high temperature, then to have an amorphous silicon layer formed on
each face of the lamina following that anneal. A device may be formed which comprises the lamina, such as a
photovoltaic cell.
Creation of low-relief texture for a photovoltaic cell
US 8349626 B2
ABSTRACT
A novel method is described to create low-relief texture at a light-facing surface or a back surface of a
photovoltaic cell. The peak-to-valley height and average peak-to-peak distance of the textured surface is less
than about 1 microns, for example less than about 0.8 micron, for example about 0.5 microns or less. In a
completed photovoltaic device, average reflectance for light having wavelength between 375 and 1010 nm at a
light-facing surface with this texture is 6 percent or less, for example about 5 percent or less, in some instances
about 3.5 percent. This texture is produced by forming an optional oxide layer at the surface, lightly buffing the
surface, and etching with a crystallographically selective etch. Excellent texture may be produced by etching for
as little as twelve minutes or less. Very little silicon, for example about 0.3 mg/cm2 or less, is lost at the textured
surface during this etch.
Intermetal stack for use in a photovoltaic cell
US 8049104 B2
ABSTRACT
A donor silicon wafer may be bonded to a substrate and a lamina cleaved from the donor wafer. A photovoltaic
cell may be formed from the lamina bonded to the substrate. An intermetal stack is described that is optimized
for use in such a cell. The intermetal stack may include a transparent conductive oxide layer serving as a
quarter-wave plate, a low resistance layer, an adhesion layer to help adhesion to the receiver element, and may
also include a barrier layer to prevent or impede unwanted diffusion within the stack.
Intermetal stack for use in a photovoltaic device
US 8362356 B2
ABSTRACT
A donor silicon wafer may be bonded to a substrate and a lamina cleaved from the donor wafer. A photovoltaic
cell may be formed from the lamina bonded to the substrate. An intermetal stack is described that is optimized
for use in such a cell. The intermetal stack may include a titanium layer in contact with the lamina, which reacts
to form titanium silicide, a non-reactive barrier layer to check the silicide reaction, a low-resistance layer, and an
adhesion layer to help adhesion to the receiver element.
Methods of forming a photovoltaic cell
US 7754519 B1
ABSTRACT
In some embodiments, a method of forming a photovoltaic cell includes (1) forming a cleave plane in a donor
body so as to define a lamina to be bonded to a receiver element and exfoliated from the donor body; (2) prior to
bonding, pre-heating the donor body without the receiver element to a temperature of greater than about 200° C.
for a first time period that is less than a time period required for exfoliation of the lamina from the donor body; (3)
cooling the donor body after pre-heating the donor body; (4) bonding the donor body to the receiver element;
and (5) heating the bonded donor body and receiver element for a second time period so as to complete the
exfoliation of the lamina from the donor body. Numerous other aspects are provided.
Method to make electrical contact to a bonded face of a photovoltaic cell
US 7964431 B2
ABSTRACT
A photovoltaic cell is formed by bonding a donor body to a receiver element and cleaving a thin lamina from the
donor body. Electrical contact is made to the bonded surface of the lamina through vias formed in the lamina. In
some embodiments the emitter exists only at the bonded surface or only at the cleaved surface face; the emitter
does not wrap through the vias between the surfaces. Wiring contacting each of the two surfaces is formed only
at the cleaved face, and one set of wiring contacts the bonded surface through conductive material formed in the
vias, insulated from the via sidewalls.
Back-contact photovoltaic cell comprising a thin lamina having a superstrate receiver element
US 8921686 B2
ABSTRACT
A method to fabricate a photovoltaic device includes forming first and second contact regions at the first surface
of a semiconductor donor body. A cleave plane may be formed by implanting ions into the donor body, and a
lamina that includes the contact regions is cleaved from the donor body at the cleave plane. The first surface of
the lamina may be contacted with a temporary support and fabricated into a photovoltaic device, wherein the
lamina comprises the base of the photovoltaic device.
Method to texture a lamina surface within a photovoltaic cell
US 8178419 B2
ABSTRACT
It is advantageous to create texture at the surface of a photovoltaic cell to reduce reflection and increase travel
length of light within the cell. A method is disclosed to create texture at the surface of a silicon body by reacting a
silicide-forming metal at the surface, where the silicide-silicon interface is non-planar, then stripping the silicide,
leaving behind a textured surface. Depending on the metal and the conditions of silicide formation, the resulting
surface may be faceted. The peak-to-valley height of this texturing will generally be between about 300 and
about 5000 angstroms, which is well-suited for use in photovoltaic cells comprising a thin silicon lamina.
Method to texture a lamina surface within a photovoltaic cell
US 9070801 B2
ABSTRACT
It is advantageous to create texture at the surface of a photovoltaic cell to reduce reflection and increase travel
length of light within the cell. A method is disclosed to create texture at the surface of a silicon body by reacting a
silicide-forming metal at the surface, where the silicide-silicon interface is non-planar, then stripping the silicide,
leaving behind a textured surface. Depending on the metal and the conditions of silicide formation, the resulting
surface may be faceted. The peak-to-valley height of this texturing will generally be between about 300 and
about 5000 angstroms, which is well-suited for use in photovoltaic cells comprising a thin silicon lamina.
Method for making a photovoltaic cell comprising contact regions doped through a lamina
US 7858430 B2
ABSTRACT
In aspects of the present invention, a method is disclosed to form a lamina having opposing first and second
surfaces. Heavily doped contact regions extend from the first surface to the second surface. Generally the
lamina is formed by affixing a semiconductor donor body to a receiver element, then cleaving the lamina from
the semiconductor donor body wherein the lamina remains affixed to the receiver element. In the present
invention, the heavily doped contact regions are formed by doping the semiconductor donor body before
cleaving of the lamina. A photovoltaic cell comprising the lamina is then fabricated. By forming the heavily doped
contact regions before bonding to the receiver element and cleaving, post-bonding high-temperature steps can
be avoided, which may be advantageous.
Photovoltaic cell comprising contact regions doped through a lamina
US 8633374 B2
ABSTRACT
In aspects of the present invention, a lamina is formed having opposing first and second surfaces. Heavily doped
contact regions extend from the first surface to the second surface. Generally the lamina is formed by affixing a
semiconductor donor body to a receiver element, then cleaving the lamina from the semiconductor donor body
wherein the lamina remains affixed to the receiver element. In the present invention, the heavily doped contact
regions are formed by doping the semiconductor donor body before cleaving of the lamina. A photovoltaic cell
comprising the lamina is then fabricated. By forming the heavily doped contact regions before bonding to the
receiver element and cleaving, post-bonding high-temperature steps can be avoided, which may be
advantageous.
Photovoltaic cell comprising a thin lamina having a rear junction and method of making
US 8338209 B2
ABSTRACT
Fabrication of a photovoltaic cell comprising a thin semiconductor lamina may require additional processing after
the semiconductor lamina is bonded to a receiver. To minimize high-temperature steps after bonding, the p−n
junction is formed at the back of the cell, at the bonded surface. In some embodiments, the front surface of the
semiconductor lamina is not doped or is locally doped using low-temperature methods. The base resistivity of
the photovoltaic cell may be reduced, allowing a front surface field to be reduced or omitted.
Photovoltaic Cell Comprising A Thin Lamina Having A Rear Junction And Method Of Making
US 20130087188 A1
ABSTRACT
Fabrication of a photovoltaic cell comprising a thin semiconductor lamina may require additional processing after
the semiconductor lamina is bonded to a receiver. To minimize high-temperature steps after bonding, the p-n
junction is formed at the back of the cell, at the bonded surface. In some embodiments, the front surface of the
semiconductor lamina is not doped or is locally doped using low-temperature methods. The base resistivity of
the photovoltaic cell may be reduced, allowing a front surface field to be reduced or omitted.
Asymmetric surface texturing for use in a photovoltaic cell and method of making
US 7915522 B2
ABSTRACT
A novel surface texturing provides improved light-trapping characteristics for photovoltaic cells. The surface is
asymmetric and includes shallow slopes at between about 5 and about 30 degrees from horizontal as well as
steeper slopes at about 70 degrees or more from horizontal. It is advantageously used as either the front or back
surface of a thin semiconductor lamina, for example between about 1 and about 20 microns thick, which
comprises at least the base or emitter of a photovoltaic cell. In embodiments of the present invention, the
shallow slopes are formed using imprint photolithography.
Asymmetric surface texturing for use in a photovoltaic cell and method of making
US 8410353 B2
ABSTRACT
A novel surface texturing provides improved light-trapping characteristics for photovoltaic cells. The surface is
asymmetric and includes shallow slopes at between about 5 and about 30 degrees from horizontal as well as
steeper slopes at about 70 degrees or more from horizontal. It is advantageously used as either the front or back
surface of a thin semiconductor lamina, for example between about 1 and about 20 microns thick, which
comprises at least the base or emitter of a photovoltaic cell. In embodiments of the present invention, the
shallow slopes are formed using imprint photolithography.
Asymmetric surface texturing for use in a photovoltaic cell and method of making
US 8822260 B2
ABSTRACT
A novel surface texturing provides improved light-trapping characteristics for photovoltaic cells. The surface is
asymmetric and includes shallow slopes at between about 5 and about 30 degrees from horizontal as well as
steeper slopes at about 70 degrees or more from horizontal. It is advantageously used as either the front or back
surface of a thin semiconductor lamina, for example between about 1 and about 20 microns thick, which
comprises at least the base or emitter of a photovoltaic cell. In embodiments of the present invention, the
shallow slopes are formed using imprint photolithography.
Intermetal stack for use in a photovoltaic cell
US 8501522 B2
ABSTRACT
A donor silicon wafer may be bonded to a substrate and a lamina cleaved from the donor wafer. A photovoltaic
cell may be formed from the lamina bonded to the substrate. An intermetal stack is described that is optimized
for use in such a cell. The intermetal stack may include a transparent conductive oxide layer serving as a
quarter-wave plate, a low resistance layer, an adhesion layer to help adhesion to the receiver element, and may
also include a barrier layer to prevent or impede unwanted diffusion within the stack.
Method to form a photovoltaic cell comprising a thin lamina
US 8481845 B2
ABSTRACT
A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a
semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina
from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic
cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving
step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only.
Method to form a photovoltaic cell comprising a thin lamina
US 7842585 B2
ABSTRACT
A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a
semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina
from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic
cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving
step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only.
Method to form a photovoltaic cell comprisinga thin lamina
CN 101510573 A
ABSTRACT
A very thin photovoltaic cell is formed by implanting gas ions below the surface ofa donor body such as a
semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina
from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of aphotovoltaic
cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving
step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only.
Method to form a photovoltaic cell comprising a thin lamina
US 8247260 B2
ABSTRACT
A very thin photovoltaic cell is formed by implanting gas ions below the surface of a donor body such as a
semiconductor wafer. Ion implantation defines a cleave plane, and a subsequent step exfoliates a thin lamina
from the wafer at the cleave plane. A photovoltaic cell, or all or a portion of the base or emitter of a photovoltaic
cell, is formed within the lamina. In preferred embodiments, the wafer is affixed to a receiver before the cleaving
step. Electrical contact can be formed to both surfaces of the lamina, or to one surface only.
Photovoltaic cell comprising a thin lamina having low base resistivity and method of making
US 8129613 B2
ABSTRACT
Fabrication of a photovoltaic cell comprising a thin semiconductor lamina may require additional processing after
the semiconductor lamina is bonded to a receiver. To minimize high-temperature steps after bonding, the p-n
junction is formed at the back of the cell, at the bonded surface. In some embodiments, the front surface of the
semiconductor lamina is not doped or is locally doped using low-temperature methods. The base resistivity of
the photovoltaic cell may be reduced, allowing a front surface field to be reduced or omitted.
Creation and translation of low-relief texture for a photovoltaic cell
US 8563352 B2
ABSTRACT
Low-relief texture can be created by applying and firing frit paste on a silicon surface. Where frit contacts the
surface at high temperature, it etches silicon, dissolving silicon in the softened glass frit. The result is a series of
small, randomly located pits, which produce a near-Lambertian surface, suitable for use in a photovoltaic cell.
This texturing method consumes little silicon, and is advantageously used in a photovoltaic cell in which a thin
silicon lamina comprises the base region of the cell. When the lamina is formed by implanting ions in a donor
wafer to form a cleave plane and cleaving the lamina from the donor wafer at the cleave plane, the ion
implantation step will serve to translate texture formed at a first surface to the cleave plane, and thus to the
second, opposing surface following cleaving. Low-relief texture formed by other methods can be translated from
the first surface to the second surface in this way as well.
Magnetic scanning system for ion implanters
US 20150262863 A1
ABSTRACT
A compact electromagnetic system is disclosed that is capable of scanning an ion beam in two orthogonal
directions (e.g., for semiconductor doping or hydrogen induced exfoliation). In particular, according to
embodiments of the compact electromagnetic system, the steel yoke, pole pieces, and excitation coils for both
the X and Y axis have been integrated into a common structure.
Patents listed but no documentation found:
Two-Chamber System And Method For Serial Bonding And Exfoliation Of Multiple Workpieces
Substrate-Transporting Ion Beam Exfoliation System
System for Measuring the Intensity and Profile of a High Power Ion Beam
Support Substrate for Ion Beam Exfoliation of a Crystalline Lamina
Enhancing the Emissivity of a Donor Substrate for Ion Implantation
A Method of Preparing a Power Electronic Device
Thermal Neutron Generating System and Method
Generating Neutrons Using a Liquid Neutron Source Material
Generating Neutrons Using a Rotating Neutron Source Material