Download kerf- free wafering technology

About SILTECTRA
SILTECTRA is the leading technology specialist for kerf-less wafering processes at low
temperatures. The procedure is a newly-designed platform technology for manufacturing
wafers that can be used in various industries
for a wide variety of brittle materials.
Since 2010 the company has developed processes for the manufacturing of wafers
through splitting and has tailored the wafers to the specific applications in the semiconductor industry. SILTECTRA significantly
reduces process costs and process times for
the various semiconductor materials as well
as semi-finished parts, and allows for an optimized use of resources. In addition, SILTECTRA
KERF-FREE WAFERING
TECHNOLOGY
develops automated solutions for the industry to integrate this innovative procedure into
pre-existing production processes.
SILTECTRA collaborates with selected scientific institutes for semiconductor technology,
photovoltaic, material science and fracture
mechanics, and cooperates with industry
leaders in the photovoltaic and LED sectors
to develop procedures that are tailored to the
market and adapts them to each customer’s
specific requirements.
At its Dresden headquarters SILTECTRA developed an innovative production process for mono-crystalline wafers
and other brittle materials based on a chemical-physical procedure where thermal stress produces forces that split
the crystal along the desired plane. Company founder Dr. Lukas Lichtensteiger of Harvard University in Boston,
Massachusetts discovered the kerf-less procedure that separates wafers without any material loss. The process
was patented in 2008 and since then, SILTECTRA has applied for several other patents.
Innovative deep temperature technologies
for splitting brittle materials
Siltectra GmbH
Manfred-von-Ardenne-Ring 20 | Bldg. E | D-01099 Dresden | Germany
Phone: +49 (0) 351 8925 - 730 | E-Mail: [email protected] | www.siltectra.com
Amtsgericht Dresden HRB 28951 | USt-IdNr.: DE271779981 | Managing Director: Dr. Wolfram Drescher
Commerzbank Dresden | IBAN: DE18 8504 0000 0204 1036 00 | BIC/SWIFT: COBADEFFXXX
KERF-FREE WAFERING
TECHNOLOGY
www.siltectra.com
Wafering
In 2012 close to 60 million square centimeters of silicon
semiconductor wafers were sold worldwide, equaling
a sales volume of 9 billion USD. The current market
volume for silicon carbide is 80 million USD, which is
relatively small. The semiconductor material, however,
is gaining more and more importance, because silicon
carbide is a better heat conductor than silicon and
has superior electrical properties for optical and power
semiconductors.
Gallium nitride is also an important semiconductor
material for power electronics. It currently is not used
SILTECTRA technology creates wafers of diverse semiconductor materials without any
raw material loss – the so-called kerf-loss –
and without damaging the wafer surface. The
wafers can be produced much thinner than the
traditional sawing process, making it possible
to create wafers from expensive materials
such as gallium nitride (GaN) or silicon carbide
(SiC) at various thicknesses and sizes: from a
2 inch gallium nitride wafer to the 450 millimeter silicon wafer, there is no limit to its technology applications.
Photovoltaic
By utilizing this new procedure, new applications and market segments become possible.
The SILTECTRA method pushes the boundaries of technology since the manufacturing of
the next three years gallium nitride’s market volume is
expected to increase to 500 million USD.
Different from conventional wafering which
uses special saws, the SILTECTRA process
does not cause any raw material loss, also
called kerf-loss. This, along with providing a
significantly higher yield, reduces recycling
costs, which can be cost-intensive and often
strictly regulated especially recycling production waste of materials such as gallium arsenide (GaAs) or silicon carbide.
output of more than 100 Gigawatt peak (GWp) have
been installed. By 2020, the German Solar Industry
Association (BSW) expects the worldwide installed
power output to be at least five times its current size.
In 2012 the international photovoltaic market had a
sales volume of almost 59 billion Euro.
very much, since its production is very cost-and-time
intensive, but according to market research, within
To date, worldwide photovoltaic units with a power
semiconductor wafers is no longer limited by
the thickness of the saw-wire, thus producing much thinner wafers. As in silicon carbide
– very often, thinner wafers feature different
physical properties, which can make new applications possible.
WAFERING
When producing a silicon solar cell, creating the
silicon wafer takes up a large part – currently
60 percent – of the manufacturing cost. The
SILTECTRA method splits silicon wafers without any material loss, which reduces the manufacturing cost by up to 30 percent. Worldwide,
solar panels with a total power output of 30
Gigawatt peak (GWp) are installed yearly. Due
to fierce international competition, plans to
reduce the manufacturing cost are in high demand.
Thinning
FRONT-END
The SILTECTRA procedure also allows semifinished cells to be processed. The cells are
processed on both sides and split after doping,
which reduces front-end manufacturing costs
by up to 50 percent – in addition to the aforementioned material savings. Furthermore, the
fracture rate is significantly lower since the
wafers, while being processed, are double the
thickness than conventional solar wafers.
BACK-END (APPLICATIONS)
Along with savings on process materials such
as chemicals and savings on reduced handlingtime, the clean and reflective wafer opens
new back-end application possibilities. For
specific solar cell types, metallization becomes unnecessary or can be reduced. (Metallizing solar cells accounts for approximately
30 percent of the process cost.)
The market for consumable supplies for Chemical and
Mechanical Polish (CMP) has a sales volume of more
than 2.3 billion USD, with an upward trend. Polishing
discs accounts for 27 percent of this sum, and polishing
paste and chemicals make up the remainder. Almost
two thirds of the polishing discs are produced for the
processing of 300 millimeter wafers.
A significant cost driver in the manufacturing
of semiconductor wafers and devices is the
thinning of the wafer to prepare it for its later
applications. Usually the wafer is processed
first and, before any further processing can be
performed, needs to be thinned in a complex
grinding and polishing procedure. This ‘thinning’ of wafers is enormously time-and-cost
intensive.
(LED), for instance, these substrates are responsible for up to 60 percent of the entire
production cost. In case of silicon carbide
LEDs, material cost accounts for 60 percent
of the entire production cost. The thinning
process is time consuming and causes expensive raw material waste that either needs to
be recycled or requires expensive disposal.
Thinning gallium arsenide (GaAs) wafers, for
instance, generates a toxic sludge that, due to
its arsenic content, requires recycling while, at
the same time, the precious gallium needs to
be regained from the waste. This process also
requires large amounts of toxic chemicals.
The time-and-cost-saving SILTECTRA method makes it possible to thin wafers from gallium arsenide by splitting off the desired layer,
which produces neither chips nor sludge.
Occasionally complete backing layers that
are only a vehicle for the manufacturing of
the actual component, are being removed. In
the manufacturing of Light Emitting Diodes
The SILTECTRA method also significantly
reduces the time required to make wafers
thinner, with additional savings on production
means such as abrasives and polishing discs.