Download Device Fabrication

Microelectronics
&
Device Fabrication
Vacuum Tube Devices
Thermionic valve
Two (di)
Electrodes (ode)
Vacuum Tube Devices
~1940, ENIAC was constructed at the Moore School
Electronic numeric integrator and
computer (ENIAC) (1946) $ 400.000
of Electrical Engineering at the University of
Pennsylvania. It consisted of 19,000 vacuum tubes,
1,500 relays, hundreds of thousands of resistors and
capacitors; all told, including power supply and an air
cooling system, it weighed over thirty tons and
consumed 200 kilowatts of electrical power.
Solid State Devices
• Transistors (BJT, FET, etc.)
• Semiconductor materials can generate and
sense light  OPTOELECTRONIC DEVICES
• They can also sense magnetism, temperature,
pressure  variety of SENSOR devices and
TRANSDUCERS (energy converters) appeared
on the market.
• Although semiconductor diodes and transistors are
still widely used as individual components,
• 1959: Robert Noyce discovered that more than one
transistor could be constructed on a single piece of
semiconductor material.
• Then other components (resistors, capacitors, etc.)
were added with transistors and then
interconnected to form a complete circuit on a
single chip or piece of semiconductor material.
Integrated Circuit (IC) or IC Chip
Smaller and thinner than a dime, this tiny
silicon chip contains millions of transistors that
work together
Steps
• Growth of Semiconductor
• Device Fabrication
– Oxidation
– Patterning (lithography, deposition, etching)
• Packaging
Growth of Semiconductors
1. Growth from a melt (Czochralski Method)
2. Epitaxial Growth: Chemical Vapor-Deposition, LiquidPhase Epitaxy, Molecular Beam Epitaxy
Growth From a Melt: Czochralski Method
Cleaning, sectioning...
 Si Single Crystal Wafer
Device Fabrication Techniques
• Oxidation
Gas
Diffusion of oxygen
SiO2
Silicon
Photolithography
See «How do they make Silicon Wafers and
Computer Chips?» at youtube
Simplified illustration of the process of
fabrication of a CMOS inverter on p-type
substrate in semiconductor microfabrication
Detail of an etch step
Microfabrication
Etching & Deposition
Patterns created with subsequent layers of
photoresist, elemental gas deposition, and/or
etching and metal deposition.Source:
wikicommons
Schematic structure of a CMOS chip,
as built in the early 2000s.