Download Nano-Fab Simulator Layout

NanoFab Trainer
Nick Reeder
[email protected]
June 28, 2012
NanoFab Trainer
• Educational tool that lets user see the results
of performing sequences of basic nanofabrication operations on a silicon (Si) wafer.
• Runs under Windows operating system.
• Written in LabVIEW 2009; requires LabVIEW
2009 Run-Time Engine (free download at
http://joule.ni.com/nidu/cds/view/p/id/1600/lang/en).
User Operations
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Ion implantation (“doping”)
Thermal oxidation
Photolithography
Depositing layers of material
Removing material
Ion Implantation
• Modifies the electrical characteristics of the
silicon wafer. Such modification is the key
technique underlying the operation of
semiconductor devices (diodes, transistors,
thyristors).
• Implanting boron results in “p-type” doping.
• Implanting phosphorus results in “n-type”
doping.
Example: Fabricating a MOSFET
• MOSFET = Metal-oxide-semiconductor field
effect transistor
Thermal oxidation
• Grows a layer of silicon dioxide (SiO2) on the
wafer surface.
• Key properties of SiO2:
– Impervious to ion implantation.
– Can be etched away by immersion in hydrofluoric
acid (HF), which does not etch silicon.
Photolithography
• Steps in photolithography:
– Spin-coat photoresist.
– Create and place mask. Mask defines which
areas will be exposed to UV light and which areas
will be shaded.
– Expose with UV light.
– “Develop” the photoresist: UV-exposed areas are
removed, while shaded areas remain.
• Wikipedia http://en.wikipedia.org/wiki/Photolithography
Depositing Layers
• Methods of depositing layers of material
– Electron-beam evaporation
– Chemical vapor deposition (CVD)
– Sputtering
• The materials deposited may be metals,
dielectrics, or semiconductors.
Removing material
• Methods of removing material
– Wet etching
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Low-tech
Immerse wafer in a bath of liquid acid or solvent
– Dry etching
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High-tech
Expose wafer to plasma beam
Other Features of Trainer
• Maintains history of user operations.
• Will track cost, time, and quality of user
operations.
• “Tutorial” page will provide photos and
videos of operations being performed in the
lab, along with text explaining theory.