NanoFab Simulator Update

Nick Reeder, May 17, 2012

Minor Updates

• Thermal Oxidize code: No longer identifies SiO2 as doped after doped Si is oxidized.

• Added ion mill, CF4, and SF6 plasma etches.– Had to make many assumptions, due to scarcity

of data in Williams’ etch-rate tables.• Changed vertical and horizontal scales on

display.– Question: What should height and width of

displayed area be (in microns), and does this need to be adjustable by the user?

Updates to Implant Code

• User now specifies dopant, dose, and ion energy. Code computes depth and doping concentration.

• Thresholds for doping levels:– Undoped if concentration < 1012 ions/cm3

– n or p if 1012 concentration < 1016 – n+ or p+ if 1016 concentration < 1018 – n++ or p++ if 1018 concentration

Updates to Sputter Code

• User now specifies sputtering angle, and code simulates deposition from that angle.

• Fixed: sputter is no longer deposited on shaded surfaces.

• Algorithm is iterative and time-consuming due to complexity of resulting contours.

To-Do List• Write new code for

– Bake– Lift-off– Clean– Profilometer

• Fix spin-coat code so that resist does not adhere to underside of horizontal surfaces.

• In expose code, implement diffraction of UV in air and absorption within resist.

• Add other dry etchants (listed in 3/30/12 meeting).• Fix evaporate, CVD, sputter, oxidize, develop, polish dialog boxes to ask

user for correct parameters, and write code to compute depth from these values.

• Write time-cost-quality code for all operations.• Write online help text.• Produce videos, photos, text for “Learning” tab.

Activity Not started Partial Complete

Simulation coding

Clean X

Spin coat X

Bake X

Mask/Expose/Develop X

Evaporate X

Thermal oxidation X

CVD X

Sputter X

Wet etch X

Plasma etch X

Lift off X

Polish X

Implant X

Track time, cost, quality of each process X

User -interface coding

History with option to revert X

Save/open history files X

Edit colors X

User-defined materials X

Profilometer X

Producing embedded media (videos, photos, etc.) X

Testing X

Documentation X