1. NanoFab Simulator Update Nick Reeder, April 20, 2012

2. Update to Legend Legend now displays method of deposition in addition to material.

3. Update to Data Structure To fix bug that we found at last meeting, data structure now allows for holes inside the wafer structure, and etching code handles these holes correctly.

4. New Code: Photolithography Mask New code lets user define, place, and remove mask. Mask can have up to 10 windows. Is that enough? User cannot redefine the mask or perform most other operations (etch, spin coat, deposit layers) while mask is in place.

5. New Code: Expose New code lets user expose resist. Questions: – Is UV exposure top-down only, or does it also work in from the sides? – What parameters should user supply, and how does depth of exposure depend on these? – How is UV exposure of resist affected if other materials lie on top of the resist? Are these other materials affected in any way?

6. New Code: Develop New code lets user develop resist. Simplistic algorithm: removes all exposed positive resist and all unexposed negative resist, and leaves everything else unchanged. Should this be more sophisticated, with user specifying developer and time, as in etch processes?

7. Questions For bake process, should we restrict user’s choice to three options (soft bake, post- exposure bake, hard bake), or let user specify time and temperature? How to model the behavior of the many possible states of photoresist? – Currently have two states: fresh and exposed. – If we keep track of soft bake, expose, post-exposure bake, develop, hard bake, we’ll have at least 32 different possible states. Need a state diagram to show effect on each state of the following operations: soft bake, expose, post-exposure bake, develop, hard bake, plasma etch.

8. ActivityNot startedPartialComplete Simulation coding CleanX Spin coatX BakeX Mask/Expose/DevelopX EvaporateX Thermal oxidationX CVDX SputterX Wet etchX Plasma etchX Lift offX PolishX ImplantX Track time, cost, quality of each processX User -interface coding History with option to revertX Save/open history filesX Edit colorsX User-defined materialsX ProfilometerX Producing embedded media (videos, photos, etc.)X TestingX DocumentationX