NanoFab Simulator Update

1. NanoFabSimulator Update Nick Reeder, Feb 10, 2012

2. Big Picture • Assumption--Most processes to be simulated involve either: • Adding a layer on top of the wafer (e.g., spin coating, oxidation, evaporation). • Removing a layer from the top of the wafer (e.g., rinsing photoresist, etching oxide, etching metal). • Modifying an existing region without adding or removing material (e.g., exposing photoresist, ion implantation).

3. Current Status • Defined a data structure for modeling the wafer system (body regions plus added layers). • Defined the main program architecture. • Wrote code to add layers (four styles) to the wafer. • Wrote code to remove layers (four styles) from the wafer. • Code incorporates open-source C++ “polygon-clipping” library that performs most of the difficult computational work.

4. Known Bugs/Shortcomings • Code only allows for vertical edges. • Do we need angled edges? High priority? • Selected angles only, or variable? • Do we need curved edges? High priority? • Code for removing layers doesn’t properly handle multiple layers of the same material stacked on top of each other.

5. Next Steps • Fix known bugs/shortcomings. • Other fixes or additions to existing code? • Write code to: • modify an existing region without adding or removing layers. • maintain a history of steps that lets user revert to an earlier step. • model presence of residues or contaminants on surface. • track time, cost, and quality of processes performed. • Define user interfaces for individual resources (spin coater, mask aligner, etc.).