Open loop temperature controller

Significant characterization and modeling of thermal process to enable closed loop power control for open loop thermal process.

LED process tool

Created temperature control sytem for LED process tool. There were multiple temperature regimes, open & closed loop operation, interference from chamber plasma, gas flow, chamber pressure. Controller was reliable and easy to use.

Single wafer CVD chamber

Rewrote PID controller for single wafer CVD process chamber to improve stability and optimize temperature ramps.

Batch CVD Tool

Developed control strategy for seven zone controller of a batch wafer processing chamber. Conducted extensive experiments to characterize the thermal behavior of each zone. Developed a controller which provided stable, repeatable control for the CVD processes.

Batch ALD Tool

Provided emergency support for a client with poorly-chosen PID settings to eliminate oscillations and provide stable control. Performed thermal characterization experiments and developed PID values for stable control.

MOCVD equipment

Conducted experiments to characterize thermal profiles of each heating zone. Characterize the effects of varying thicknesses of SiC and reflector geometries. Wrote software to compare reflector geometries in different combinations to find the optimal set. Developed thermal models to predict the proper control parameters to produce uniform temperature across the process space.

Device cooler

Performed experiments to derive PID values for Peltier cooler on a sensitive DMD device. Identified thermal power dissipation limits for the cooler across an ambient air temperature range.