Production from 1.31.2008
Good news: We now have much better control/feedback compared to the RIT setup. There are two thermlecouples on the wafer tray that monitors the front and back portion of the wafer. The new unit allows us to independently modify the front/back/bottom lamp power so that we can compensate for any non-uniformity in heating. We also have greater control over the ramp rate, with real-time visualization of the process temperature.
Bad news: none of the three thermal conditions (700 C, 800 C, 900 C) we chose yielded membranes with through-pores.
Two wafers (385, 388) were re-annealed at 1000 C, and are currently awaiting an etch.
RTP temperature profile plot
Wafer 386 – 900 C RTP – 200kx
Our current thought is that a larger thermal budget (ramp rate, steady-state temp) is needed to fully crystallize the room temp. deposited film. The sputter heater re-build is underway, and should be complete by next week.