I'm depositing a 1.2-1.3 micron PECVD oxide layer with a
Plasma Therm ETP-3 I am getting excellent uniformity and
rate of 200 angs/min OCCASIONALLY. Then the rate and
uniformity gradually or abruptly goes to hell.
Question: what is the order of influence of each variable?
ie Temperature of pallet (250C)
Process pressure (600mTorr)
Power (20W)
N2 flow (600sccm)
N2O flow (600sccm)
5% SiH4 flow (630sccm)
Any information or direction is gratefully appreciated.
Liz