Problem stsetch SNF 2010-05-10 16:24:02: More troubles with backside He

The released devices from the E341 class process show significant widening of trenches as the etch progresses. Wafers were etched with the DEEP recipe using the holder. For the duration of the etch, He flow was pegged at the limit of 5 sccm. As a result, cooling was probably not effective, leading to poor sidewall passivation. This is a real problem. Do not clear it just because 1 wafer runs for 10 minutes with the correct flow. Right now, this tool is not usable for critical deep etches.