Hi H., I happen to have a question along these lines. I am doing a cryo-etching on a ICPRIE oxford machine. I am trying to get vertical smooth side walls 50 u deep in silicon. My SF6 is at 150 sccm and o2 at 16 sccm. Do you happen to know what my power and pressure supposed to be. Thanks a million. Seyed Quoting Huy: > Your etching time is only a couple of minutes, what's the need for a faster > rate? I think you got the right idea, not using the Bosh process would > definately gives you a smoother wall. by using SF6:O2 alone, you can > easily get > a vertical wall with minimum roghness if it's not too tall of a > wall. comparing > to what I've used in the past, your power is only 1/3 and your > pressure is only > 1/10 of what I used; if you can increase those 2 parameters with an > increase of > input gases, you should be able to increase your etching rate. Getting the > right ratio between SF6 & O2 is the only tricky part. > > > H.