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.



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Hi all;

Now i am making silicon rib waveguide using dry etcing . To decrease the
sidewall roughness as much as possible i plan to use Room T continuous process
instead of Bosch process. Anybody can give some suggstion to increase the etch
rate??

My? process parameter:SF6:C4F8:O2

sccm:5sccm:80sccm,power=800w,time=120s,pressure=10mT,RF power=10w

Andrew