Hello guys,

I have a similar problem of glass during ICP deep etching for Si.
In case I try to etch until 200-300 um depth with any etching
mask of PR, SiO2, and Al, it appears for sure.
If you guys have any good solution, pls let me know.

I'd appreciate your help.
Sincerely,
Masahiko
----- Original Message -----
From: "kris" 
To: 
Sent: Monday, October 24, 2005 6:10 AM
Subject: [mems-talk] Grass during polyimide etch


> Hello All,
>
> I have the problem of occurance of grass during
> polyimide etch in O2 plasma.
>
> The polyimide i hvae used was PI2611. I went with low
> power and low pressures for the O2 plasma etch.
> (100mT, 100W). Aluminum was used as a hard mask for
> the polyimide. After etching 15 microns of PI in O2
> plasma, i have observed grass in the etched regions. I
> presume that the grass arised due to the Al sputtering
> during O2 plasma that deposited in the regions where
> the PI was supposed to be etched and finally causing
> the micromasking of the polyimide in these regions
> resulting in grass.
>
> Can somebody suggest me in eliminating the grass.