Dear Altan Wong,

May i know the minimum dimension of the features you want to etch?

I have etched 500 um thick through-wafer having feature size of 30 um using
a combination of 2 um SiO2 + 9 um AZ9260.

The expose area in your case is quite high, which reduces the etch rate. In
this case, you have to use thick masking layer.

Thanks,
Pradeep Dixit


On 10/15/06, Hsiu-Jen Wang  wrote:
>
> HI all,
>
>    I used AZ 4260 as the mask of DRIE to etch through Si Wafer (
> 500~550um). The origin recipe can reach 19 um thickness of AZ 4620
> (double coating), and the ideal selectivitiy of AZ to Si is 54:1.
> However, 19 um AZ 4620 seems not thick enough in entire process. Is it
> because of too large expose area (Area where want to be etched in
> DRIE)? My expose area is almost 50%. Or can someone suggest me to use
> thicker one like AZ 9260? If so, could some experience be offered? I
> pretty much appreciate it.