[mems-talk] Best plasma chemistry for SiO2/Si selectivity

[Satish Yeldandi]

Hello Rashmi

Thanks for the reply. I am using 400W ICP, 100W RIE and 10mT pressure.
CF4+O2 combination is going to etch both Si and SiO2 right. How am i
gonna get good selectivity. I dont have CHF3 gas with that system. Any
suggestion for the flow rates of CF4 and O2?

~Satish

On Thu, Apr 10, 2008 at 3:40 PM, Rashmi Rao <rao.rashmi at gmail.com> wrote:
> Satish,
>
>  What is the power and pressure regims that you are using.
>  Typically it is better to use CF4 with O2 to etch SiO2 and this usually has
>  very good selectivity between Si and SiO2.
>
>  The C: F ratio determines the selectivity.
>  You can also try a combination of CF4/CHF3/O2.
>
>  Rashmi