> -----Original Message-----
> From: Kristin J. Lynch [mailto:high_g_rocket_boy@hotmail.com]
> Sent: Monday, February 10, 2003 1:20 PM
> To: mems-talk@memsnet.org
> Subject: [mems-talk] Chemical Durability of SiO2
>
> Is there a difference in chemical durability of SiO2 produced as
> a thin film vs. SiO2 produced in the bulk?  (i.e. a silicon wafer
> coated with an oxide vs a quartz plate.)
>
> Thanks
> Kristin

Based on etch-rate tests in several different etches,
the "chemical durability" of thermally grown SiO2 and
wafers of fused quartz (not crystalline quartz) are about the same.
Deposited SiO2, whether LPCVD or PECVD, generally etches faster than these.

        --Kirt Williams Agilent Technologies