Andrea,

You can deposit PECVD TEOS 4um thickness. TEOS SiO2 etches much faster than
thermal oxide so your photo resist should hold up fine in 7:1 BOE

Best regards,

Glenn

-----Original Message-----
From: Andrea Mazzolari [mailto:mazzolari@fe.infn.it]
Sent: Sunday, December 14, 2008 9:35 AM
To: mems-talk@memsnet.org
Subject: [mems-talk] deposition and patterning of thick SiO2

Hi all,

i need to deposit and pattern 4um of SiO2 on germanium.
Some questions:
1) is it possible to deposit SiO2 on germanium ?
2) is it possible to achieve so thick layers ?
3) is it possible to pattern so thick layers ?

About point 3: i have the possibility to pattern SiO2 with BOE solutions
and S1813 photoresist, but i'm afraid that the photoresist will not
withstand the so long needed etch time.

Best regards,
Andrea