You can sputter on the tungsten.

Because tungsten does not have good adhesion to SiO2 (or to SiNx), first
sputter on a 50-100 A layer of Ti, TiN, TiW, Cr, or another adhesion layer.
Then sputter on the tungsten without breaking vacuum. Thus, you need a
sputtering system with multiple targets.

For an example of a process flow to deposit and pattern tungsten, see
http://web.archive.org/web/20011125113849/www-
bsac.eecs.berkeley.edu/archive/kirt_williams_phd.zip ,
file Ch7_proc.flow.pdf, p. 174.

If you want to deposit thicker tungsten, you'll probably need to work on
stress control by varying the pressure or power until the stress is low.
If not, the film will delaminate or break the wafer.

    --Kirt Williams

----- Original Message -----
From: "Pothisorn, Araya - potay006" 
To: 
Sent: Thursday, October 09, 2008 8:41 PM
Subject: [mems-talk] How to deposit Tungsten blanket on Oxide layer


> Hi all,
>
> I'm new in MEMS. Does anyone have experience in deposit tungsten on
> Oxide layer? I need to deposit 1000 angstorm of tungsten blanket on the
> oxide layer.
>
> Regards,
>
> Araya