> -----Original Message-----
> From: Lee Tae-Won [mailto:twlee@aerojet.snu.ac.kr]
> Sent: Thursday, December 26, 2002 4:01 AM
> To: mems-talk@memsnet.org
> Subject: [mems-talk] How to fabricate W and Mo
> Dear colleagues.
>
> I'm trying to etch sputtered Mo and W after photo-lithography.
>
> Could you please let me know which wet&dry etchants are
> effective for these materials.

Following is some of our data for W and Mo:

Silicon wet isotropic etchant (126 HNO3 : 60 H2O : 5 NH4F): W = 13 nm/min; Mo >
35 nm/min
H2O2 at 20 C: W = 19 nm/min
H2O2 at 50 C: W = 150 nm/min
XeF2 at 2.6 Torr: W = 80 nm/min; Mo etches
SF6 plasma: W etches; Mo etches
CF4 + O2 plasma: W etches, Mo etches

        --Kirt Williams Agilent Technologies