Hi Everyone

As you now have CHF3, you could run our standard oxide etch in your 80+.
This should give you an etch rate of around 400Angstroms/minute, without
removing all your PMMA.
Suggested parameters:
25sccm CHF3
25sccm Ar
30mTorr
200Watts

If you want to run it slower, back off on the power.

Regards,

Martin Walker B.Sc.(Tech.) M.Sc.
Tactical Marketing Engineer
Oxford Instruments Plasma Technology
North End, Yatton, Bristol, BS49 4AP UK
T.+44 (0)1934 837031  F.+44 (0)1934 837001
E. 
W. 

> -----Original Message-----
> Message: 2
> Date: Tue, 15 Jul 2003 01:27:46 +0900
> From: "Sungjun Lee" 
> Subject: [mems-talk] Wet and Dry Etching.
> To: [email protected]
> Message-ID: <[email protected]>
> Content-Type: text/plain; charset="ISO-8859-1"
>
> Dear all:
>
> MEMS is not my major but I need to do a simple process.
> Recently, I have worked SiO2 etching using a PMMA etch
> mask(100nm thickness).
> My goal is to etch SiO2 about 400A depth.(There should be
> PMMA alive for the lift-off process)
> About 300nm is the width of lines written by e-beam lithography.
>
> In wet etching with 25:1 HF, I failed to get some good results.
> (PMMA was peeled off at around 120 seconds, and the etch
> depth is less than 100A during this time)
> Does anyone who use my condition in wet etching?
>
> We have a Oxford Etcher(plasmalab 80+).
> The 100nm-PMMA is nearly wiped-out in my conditions:
> CF4(40sccm) + O2(5sccm) under 50mtorr, 50W for 90 seconds.
> Now, I can use some other gases, Ar, SF6, and CHF3.
> Is there someone who try to other conditions?
>
> Could you please give your invaluable comments to me?
>
> Thanks in advance.
>
> Sungjun / Graduate Student.

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