Frank,
      If you use vacuum vapor prime you remove all moisture from the surface
then just increasing the time of prime gives control over the contact angle, or
level of hydrophobicity.  Bill Moffat

-----Original Message-----
From: Runkel, Frank [mailto:F.Runkel@suss.de]
Sent: Wednesday, January 22, 2003 10:44 AM
To: 'mems-talk@memsnet.org'
Subject: [mems-talk] RE: Patterning A Hydrophobic Layer


Dear Jessica,

you did not mention if the hydrophobic layer you are looking for needs to
have a certain thickness and what your substrate material is. In case the
substrate is a silicon wafer and the layer could be a monolayer, the easiest
way is to use the adhesion promoter HMDS (hexamethyldisilazane) as the
hydrophobic chemical and pattern it with a standard alkaline developer (KOH,
NaOH).

You may try the following recipe:
1) prime your wafer with HMDS (e.g. heat up the wafer to 120 degC and let it
cool down in a HMDS saturated atmosphere)
3) coat the wafer with any type of a novolak based photoresist (AZ 1512,
S1813, ....)
4) pattern it with an appropriate lithography tool
5) develop it with an alkaline developer
6) remove the photoresist with acetone, NMP, etc.
7) you now have a patterned hydrphobic HMDS monolayer on your wafer

Best Regards,

Frank.

--------------------------------------------
SUSS MicroTec
Applications Center Europe
Frank Runkel
Schleissheimer Str. 90
85748 Garching
Germany
Fon     +49 89 32007 - 302
Fax     +49 89 32007 - 390
email   f.runkel@suss.de



> ------------------------------
>
> Date: Wed, 22 Jan 2003 12:31:45 +0100
> From: Jessica Melin 
> To: mems-talk@memsnet.org
> Subject: [mems-talk] Patterning A Hydrophobic Layer
> Message-ID: 
> Content-Type: text/plain; charset="iso-8859-1" ; format="flowed"
> MIME-Version: 1.0
> Content-Transfer-Encoding: quoted-printable
> Precedence: list
> Reply-To: General MEMS discussion 
> Message: 3
>
> Dear Colleagues,
>
> Am searching for practical information / experience on patterning
> hydrophobic layers. For example, depositing a hydrophobic layer (i.e.
> C4F8) on a silicon substrate, spinning on positive or negative
> photoresist (achieving good coverage with or without the use of an
> adhesive intermediate layer), achieving good lithographic results,
> and etching the hydrophobic layer resulting in a patterned
> hydrophobic layer while the silicon retains its surface properties.
> Alternatively, using a successful lift-off process. Any experiences,
> information, recipes, etc would be greatly appreciated.
>
> Best regards,
>
> Jessica Melin
>
> --
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
> D=
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
> D=
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>     Jessica Melin
>     Royal Institute of Technology
>     Department of Signals, Sensors and Systems
>     Microsystem Technology
>     Osquldas v=E4g 10, 5th floor
>     SE-100 44 Stockholm, Sweden
>
>     Phone:            +46 (0)8 790 9231
>     Fax:                      +46 (0)8 100858
>     Mobile:           +46 (0)73 944 3031
>     Email:            melin@s3.kth.se
>
>     Homepage:         http://www.s3.kth.se/mst
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
> D=
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3
> D=
> =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
>
> ------------------------------
>
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>
> End of MEMS-talk Digest, Vol 3, Issue 17
> ****************************************

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