An additional thought to Charles's message.  Vacuum Vapor Prime HMDS can help.
With aluminum it requires about a 20 minute prime time to achieve the same
surface tension as a 5 minute prime time on SiO2.  If you have a YES primer try
20 minutes as the prime time.  Bill Moffat
-Original Message-----
From: Charles Ellis [mailto:[email protected]]
Sent: Wednesday, November 12, 2003 4:26 PM
To: 'General MEMS discussion'
Subject: RE: [mems-talk] Adhesion problem Between Aluminium and
Photoresist


A few thoughts

1.) Your should be using PAE (16-1-1-2) or equivalent to etch Aluminum.

2.) Your need to oxidize the surface of your aluminum before applying
Photoresist. I do it one of two ways. Dehydration bake at 120 C - 200 C
(careful - high temp may cause hillocking), or O2 clean in an asher or
plasma system. Either way will grow a thin oxide and help adhesion. HMDS
will help some, but not usually necessary.

3.) Make sure and hard bake your photoresist ~120 C.


Good Luck,
Charles Ellis,
Director, Auburn University Microelectronics Laboratory