RE the flaking resist problem.  If I were you I'd just do the soft bake for
5-10 minutes.  The hard bake of the AZ resist makes it much less flexible.
We use AZ 4620 in a similar etch all the time with no problems.  We are not
staying in for much more than a minute though.

Good luck.

Jason Tauscher
Senior Fabrication Engineer
Silicon Designs, Inc.
[email protected]
www.silicondesigns.com
(425) 391-8329

----- Original Message -----
From: "Mr. Ritwik Mishra" 
To: 
Sent: Saturday, September 16, 2000 9:52 PM
Subject: HMDS question


> Hi
> I am a graduate student at the Mississippi State University, working on my
> masters in computer engineering with specialization in fabrication. As
> part of my research, I am presently working on a process to remove the
> oxide from the back of a wafer using BOE. In order to preserve the front
> of the wafer we are treating it with HMDS and resist (either AZ1518 or
> SC1827), softbake it at 100C for 45 sec and hardbake at 200C for 2
> min. However during the BOE process after a couple of min the resist is
> starting to flake off causing us to remove the wafer from the BOE bath. As
> a result we have not been able to remove the oxide from back of the wafer.
> We think that we may not be applying HMDS correctly. Do we need a bake
> after HMDS application? It would really help us if you could give us
> some details on the right process.
>
>
____________________________________________________________________________
___
> Mr. Ritwik Mishra
> Department of Electrical & Computer Engineering
> _______________________________________________
>  Research Assistant
>  Affiliations:
>  Mississippi Center for Advanced Semiconductor Prototyping (MCASP)
>  Emerging Material Research Laboratory (EMRL)
>  P. O. Box 4668
>  Mississippi State, MS 39762-4668
>  PHONES (662): MCASP 325-2059, 325-8564    FAX: 662-325-2298
>                EMRL  325-9476/7
>                HOME  320-9393
>
____________________________________________________________________________
____
>
>