Dear all,

Thanks a lot for your kind advice. It seems that the problem lies in the high
baking temperature and the use of HMDS. I'll try to make new samples according
to your advice.

All the best,

WANG, Yingnan

 > From: [email protected]
> To: [email protected]
> Date: Mon, 13 Feb 2012 12:34:58 +0000
> Subject: [mems-talk] AZ5214E as positive resist
>
> Dear all,
>
> I am having some trouble in photolithograpy with AZ5214E, which works as
positive resist.
>
> The pattern I want to make is an array of micron dots, with diameter of 3
microns. But no matter how I change the exposure time, I just cannot develop
successfully. I want to know why. The parameters I use are listed below:
>
> Photoresist - AZ5214E
> Substrate - 4" Silicon wafer
>
> Step 1. Clean wafer with Acetone, IPA abd DI
> water and dehydration bake at 150 degrees for 10 minutes.
>
> Step 2: Spin coat HMDS at 4000 rpm for 35
> seconds, without bake.
>
> Step 3: Spin coat AZ5214E at 4000rpm for 45
> seconds and hotplate (110 degrees) bake for 90 seconds.
>
> Step 4: Expose at 8mW/cm^2 for various exposure time, from 10 to 70 seconds.
>
> Step 5: Develop using MIF 300K developer.
>
> Thanks a lot!
>
> All the best,
> WANG, Yingnan