Dear Thuy, I have good experience in using SU8 2000 series for good adhesion to metals. SU8 3000 I often use for deposition on glass or metaloxides, which works very good. However there are many parameters which can improve the adhesion. When using relatively thick layers, a slow ramp up/down in softbake and postbake is improving  the adhesion due to less stress in the SU8 layer. 

I have  Au metal lines. I tried SU8 10 before. Adhesion to SiO2 was not that bad but to Au was poor. I ordered 1 bottle of SU8 3000 to try. Hope that it works. 

Dear Thuy, I have good experience in using SU8 2000 series for good adhesion to metals. SU8 3000 I often use for deposition on glass or metaloxides, which works very good. However there are many parameters which can improve the adhesion. When using relatively thick layers, a slow ramp up/down in softbake and postbake is improving  the adhesion due to less stress in the SU8 layer. 

Thanks Daniel for sharing your experience. I'll remember that when developing the recipe. I am waiting for the chemical to arrive. This is last step in my device. I am just looking at a passivation layer of around 10 microns. Hopefully I wont have to much stress during baking.

Hello Thuy,

As Daniel suggests, reducing stress in the SU-8 layer is paramount. If you are using a thick glass substrate you may wish to cover the device with a small glass dish to create a more uniform temperature distribution amongst the thick SU-8 layer.

For thicker SU-8 layers you may also wish to use an i-line filter (long-pass optical filter, such as ZJB360, Omega Optical) to prevent T-topping of your features. This, of course, is dependent on how critical the feature dimensions are.

Jules

Thank you very much,Jules for the tips. 

Cheers

Thuy

I agree with Daniel