Dear All, I am a brand new member of Mems Exchange. It is really very nice to have such a community to seek microprocessing advise. My question : 1. I have a trench that it 3 microns deep and 30 microns wide. Can a uniform coating of this trench be obtained by spin coating standard photoresist ? What is the highest aspect ratio feature that can be uniformly coated with standard photoresist ? 2. Is it possible to reliably fill an isolation trench that is 3 microns deep and 30 microns wide with CVD grown SiO2 ? Thank you very much for the help ! Kamesh