CMUTs Parametric Array

dummy wafer 1

blackbox No.25

SOI wafer

blackbox No.23

After exposure, there are some debris, which is from omnicoat layer. 

After removing Su8 photoresist, we can easily see the color of omnicoat is like green. 

omnicoat etch

After removing omnicoat layer, Al2O3 in the hole is exposured. 

•  etch Al2O3 in holes

• picture color is incorrect due to microscope issue

• outside holes, covered by Al2O3 and SU8