Dear All,
    I am making some of kind of  simple patterned wafer which will be used as
test piece for our scanning sensor system. The requirement is that the sample
needs to be protected by a passivation layer which is hardly able to be
scratched since the sensor is in contact scanning. I tried to use SiO2 done by
either PECVD or recative sputtering, but none of them works. I also tried
photosensitive polymide material(PI 2771), but it is kind of soft aftere curing
at 350C as suggsted by vendor. Does any one have any experience with that?

Thanks

Xiaoyong