Hydrogen sil·sesqui·oxane is a metal-free version of these materials whose low dielectric constant makes it ideal for exposure to electrons. Other commonly used examples of these materials include PMMA, DNQ-novolac, and a cross-linked polymer with eight epoxy groups, called SU-8. (10[1])When exposed to a mercury vapor lamp, these materials are differentiable based on whether they expose an area or protect it, leading to their positive/negative distinction. Exposure to plasma (10[1])can remove these materials (10[1])in a process known as ashing. In microfabrication, these (10[1])materials (10[1])are commonly used to mask substrates to protect them from degrading (10[1])during etching. (-5[1])For 10 points, (10[1])name these light-sensitive (10[1])materials (10[2]-5[1])that can (10[2])be used (10[1])to coat silicon wafers in lithography or to create a patterned surface (0[1])in photoengraving. ■END■ (10[4]0[6])