2.3.10 points (K5): Draw the etch profile for the mask opening below for both an isotropic and anisotropic <100> silicon wet etch. The etch rate depends upon orientation to crystalline planes. Hint: the angle θ between two planes (u1,v1,w1) and (u2,v2,w2) can be calculated by: cosθ = u1u2 + v1v2 + w1w2.
Isotropic
Anisotropic