Question

An oxide coated silicon wafer is patterned (circle of 30 µm diameter) using photolithography and is dipped in HF. After 2 minutes dip, the wafer is examined. The depth of pattern is 1.3 µm and diameter of pattern is 32 µm. Determine the anisotropy of this etching process.
0.769
0.231
1.3
0.3