It is desired to etch out a region of a silicon dioxide film on the surface of a silicon wafer. The SiO2\nfilm is 100 nm thick. The width of the etched
It is desired to etch out a region of a silicon dioxide film on the surface of a silicon wafer. The SiO2
\r\nfilm is 100 nm thick. The width of the etched-out area is specified to be 650 nm. (a) If the degree of
\r\nanisotropy for the etchant in the process is known to be 1.25, what should be the size of the opening
\r\nin the mask through which the etchant will operate? (b) If plasma etching is used instead of wet
\r\netching, and the degree of anisotropy for plasma etching is infinity, what should be the size of the
\r\nmask opening?