Question

Which type of etching process is preferred to make the photoresist immune to etchants?

(a) None of the mentioned

(b) Wet etching

(c) Plasma etching

(d) Chemical etching

The question was asked by my college professor while I was bunking the class.

Question is taken from Basic Planar Process topic in section IC Fabrication of Linear Integrated Circuits

Answer 1

The accurate option is (c) Plasma etching

Simply put: Plasma etching is also called as dry etching. The major advantage of dry etching process is that, it is possible to achieve smaller line openings (<1µm) compared to other process.