Question

If the thickness of wafer after all polishing steps in silicon wafer preparation is 23-40 mils. Find its raw cut slice thickness?

(a) 16-32 mils

(b) 23-40 mils

(c) 8-12 mils

(d) None of the mentioned

This question was posed to me during an online exam.

My doubt is from Basic Planar Process topic in division IC Fabrication of Linear Integrated Circuits

Answer 1

Accurate choice is (a) 16-32 mils

Grasp the essence with: Usually the silicon wafer obtained has a very rough surface due to slicing operation. So, these wafers undergo a number of polishing steps to produce flat and smooth polished surface. Therefore, the thickness of wafers will be reduced from its raw cut slice.