Question

How the aluminium film coating is carried out in metallization process?

(a) Heating and pouring aluminium in required place.

(b) Aluminium is vacuum evaporated and then condensed

(c) Placing the aluminium in required place and then heating it using tungsten

(d) None of the mentioned

This question was posed to me in unit test.

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

Answer 1

Accurate choice is (b) Aluminium is vacuum evaporated and then condensed

Here's an easy explanation: Metallization process takes place in Vacuum evaporation chamber, where the material is evaporated by focussing a high power density electron beam. Vapours then hit the substrate and get condensed to form thin film coating.