Q.1 what is deposition in vlsi technology ?

ans-deposition is process by which different material can be deposited on entire substrate surface throw chemical vapor deposition

Is it correct definition for deposition ?

 

Deposition is a broad term in the industry and PVD is just one method of deposition with many implementations.

http://www.princeton.edu/~achaney/tmve/wiki100k/docs/Chemical_vapor_deposition.html
Some other methods.
http://en.wikipedia.org/wiki/Sputter_deposition

 

what is purpose of deposition in vlsi technology I mean why does we deposited number of material onto silicon substrate