Explanation

(a) (a) The different processes involved in the fabrication of an $IC$ are
(i) Epitaxial growth of $n$ or $p$-type layer, whenever desired. This involves cracking of silane
(ii) Oxidation which gives a layer of insulating $SiO_{2}$ and can be used to separate one region of the silicon chip from the other
(iii) Photolithography is a processes in which different regions of silicon chip are cur from different components that can be fabricated in different regions
(iv) Diffusion of different impurities to obtain different device structure
(v) Metallisation involves deposition of metal films which inter-connect different components on a chip to obtain the circuit
Hence, option $(a)$ is not involved in fabrication of $IC$