Hello Dear Reader, Credits of this complete article go to my classmates Jimmy Patel, Abhishek Pandya, Sony Dudhe, Nikul Panchal they have given us a very short summary of the substructure of the CMOS device.   CMOS Fabrication: For less power dissipation requirement  CMOS technology  is used for implementing transistors. If we require a faster circuit then transistors are implemented over  IC using   BJT . Fabrication of  CMOS transistors  as IC’s can be done in three different methods. The N-well / P-well technology, where n-type diffusion is done over a p-type substrate or p-type diffusion is done over n-type substrate respectively. The  Twin well technology , where  NMOS  and PMOS transistor  is developed over the wafer by simultaneous diffusion over an epitaxial growth base, rather than a substrate. The silicon On the Insulator process, where rather than using silicon as the substrate an insulator material is used to improve speed and latch-up susceptibility.   N- well/ P- well T