This module aims to introduce students to the principles of semi-custom and full custom design of integrated circuits (IC) for electronic systems. The module is based around the Complementary Metal Oxide Semiconductor (CMOS) integrated circuit process that is used to fabricate the majority of ICs in production today. The module provides insight into the issues involved in IC design through the analysis of examples based around logic gates. Layout design techniques for CMOS logic gates are covered. An understanding of the internals of CMOS ICs will facilitate correct interfacing and choice of clocking strategy. Devices are continually being scaled down in size, hence the term Very Large Scale Integration (VLSI). The effect of such scaling will be discussed with regard to both chip economics and calculation of the improvement in various performance factors such as speed and power dissipation. This information will allow students to make predictions as to the new circuit performance in years to come.