With the implementation of the CMOS inverter, NOR gate and NAND gate, initially using discrete transistors however, the CMOS concept took root, demonstrating the low power dissipation characteristics. Initially, requirement of more complex processing technology and larger silicon area compared to the single polarity transistors led to limited application of CMOS transistors to general system designs. However, as CMOS technology rapidly improved to support large chip sizes, and the issue of power consumption became more and more critical, CMOS technology has firmly established itself as the dominant VLSI technology.

This first chapter introduces the reader to CMOS logic design and design representations.

Over the past two decades, Complementary Metal Oxide Silicon (CMOS) technology has played a very important role in the global integrated circuit industry. Although the basic principle of the MOS field-effect transistor was explained by J. Lilienfeld in 1925, commercial success of MOS devices could be ensured only during the 1960s with the invention of the silicon planar process. Nevertheless, the nMOS devices, fabricated by the nMOS-silicon-gate technology, came to be used in the early 1970s, prior to which only single-polarity p-channel transistors were in use. At the same time, P.K. Weimer and F. Wanlass demonstrated the possibility of using both polarity devices on the same substrate.