As the people know PMOS and NMOS technology having many drawbacks. In this having speed is very slow and circuit complexity is increased and power dissipation is very high and low noise margin. So the designers are looking for new technology. CMOS was developed in 1963 by the researchers to overcome the drawbacks of PMOS and NMOS. CMOS has its structure similar to PMOS and NMOS but in this both PMOS and NMOS are fabricated on same chip so due to power dissipation is less and speed high.