The Bardeen, Walter Brattain and William Shockley
The first transistor was developed by John Bardeen, Walter Brattain andWilliam Shockley at Bell laboratories in 1947 enabled the rapid growth of the semiconductortechnology industry. The first integrated circuits of seventies available inmarket had a few hundredstransistors which were manufactured in bipolar technology 29. Bipolar transistors can be either of NPN orPNP silicon structure. In these bipolar transistors, small current into verythin base layer controls large currents between emitter and collector. Basecurrents limit significantly affected the integration density of bipolardevices 29. Bipolar technology delivered high current drive, high performance,high switching speed, smaller propagation delay, but high power consumptionmakes very large scale integration difficult.
B. MOSFETTechnologyFollowing bipolarjunction transistor technology, comes the MOSFET (Metal-Oxide-SemiconductorField Effect Transistor) with very interesting feature of low powerconsumption, low operating voltage, higher speed etc. which make MOSFET usefulin electronics design 20. Two types of MOS transistor PMOS and NMOS are usedfor designing integrated circuits. Both types have very high static power consumption.This problem is overcome by the logic designed in such a way that it consumeslow power in static state.
Frank Wanlass introduces a new logic designed usingtwo complementary p-type and n-type MOSFETs. Two main advantages of CMOStechnology have high noise immunity and very low static power consumption. Since MOSFET consume very low power, it allows a higher level ofintegration. The last several decades have seen innovation of new CMOStechnologies with excellent features.
The trends of MOS integrated circuitsdownsizing is as given below 20: (2D technology from 1970) 10?m -> 8?m -> 6?m ->4?m -> 3?m -> 2?m -> 1.2?m -> 0.8?m -> 0.5?m -> 0.35?m -> 0.25?m-> 180nm -> 130nm -> 90nm-> 65nm -> 45nm -> 32nm -> 28nm (3D technology) -> 22nm (2011) -> 15nm (2013) ->10nm (2015) -> 7nm (2017)