The development of an integrated circuit (IC) in 1961 wasa great achievement in the field of electronics.But,as there is no end to the man's desire,the growth accelerated further every year.Rapid developments have been made in the integrated circuit technology.Thus starting from the small-scale integration (SSI) in 1961,then medium-scale integration (MSI) in 1966,and large-scale integration (LSI)in 1970.In 2004 we have a very large-scale integration (VLSI) Ultra large -scale integration (ULSI) and Giga-scale integration (GSI).It means that now we have a technology,which can fabricate several million components on a single chip.
   It will be interesting to know that the use of vacuum tube hase become almost obsolete in 1960's.It was replaced by the solid state devices (bipolar transistors and field-effect transistors).Similarly the developments in integrated circuit technology,has made the use of individual transistors as unnecessary.These days,we see all electronic systems made of IC's.The developments which,have taken place in last 60 years,may be understood from the fact that today's microcomputer is several thousand times faster,has a huge memory,million times more reliable,consumes negligible power,occupies 1/100,000 the volume and costs 1/50,000 as compared to the first large electronic computer.
   The microelectronics (term used for the  fabrication of VLSI/ULSI/GSI- circuits)has made a great impact on communication control and computer industries.The applications,which were difficult to realize earlier,have now become possible.In last decade,silicon based technology has dominated the sphere of electronics and will continue to play the role for the next decade as well.However,after that gallium arsenide(Gas) might play a significant role in electronics.