integrated circuit
    n 1: a microelectronic computer circuit incorporated into a chip
         or semiconductor; a whole system rather than a single
         component [syn: integrated circuit, microcircuit]

	

	integrated circuit
chip
silicon chip

    (IC, or "chip") A microelectronic
   semiconductor device consisting of many interconnected
   transistors and other components.  ICs are constructed
   ("fabricated") on a small rectangle (a "die") cut from a
   Silicon (or for special applications, Sapphire) wafer.  This
   is known as the "substrate".  Different areas of the substrate
   are "doped" with other elements to make them either "p-type"
   or "n-type" and polysilicon or aluminium tracks are etched in
   one to three layers deposited over the surface.  The die is
   then connected into a package using gold wires which are
   welded to "pads", usually found around the edge of the die.

   Integrated circuits can be classified into analogue, digital
   and hybrid (both analogue and digital on the same chip).
   Digital integrated circuits can contain anything from one to
   millions of logic gates - inverters, AND, OR, NAND
   and NOR gates, flip-flops, multiplexors etc. on a few
   square millimeters.  The small size of these circuits allows
   high speed, low power dissipation, and reduced manufacturing
   cost compared with board-level integration.

   The first integrated circuits contained only a few
   transistors.  Small Scale Integration (SSI) brought
   circuits containing transistors numbered in the tens.  Later,
   Medium Scale Integration (MSI) contained hundreds of
   transistors.  Further development lead to Large Scale
   Integration (LSI) (thousands), and VLSI (hundreds of
   thousands and beyond).  In 1986 the first one megabyte RAM
   was introduced which contained more than one million
   transistors.

   LSI circuits began to be produced in large quantities around
   1970 for computer main memories and pocket calculators.  For
   the first time it became possible to fabricate a CPU or even
   an entire microprocesor on a single integrated circuit.  The
   most extreme technique is wafer-scale integration which uses
   whole uncut wafers as components.

   [Where and when was the term "chip" introduced?]

   (1997-07-03)