Page 1111 - Basic Electrical Engineering

components like resistors, capacitors, diodes, transistors, etc. and their
interconnections, fabricated into an extremely tiny single chip of silicon. A
chip is an extremely small part of silicon wafer on which an IC is fabricated

or grown. Fig. 17.1 shows a silicon wafer of thickness less than 1mm. The
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wafer contains a large number of square areas usually less than 1cm . A large
number of circuit components along with their interconnections are
accommodated in a single chip.

Figure 17.1 (a) A silicon wafer having a large number of square-shaped chips made on it; (b) a
sample of circuits to be constructed on a single chip

A silicon wafer will contain a large number of square-shaped chips and

each chip will accommodate a large number of circuits. For example, one
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chip of size 4 mm may contain 40 transistors, 35 resistors, a number of
capacitors, and other such components along with their interconnections.
An IC is, therefore, a complete electronic circuit in miniature form grown

into a single chip of silicon. An electronic circuit generally contains a number
of active and passive components. Active components are those which are
capable of producing gains like transistors, FETs, MOSFETs, etc. Passive

components are resistors, inductors, capacitors, etc.
ICs have by and large replaced discrete circuit design using individual

components. ICs can be used to perform specific functions and they can be
replaced as a whole in case any defect occurs in the functioning of the IC.
From the fabrication point of view ICs are classified into monolithic

circuits or hybrid circuits, which uses a combination of different processes.