Integrated- circuit resistors

Increasingly, whole electronic circuits are being fabricated on semiconductor wafers known as integrated circuits (ICs). It is possible nowadays to put a whole radio receiver into a couple of ICs, or chips, whose total volume is about the same as that of the tip of your little finger. In 1930, a similar receiver would have been as large as a television set. Resistors can be fabricated onto the semiconductor chip that makes up an IC. The thickness, and the types and concentrations of impurities added, control the resistance of the component.
IC resistors can only handle a tiny amount of power because of their small size. But because IC circuits in general are designed to consume minimal power, this is not a problem. The small signals produced by ICs can be amplified using circuits made from discrete components if it is necessary to obtain higher signal power.