SemiConductor - What is SemiConductor? Semiconductors are widely used in electronics to make components such as diodes, transistors, thyristors, integrated circuits as well as semiconductor lasers. A semiconductor is usually a solid chemical element or compound that can conduct electricity under some conditions, making it a good medium for the control of electrical current. Its conductance varies depending on the current or voltage applied to a control electrode. Semiconductor is use for manufacturing chips. A semiconductor device can perform the function of a vacuum tube having hundreds of times its volume. A single integrated circuit (IC), such as a microprocessor chip, can do the work of a set of vacuum tubes that would fill a large building and require its own electric generating plant.