Semiconductors are materials that guide electrical properties between conductors and insulators. We know that the function of a circuit is mainly due to the variety of electric current inside it, and the reason for the formation of current is mainly due to the movement of electrons between metal lines and electronic components (movement / migration). Therefore, the difficulty in the motion of the electrons in the material determines its conductivity. The common metal materials at normal temperature are easy to get energy and generate motion, so the conductivity is good. Because of the characteristics of their materials, the electronic energy of insulator is difficult to get the energy needed for conduction, and few electrons can move inside it, so it hardly conducts electricity. The conductive properties of semiconductor materials are between them, and can be changed by doping impurities to control their conductivity. This is called the dopant properties of semiconductors.
As I said before, the foundation of integrated circuits is transistors. The invention of transistors makes it possible to create integrated circuits, and transistors are based on semiconductors, so semiconductor is also the foundation of integrated circuits. Semiconductors are to integrated circuits, like land to cities. Obviously, the mountains and hills more than those who are not suitable for the construction of the city, sandy soil, limestone in many places are not suitable for the construction of the city. "Build" cities need to choose a good place, and the "integrated" circuit also needs a suitable base material - that is, semiconductors. The common semiconductor materials are silicon, germanium, and gallium arsenide (compound), of which the most widely used and commercially successful "Silicon" is used.
So why semiconductors, especially silicon, are suitable for manufacturing integrated circuits? There are many reasons. Silicon is the most abundant element in the earth's crust, second only to oxygen. There are lots of silicate or silica in the rocks and gravel in nature, which is the reason for the cost of raw materials. The doping characteristics of silicon are easy to control, and it is easy to produce the transistors that meet the requirements, which is the reason of the circuit principle. The silicon dioxide formed by oxidation is stable, and can be used as an excellent insulating film for semiconductor devices, which is the reason of device structure. The key point is the integrated circuit planar technology. Silicon is easier to implement oxidation, lithography, diffusion and other processes. It is more convenient for integration, and its performance is more easily controlled. Therefore, the silicon based integrated circuit knowledge will be introduced later. It will be easier to understand this problem if we know about silicon transistor and IC technology.
In addition to the doping of semiconductor, also has several characteristics of heat sensitivity, photosensitivity, temperature, resistivity negative rectifier, so the semiconductor materials except for the manufacture of large scale integrated circuit, but also can be used for power devices, optoelectronic devices, pressure sensor, thermoelectric refrigeration purposes; processing and utilization of microelectronics technology of super micro, can also be made of MEMS (micro electro mechanical system), used in electronic and medical field.