Semiconductors form the heart and soul of all modern electronic devices. They have enabled the creation of microprocessors and computers which, in turn, have helped humanity to make great advances in technology. Web designer will not have the necessary tools he need without it; drivers will not have the GPS system if it has never been invented. Basically, every single thing that exists today which uses some form of computer in order for it to function properly depends on semiconductors.
In order to understand how a semiconductor works, we must first examine the material which it is made of. This material is silicon, a common element that can be found in sand and quartz. Most of the semiconductor chips and transistors manufactured today are created using silicon. The element possesses a unique property in its electron structure. Like the element of carbon, it has four electrons in its outer orbital, which allows it to form crystals. These four electrons, by forming perfect covalent bonds with four neighbouring atoms, create a lattice.
In carbon, the crystalline form is the precious diamond. But, in silicon, this crystalline form is a silvery, metallic-looking substance. Though these silicon crystals look metallic, they are not actually metals. Metals have free electrons which can move easily between atoms and, since electricity involves the flow or movement of electrons, metals are good conductors of electricity. However, since silicon crystals are involved in perfect covalent bonds, their electrons cannot move around. In fact, a pure silicon crystal is almost an insulator that allows very little electricity to flow through it. So, how can these silicon crystals be used to make semiconductors whose functions depend on electricity? Continue reading