"The technology of semiconductor was discovered around 1940's, but it was not widely used until 1970's." (Hong) In these nearly thirty years between, scientists were doing huge amount of researches and analyses about activities upon the atoms and the energy involve. Semiconductors have had a revolutionary impact on science and society. Semiconductor technology and device engineering have developed a symbiotic relationship that connected from the pure physics to the marketplace, and they are now bringing the conveniences to almost every household. This research paper is tended to present the structural phenomena happen in the semiconductor devices; more over, it is to let readers know how American semiconductor industries make effective process on researching. .
In the way of microcosm, we can use the relationship of electron and its energy bands to distinguish differences between conductor, insulators, and semiconductors. Conductors: materials like iron, silver, and copper, the energy bands around the atom are usually overlap; thus their "valence electrons have available continuous distribution of permitted energies" (Beiser). Insulators: materials like diamond, plastic, and glasses, there are forbidden bands that appear because of electrons perfectly fill the valence band and leave off an energy gap in between the two conduction bands in their particle structure. Therefore, the electrons in these materials cannot be emitted freely through their energy levels. Semiconductors: it cannot be found in a pure natural material, it is the combination of two or more elements; because the energy gap "only about 1eV wide"(Beiser) between the two conduction bands is much smaller than the ones in the insulators, it can be increased in conductivity in certain level of energetic strike like increase in light, temperature.
Generally, there are two types of semiconductors: n-type and p-type.