Devices fabricated by ion implantation

Several types of semiconductor devices made by ion implantation will be described, as well as engineering data describing the penetration of B¹¹and p³¹ions in silicon, and typical projected applications to integrated circuits. By ion implantation is meant the process of irradiation of a solid with energetic ions in which the distribution of arrested ions beneath the surface is determined by the target material and by the atomic number, energy, integrated flux, and relative orientation of the incident ions. Energies utilized in this technique are sufficiently high (50 to 400 keV) to minimize sputtering and to produce useful junction depths without using the process of "channeling" between preferred crystal planes. In addition the high energy has allowed fabrication of devices by implantation through a passivating surface oxide, which was previously applied by sputtering at temperatures less than 100°C.