Ion implantation for carrier lifetime control in silicon technology

Carrier lifetime characterizes the return to equilibrium in a semiconductor by recombination and generation of carriers. Its value affects the performance of many silicon devices. Ion implantation is an emerging method whereby lifetime can be reduced. A major advantage of this method is the possibility of three-dimentional localization of regions of low lifetime within devices and integrated circuits. Argon and proton implantation are discussed as examples of two different approaches to localization; one relies on thermal stability of damage, and the other on the nonuniform energy deposition profile of ions coming to rest in matter. Proton implantation and electron irradiation are compared in an application of lifetime control to insulated gate transistors. It is shown that device performance is improved with proton implantation if the appropriate energy is used. (orig.)