Measurements of minority-carrier lifetimes ( tau ) in shallow-junction GaAs LEDs under varying gas-pressure conditions prior to and following gamma irradiation indicate (1) tau is noticeably influenced by gaseous ambient and, (2) this influence is greater following irradiation than prior to irradiation. This dependence of tau upon surface phenomena indicates gamma irradiation changes surface conditions considerably. Combination of both mechanisms on surface effects can be utilized to bring about noticeable improvement in diode speed of response using only modes dosages of nuclear irradiation (up to 60% improvement for only 13 Mrad). It is believed that gamma irradiation affects trap density particularly, while changes in gas type and pressure change both trap density and electron capture cross sections at the surface through adsorption-desorption processes. This is believed to be the first time gamma ray induced decrease of tau has been studied in different post-irradiation gaseous environments.
|Number of pages||5|
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|State||Published - 1 Oct 1984|