Diffusion phenomena at the interface between dielectric films and compound semiconductors

Abstract

AbstractThe diffusion phenomena at the interface between dielectric films and compound semiconductors under two kinds of condition (humid or dry thermal) have been studied by means of secondary ion mass spectrometry (SIMS). Under the humid condition—the pressure cooker test at 121 °C, 100% relative humidity and 2 atm—we confirmed that oxygen diffused into dielectric films of SiNx or SiOxNy from the surface and that both Ga and As diffused into films from GaAs substrates simultaneously. Because such diffusion phenomena did not occur under the dry thermal condition at 120 °C, the diffusion was assumed to be influenced by the existence of water vapour. In addition, we investigated the selective diffusion of Ga from AlGaAs into SiOx under the dry thermal condition with rapid thermal annealing. We found that the diffusion velocities depended on the SiOx growing method and the diffusion into SiOx deposited by sputtering was more remarkable than that by plasma chemical vapour deposition Copyright © 2005 John Wiley & Sons, Ltd.