Multilayered encapsulation of GaAs

Abstract

A method is described by which GaAs may be encapsulated to withstand annealing temperatures over 1100 °C using a double−layered encapsulant consisting of arsenic-doped silicon dioxide on top of plasma-deposited silcion nitride. Samples encapsulated in such a manner and annealed show no signs of mechanical failure and yield higher electrical activation of ion-implanted Se when compared to samples annealed with Si3N4 only. In addition, there is no detectable out-diffusion of Ga or As and no detectable in-diffusion of Si. Peak electrical activation of ion-implanted Se has been measured as 1×1019 carriers/cm3 for samples annealed at 1100 °C. A first-order strain analysis of general multilayered systems is also presented, indicating possible improvements on such an encapsulating procedure for GaAs as well as other compound semiconductors.