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.