Pulsed-jet epitaxy: Application to device processes

Abstract

We report recent activities in the application of pulsed-jet epitaxy (PJE), our new type of atomic layer epitaxy, to device processes. We discuss three major factors of PJE; excellent uniformity of thickness and interface controllability, low-temperature growth and heavy doping, and selective epitaxy. To study the degree of thickness control, we compare the thickness profile of the GaAs epitaxial layer between PJE and MOVPE. The inherent ability of PJE to make a uniform layer is clarified. We find good thickness and interface control of PJE also in the successful fabrication of InAs/InP and GaAs/GaP short-period strained-layer superlattices. Making use of the low-temperature growth and high-concentration Be doping into PJE-grown InGaAs, we fabricate the InGaAs/InP heterojunction bipolar transistor (HBT) structures using a novel PJE/MOVPE hybrid growth process. We show that PJE is a key technology used for making a high-performance HBT. The selective growth of PJE-GaAs shows ideal features in both morphology and thickness uniformity. As an application, we report the formation of a nonalloyed contact layer using selective regrowth of GaAs on a processed substrate.