Zinc Diffusion into GaAs1-xPx by Ga-P-Zn Ternary Alloy Source

Abstract

In order to form the p-n junction in Te-doped GaAs_1-x P _x (x=0.4) grown by a Ga-As-PCl₃-H₂ epitaxial system, zinc diffusion by a Ga-P-Zn ternary alloy source is found to be useful. Diffusion is performed by an ampoule diffusion method, and composition of the diffusion source is calculated from the Ga-P-Zn ternary phase diagram. This diffusion source provides high phosphorus overpressure and leads to smaller diffusion coefficients and more planar p-n junctions. Diffusion depth and junction planarity might be less dependent on the GaAs_1-x P _x surface morphology and the degree of crystal perfection. Junction profile is a mixed abrupt-graded type from Capacitance-Voltage measurement. In the result of X-ray micro-probe analysis, a “window effect” is simultaneously revealed by the Ga-P-Zn system diffusion.