Stoichiometry effects in gaAs epitaxy for ballistic tunneling semiconductor devices

Abstract

The effect of stoichiometry on various features of III‐V compounds are investigated. It is shown experimentally that the optimum vapor pressure of V elements minimizes the deviation from the stoichiometric composition. Vapor pressure control technology is applied not only to the liquid phase epitaxy and bulk crystal growth but also to the surface reaction in molecular layer epitaxy. The surface reaction and kinetic phenomena of GaAs mono‐molecular layer growth by using chemical adsorption of Ga(CH3)3 (trimethyl gallium: TMG) and arsine (AsH3) was investigated. The growth feature was strongly influenced by the surface stoichiometry of arsenic during growth. For example, the diffusion of the doped impurity is affected by the AsH3 amount of supply, the diffusion was prevented by controlling the stoichiometry. The control of stoichiometry was examined systematically and was applied for the device fabrication such as ballistic transistor.