Reduction of DX Centers in Superlattice Alloy‐Like Material High Electron Mobility Transistors

Abstract

We have characterized two chemical etchants for A1GaInP: hot sulfuric acid (H2SO4, at 60 and 70~ and dilute hydrochloric acid (1HClrlH20, at room temperature). Both chemicals are selective with composition, etching Ga0.sIno.sP slowly, and A10.sIn05P at the rate of several hundred A/s. When used to etch'laser structures, these etchants are anisotropic, resulting in approximate {111} sidewalls. For (A10.TGa0.3)0.sIn0.sP, a common alloy for laser cladding layers, the etching is also dependent upon carrier concentration. For example, while the H2SO4 at 60~ and the 1HCl:lH20 etch n-and un-doped material at a rapid rate, they are very much slower for the p-doped alloy. In contrast, hotter H2SO4 (T -> 70~ is not so selective with doping.

First-principles study of stability of point defects and their effects on electronic properties of GaAs/AlGaAs superlattice

“…[1][2][3][4] Especially, the GaAs/AlAs SL has received wide attention in the applications of high electron mobility transistor (HEMT) and quantum cascade laser (QCL). [5][6][7][8] However, when the SL materials are used in irradiation environments such as aerospace field, [9] high energy physics field, [10] and nuclear physics field, [11] point defects may appear in GaAs/AlAs SL, resulting in the failure of the SL-based devices. [12,13] Thus, it is important to improve the performance of GaAs/AlAs SL structure under irradiation.…”