The Photochemical Oxidation of GaAs

Abstract

The vacuum ultraviolet photochemical oxidation of normalGaAs by N2O (wavelengths of 2537 and 1849Å) was studied by x‐ray photoelectron spectroscopy. We believe the model most consistent with our data involves (i) adsorption of molecular N2O , (ii) dissociation of the N2O on the surface, and (iii) oxidation of the surface by the adsorbed O atoms. The temperature dependence of the overall reaction on the stoichiometric surface is dominated by the temperature dependence of adsorption of N2O . An As‐rich surface oxidizes more slowly, and the reaction saturates; in this case, the rate‐limiting step and the cause of saturation is the oxidation of the surface by adsorbed O atoms. The As‐covered surface does not present the proper sites (As atoms surrounded by Ga atoms) for fast, continued oxidation of normalGaAs .

Unpinning of the Fermi level on GaAs by flowing water

“…Heating apparently converts any residual insoluble 100. In contrast to deoxygenated water, in which As 0 is insoluble, both As 2 0 3 and As 0 are soluble in oxygenated water. In the next series of experiments, we studied the effects of water saturated with oxygen on as-received and acid etched specimens.…”

“…3 On etched material, most of the bulk oxide is removed, and the surface concentration of As 0 is Increased. The surface Fermi level was found to be pinned on both as-received and etched GaAs.…”

Inverted-Type InAlAs/InAs High-Electron-Mobility Transistor with Liquid Phase Oxidized InAlAs as Gate Insulator

“…One commonly used method to address this issue is to insert a dielectric layer between the metal gate and the In 0.52 Al 0.48 As layer to supply a high energy barrier. Several laboratories have announced successful results related to the preparation of oxide film on semiconductors, such as thermal oxidation [ 12 ], chemical anodization [ 13 ], photochemical oxidation [ 14 ], molecular beam epitaxy (MBE) [ 15 ], and atomic layer deposition (ALD) [ 16 ]. In particular, oxidized InAlAs developed using the UV/ozone process [ 17 ] and wet oxidation [ 18 ] has been reported.…”

Selective Oxidation on High-Indium-Content InAlAs/InGaAs Metamorphic High-Electron-Mobility Transistors

“…Up to now, many efforts have been continuously channeled toward the development of oxidation techniques on the III-V compounds for GaAs-based device application, which include thermal oxidation [1][2][3][4][5][6][7], chemical anodization [8][9][10][11][12], photochemical oxidation [13][14][15][16], plasma oxidation [17][18][19][20], Ga 2 O 3 grown by molecular beam epitaxy (MBE) [21][22][23], Al 2 O 3 grown by atomic layer deposition (ALD) [24], oxidized GaAs or InAlAs prepared by ultraviolet and ozone [25][26][27], and so on. Although the electrical quality of the GaAs-based MOS structures demonstrated to date is not as good as those obtained from the more mature SiO 2 /Si system, some of them have yielded promising results for electronic and optoelectronic applications.…”