Electronic properties of atomic-layer-deposited high-k dielectrics on GaSb(001) with hydrogen plasma pretreatment

Abstract

In this report, the authors investigate the use of H2/Ar-plasma exposure as a means for achieving high-quality electrical interfaces between p-type GaSb and atomic-layer-deposited Al2O3 dielectric films. Dry in-situ plasma treatments are shown to reduce the estimated density of interface states by over two orders of magnitude compared to a standard wet HCl-treatment, without increasing gate leakage. The chemical compositions of the natively oxidized and treated GaSb surfaces are analyzed via x-ray photoemission spectroscopy (XPS). XPS spectra indicate that the native GaSb oxide is segregated, with Sb-oxide compounds localized at the air interface. Effective H2/Ar-plasma treatments act to remove the Sb-oxide, resulting in a surface Ga-oxide layer enriched in Ga2O3.

Interface Optimization and Modulation of Leakage Current Conduction Mechanism of Yb2O3/GaSb MOS Capacitors with ALD-Driven Laminated Interlayers

“…Similarly, compared to S1, the slight reduction in the Sb–O signal and the increased Sb–Sb bonding state for sample S3 have been found, which may be attributed to the ALD-driven Al 2 O 3 growth on the top. It is reported that the ALD process temperature (200 °C) will induce the degradation in the GaSb MOS interface, and the thermodynamically unstable Sb 2 O 3 tends to react with GaSb to generate Ga 2 O 3 and elemental Sb via the following reaction ,, …”

Effects on the Surface and Luminescence Properties of GaAs by SF6 Plasma Passivation

“…Figures 5a and 6a show the XPS of As 3d and Ga 3d of the samples by SF 6 plasma treatment. In Figure 5a, the Ga-As, As-As, and As-O peaks are found at 40.84 eV [15], 41.55 eV [5], and 44.27 eV [15,16], respectively, and in Figure 6a, the As-Ga, Ga 2 O, and Ga 2 O 3 peaks appear at 19.14 eV [15], 20.24 eV [1], and 20.57 eV [17], respectively. It can be seen that the surface oxidation is severe for untreated GaAs surfaces.…”

“…[1], and 20.57 eV [17], respectively. It can be seen that the surface oxidation is severe for untreated GaAs surfaces.…”

Comparative study of trimethylaluminum and tetrakis(dimethylamido)titanium pretreatments on Pd/Al2O3/p-GaSb capacitors

“…Therefore, as Yokoyama et al have demonstrated [5], lowering the ALD temperature of the high-k film could be helpful in reducing the number of interface defects in the high-k/GaSb system. Additionally, many surface treatments and/or cleaning methods have been applied to improving the high-k/GaSb interface and the electrical properties of MOS capacitors [3][4][5][6][7][8][9][10][11][12][13]. Wet cleaning using various chemicals such as HF, HCl, (NH 4 ) 2 S, and NH 4 OH can remove the defective native oxide and improve the electrical properties [3,9,10].…”

“…However, these may not be sufficient to prevent the re-oxidation of the GaSb substrate during ex situ sample transfer for subsequent high-k film deposition. As an in situ cleaning method, a H 2 plasma pretreatment was also demonstrated to be effective in reducing the native oxide and enhancing the Fermi level movement efficiency [6,[11][12][13].…”