Fermi-level unpinning in Pt/Al2O3/GaSb PMOS capacitors by sulphurization and rapid thermal annealing of GaSb surfaces

Abstract

A facile route to mitigate the Fermi-level pinning between a p-type GaSb semiconductor and an Al2O3 dielectric is proposed. Combination of the sulphurization of the GaSb surface and the subsequent rapid thermal annealing allowed for high quality GaSb/Al2O3 interfacial characteristics; the interfacial trap density value was ≤2.0 × 1012 cm−2 eV−1 in an energy range of 0.05 ≤ ET − Ev ≤ 0.45 eV for the PMOS capacitor via rapid thermal annealing at 575 °C. A physical rationale was given on the basis of the thermo-chemical conversion of Ga2O into Ga2O3 and the conformal elimination of Sb related elements and oxides on the GaSb surface.

Photoelectric Detectors Based on Inorganic p‐Type Semiconductor Materials

“…When metal oxides are used as the insulators, we can obtain the typical complementary metal–oxide–semiconductor (CMOS) structure and the core component of coupled charge devices (CCDs), which is the fundamental element of modern digital cameras. Many novel CMOS structures based on p‐type semiconductor materials (e.g., Pt/Al 2 O 3 /GaSb MOS structure and SiO 2 /p‐type 4H/SiC MOS structure) are constructed and studied in detail in recent years, which pave new route for the development of new generation CCDs.…”

Surface State Passivation and Optical Properties Investigation of GaSb via Nitrogen Plasma Treatment

“…16,28,38,39,43 These peaks arose from the presence of the surface oxide, Sb clusters existing between the interface of the surface oxide and GaSb substrate, and the GaSb substrate, respectively. 19,36,37 After N passivation (100 W), peaks of Sb–O bonds and Sb–Sb bonds disappeared from the XPS spectra, and peaks of Sb–N bonds at 539.7 eV were observed. 44 However, increasing the plasma power to 200 or 300 W again resulted in the emergence of peaks of Sb–Sb bonds which were related to Sb clusters.…”

“…15−18 This is especially true for GaSb. The performance of GaSb-based devices is suppressed by the presence of surface states, 19,20 which limit the application of GaSb-based devices. Much effort has been focused on reducing the surface states of GaSb.…”

“…These have included incorporating interfacial or capping layers composed of wide band gap materials, wet chemistry modification approaches, in situ hydrogen plasma treatment, and the deposition of high- k dielectrics. 19,21−23 Sulfur (S) passivation has long been recognized as a useful method for removing surface states. 24,25 By adjusting the treatment conditions, the oxide layer and surface dangling bonds can be effectively etched or filled.…”

“…III–V materials possess highly reactive surfaces and a high amount of dangling bonds, so they exhibit a high density of surface states. − This is especially true for GaSb. The performance of GaSb-based devices is suppressed by the presence of surface states, , which limit the application of GaSb-based devices. Much effort has been focused on reducing the surface states of GaSb.…”