Effects of GaSb surface preparation on the characteristics of HfO2/Al2O3/GaSb metal-oxide-semiconductor capacitors prepared by atomic layer deposition

Abstract

The electrical, structural, and chemical properties of HfO2/Al2O3/GaSb metal-oxide-semiconductor capacitors (MOSCAPs) fabricated on Sb-rich (2 × 5) and Sb-stabilized (1 × 3) surfaces by atomic layer deposition are characterized. A combination of the transmission electron microscopic, x-ray photoelectron spectroscopic, and atomic force microscopic observations shows that the Sb-rich surface, with its excessive Sb atoms and clusters, leads to island deposition of the dielectric materials and results in the high leakage current of the MOSCAPs. For the MOSCAPs fabricated on the Sb-stabilized (1 × 3) surface, a density of interface traps as low as 8.03 × 1011 cm−2 eV−1 near the valence band and 1.86 × 1012 cm−2 eV−1 at the midgap is obtained as estimated by the conductance method.

Small signal model and RF performance analysis of InAs/GaSb hetero-junction tunneling field effect transistor

“…Interface trap charges of 5 * 10 11 cm −2 were uniformly added between GaSb/HfO 2 interface. This value of trap density was taken from Hsueh et al [19].…”

Brief Review of Surface Passivation on III-V Semiconductor

“…ALD is the most advanced technique for high-k gate material deposition because it offers outstanding film thickness control, pinhole-free and conformal deposition around complex structure. Using ALD for interface passivation prior to gate film deposition has the advantage of in situ processing without any vacuum breaking, which further improve the interface quality, and the "selfcleaning" process [24][25][26][27][28] can reduce and/or removal of native oxides of III-V semiconductors by surface reactions with the ALD precursors during the initial stages of deposition. Passivation by the long-chain alkylthiol SAM have the advantage of environmental friendliness, simple process, low cost, and good treatment effect, but at the same time, needs a relatively long time (for hours) to obtain clean surfaces and well-ordered SAM, which limit its practical application in device processing.…”

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

“…12 On the other hand, unlike Si, GaSb is notoriously sensitive to interface defects and the existence of mid gap states. 13 Thus, to have a high-quality interface with GaSb substrates, the compatibility with GaSb substrates should be considered when selecting the gate dielectrics. Fortunately, high-k dielectrics have realized the possibility to make a high-quality interface for III−V-based CMOS devices.…”