Semiconductor‐insulator Interfaces, High κ Dielectrics on (In)GaAs

Abstract

Recent development of high κ dielectric oxides on (In) GaAs is reviewed in the fields of electronic structure and electric performance; this includes studies of (In) GaAs surfaces with various surface reconstructions, different orientations, and Indium contents, and of high κ/(In) GaAs interfaces. The oxide deposition was carried out using atomic‐layer deposition ( ALD ) and molecular beam epitaxy ( MBE ) via ex‐situ or in‐situ methods. For the former approach, the semiconductor surfaces prior to the oxide deposition were obtained via chemical, arsenic‐cap or annealing treatments. For the latter, the high k's were deposited on pristine freshly MBE ‐grown (In) GaAs surfaces without any treatments. Surface being treated or not clearly determines the quality of the oxide interface which delivers different interfacial electronic structure and electric performance. Without exception, the ex‐situ treated samples show remnant native oxides, which are never found in the in‐situ samples. The electronic structure has been investigated using photoemission measurements, in which the photon energy was provided by X ‐ray and synchrotron radiation. The discussion on high κ/(In) GaAs interfaces has been further extended to the electrical characterization including extraction of interfacial trap densities ( D it 's). Especially, the distinct electrical characteristics of the In 0.2 Ga 0.8 As metal‐oxide‐semiconductor capacitors ( MOSCAPs ) using MBE ‐ Ga 2 O 3 ( Gd 2 O 3 ) and ALD ‐ Al 2 O 3 as the gate are elucidated. Finally, a summary and bench‐marking of the recent advances on enhancement mode III ‐ V (In) GaAs MOSFETs is given, which reveals the great potential of inversion‐channel (In) GaAs MOSFETs for ultimate complementary MOS ( CMOS ) applications.

In-situ atomic layer deposition of tri-methylaluminum and water on pristine single-crystal (In)GaAs surfaces: electronic and electric structures

“…In figure 3(a) of the 2 × 4 surface, the component with the greatest binding energy is the emission from the As-As dimers, which is commonly observed in the literature. See the references listed in [16] and [21]. A sharp LEED image suggests that the As-As dimers here are oriented in a fashion with the long-range order.…”

“…In literature, both in situ [17,20] and ex situ [3,4,6,8] studies of high-κ oxides on (In)GaAs were reported. The former means that a dielectric oxide is deposited on an asgrown (In)GaAs surface, which does not momentarily expose the sample to air whatsoever in either the heterostructure preparation or the measurements of the electronic characteristics [21]. In contrast, an air-exposed (In)GaAs sample is regarded as an ex situ surface, which requires chemical treatments or, if the As is capped, annealing off the capped As in order to obtain a 'clean' surface prior to oxide deposition [21].…”

“…The former means that a dielectric oxide is deposited on an asgrown (In)GaAs surface, which does not momentarily expose the sample to air whatsoever in either the heterostructure preparation or the measurements of the electronic characteristics [21]. In contrast, an air-exposed (In)GaAs sample is regarded as an ex situ surface, which requires chemical treatments or, if the As is capped, annealing off the capped As in order to obtain a 'clean' surface prior to oxide deposition [21]. Both approaches result in different behaviors in the electric characteristics as well as in the interfacial electronic structures.…”

Ultrahigh Vacuum Annealing of Atomic-Layer-Deposited Y2O3/GaAs in Perfecting Heterostructural Chemical Bonding for Effective Passivation

“…After decades of research, , the first GaAs Fermi-level unpinning was realized by using electron beam (e-beam) evaporated Ga 2 O 3 (Gd 2 O 3 ). , Rare-earth (RE) oxides or mixed oxides containing RE elements have effectively passivated numerous semiconductor surfaces in the past decades, from III−V compound semiconductors of GaAs, , InGaAs, , GaSb, and GaN , to group IVs of Ge , and Si , with low D it values. We have used direct e-beam evaporation of Y 2 O 3 in a molecular beam epitaxy (MBE) type (physical vapor deposition) and atomic layer deposition (ALD) (chemical vapor deposition) to effectively passivate the GaAs surface in achieving D it values below 10 12 eV –1 cm –2 .…”

“…After decades of research, 5,6 the first GaAs Fermi-level unpinning was realized by using electron beam (e-beam) evaporated Ga 2 O 3 (Gd 2 O 3 ). 7,8 Rare-earth (RE) oxides or mixed oxides containing RE elements have effectively passivated numerous semiconductor surfaces in the past decades, from III−V compound semiconductors of GaAs, 9,10 This article is licensed under CC-BY-NC-ND 4 InGaAs, 11,12 GaSb, 13 and GaN 14,15 to group IVs of Ge 16,17 and Si 18,19 with low D it values.…”