Properties of the SiO2- and SiNx-capped GaAs(100) surfaces of GaInAsN/GaAs quantum-well heterostructures studied by photoelectron spectroscopy and photoluminescence

Abstract

SiO2 and SiNx layers are routinely deposited onto III-V(100) surfaces at different device processing steps. We elucidate these insulator-interface properties with photoemission and photoluminescence (PL) of SiO2- and SiNx-capped GaAs(100) surfaces of GaInAsN/GaAs quantum wells (QWs). Post-growth annealing led to an increase of the QW-PL intensity, of which origin can be clearly linked to the SiO2 and SiNx interfaces. Concomitantly, Ga2O–related photoemission increased, indicating useful formation of Ga2O at both insulator interfaces. Furthermore, higher Ga-oxidation-state emission, identified with Ga diffused into SiO2 and SiNx, correlates with the blue-shift of the QW-PL wavelength. Also, interfacial As-As related photoemission was identified.

Oxidation of the GaAs semiconductor at the Al2O3/GaAs junction

“…Indeed, it has been previously confirmed that the PL intensity is sensitive to the properties of a thin oxide/III-V interface layer, and higher PL intensity corresponds to lower interface defect density. 1,[31][32][33][34] Therefore, the presented PL results prove that the defect density of the Al 2 O 3 /GaAs interface is reduced by using the pre-oxidized c(4 Â 2)-O layer. It is worth noting that the pure Al 2 O 3 /GaAs sample, used for the comparison, provides a stringent reference because a well-ordered GaAs starting surface, similar to that described previously, 34 was prepared before the ALD growth.…”

Improved Current Collapse Phenomenon in AlGaN/GaN-on-Si HFETs Using Sacrificial GaO_x Process

“…This annealing induced surface damage is responsible for the significant current collapse phenomenon. It is known that Ga atoms tend to more easily diffuse into SiO 2 compared to SiN x [8]. Therefore, it is suggested that a SiN x film is a better choice as a protection layer for GaN surface during high temperature annealing.…”

Decreasing Defect‐State Density of Al2O3/GaxIn1−xAs Device Interfaces with InOx Structures

“…Fitting of peaks arising from different chemical states or energy levels was done using CasaXPS software version 2.3.16 . Here, we focus on the curve fit analysis results of the high resolution As 3d peaks, since effects on Ga bonding have previously been investigated in detail . In our study, Ga 3d, that is commonly used for high resolution characterization of Ga chemical states could not be utilized due to highly intense tail from adjacent O 2s peak.…”

“…Indeed, the nature of these interface defects and the methods to control their formation have been the subject of a vast body of investigations (e.g., refs. ). In previous studies, these defect states have been found to arise, among others, from group‐V dimers; group‐V and group‐III dangling bonds; and III‐Ox or V‐Ox phases.…”

“…Thus, the identification of defect origin(s) is an open issue. There appears to be a consensus that the high oxidation state of Ga (i.e., Ga 2 O 3 type) increases defect density and is more harmful than the corresponding oxides of In . However, the mechanism responsible for Ga 2 O 3 ‐related gap states in Ga x In 1− x As remains unclear.…”