Electrical compensation and cation vacancies in Al rich Si-doped AlGaN

Abstract

Note: This paper is part of the Special Topic on Ultrawide Bandgap Semiconductors.

Identification of Point Defects in Multielement Compounds and Alloys with Positron Annihilation Spectroscopy: Challenges and Opportunities

“…In addition to the complication of interpretation of the defect signals from the point of view of exact identification, this sensitivity to the surroundings also brings benefits. As shown in previous studies, [56,57] deviations from the random alloy nature of the material, or preferential formation of vacancy defects in regions rich in one of the constituents [38,56,57] where they are discussed in detail as well as their uncertainties. The thick segments of the dashed V Ga -V In and V Ga -V Al lines show the predicted scatter for cation vacancy values in In 0.5 Ga 0.5 N and Al 0.5 Ga 0.5 N, respectively.…”

“…In addition to the complication of interpretation of the defect signals from the point of view of exact identification, this sensitivity to the surroundings also brings benefits. As shown in previous studies, [ 56,57 ] deviations from the random alloy nature of the material, or preferential formation of vacancy defects in regions rich in one of the constituents naturally occurring due to the fluctuations in random alloy, can be studied by conducting systematically designed experiments. Similar phenomena have been observed earlier in Si–Ge alloys where nearest‐neighbor distributions strongly affect not only the annihilation characteristics of point defects but also their physical characteristics.…”

“…Relative S and W parameters in GaN, InN, and AlN and their alloys. These parameters are determined by combining experiments (full markers) and theoretical calculations (empty markers) in the studies by Ishibashi and Uedono; Prozheeva et al; and Prozheev et al,[38,56,57] where they are discussed in detail as well as their uncertainties. The thick segments of the dashed V Ga -V In and V Ga -V Al lines show the predicted scatter for cation vacancy values in In 0.5 Ga 0.5 N and Al 0.5 Ga 0.5 N, respectively.…”

AlGaN multiple quantum well deep‐ultraviolet micro‐light‐emitting diodes for high color conversion efficiency quantum dots display

“…As the AlGaN epi‐layer on AlN buffer was grown with compensating defects such as Al or Ga vacancies, 22 cracks and hillocks were detected on the epi‐wafer surface by atomic force microscope (AFM). The morphology of a 10 × 10 μm 2 area revealed the surface roughness ( R q ) was 55.48 nm.…”

Defects in nitride semiconductors as seen by positrons

“…In this paper the focus is on the recent results obtained in high Al content AlGaN alloys, and GaN/AlGaN high electron mobility transistors (HEMTs). [11][12][13] Combining positron annihilation experiments with state-of-the-art theoretical calculations allows to identify N vacancies at the GaN/AlGaN interface in the HEMT structures. In the AlGaN alloys, the cation vacancies compete with other negatively charged defects in determining the level of electrical compensation and hence conductivity in n-type doped material.…”