XPS study of a selective GaN etching process using self-limiting cyclic approach for power devices application

High quality SiC Epilayers are essential for the development of high performance power devices. Killer defects such as triangular defects could cause leakage current paths within the high voltage SiC devices. This paper reports on the recent advances in 4H-SiC epitaxial growth toward high-throughput production in a commercial planetary reactor. The triangular defects are suppressed by the optimized pre-etching process, and the physics behind was investigated. The doping and thickness uniformities of the intra-wafer and wafer-to-wafer have also been improved.

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P-GaN Gated AlGaN/GaN E-mode HFET Fabricated with Selective GaN Etching Process

JSTS Journal of Semiconductor Technology and Science ◽

10.5573/jsts.2020.20.6.485 ◽

2020 ◽

Vol 20 (6) ◽

pp. 485-490

Author(s):

Won-Ho Jang ◽

Kwang-Seok Seo ◽

Ho-Young Cha

Keyword(s):

Etching Process ◽

Gan Etching

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Low-Damage and Self-Limiting (Al)GaN Etching Process through Atomic Layer Etching Using O2 and BCl3 Plasma

Coatings ◽

10.3390/coatings11030268 ◽

2021 ◽

Vol 11 (3) ◽

pp. 268

Author(s):

Il-Hwan Hwang ◽

Ho-Young Cha ◽

Kwang-Seok Seo

Keyword(s):

Photoelectron Spectroscopy ◽

Schottky Diodes ◽

Atomic Layer ◽

Etching Process ◽

Etching Depth ◽

Self Bias ◽

Number Of Cycles ◽

Etched Surface ◽

Gan Etching ◽

Atomic Layer Etching

This paper reports on the use of low-damage atomic layer etching (ALE) performed using O2 and BCl3 plasma for etching (Al)GaN. The proposed ALE process led to excellent self-limiting etch characteristics with a low direct current (DC) self-bias, which resulted in a high linearity between the etching depth and number of cycles. The etching damage was evaluated using several methods, including atomic force microscopy, photoluminescence (PL), and X-ray photoelectron spectroscopy, and the I–V properties of the recessed Schottky diodes were compared with those of digital etching performed using O2 plasma and HCl solution. The electrical characteristics of the recessed Schottky diode fabricated using the proposed ALE process were superior to those of the diodes fabricated using the conventional digital etching process. Moreover, the ALE process yielded a higher PL intensity and N/(Al + Ga) ratio of the etched AlGaN surface, along with a smoother etched surface.

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Sem Observations in Gastric Mucosa Exposed to Progressive Enzymatic Etching

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s1431927600002531 ◽

1980 ◽

Vol 38 ◽

pp. 570-571

Author(s):

C.A.E. Lemmi ◽

D. Booth ◽

G.E. Adomian

Keyword(s):

Gastric Mucosa ◽

Critical Point ◽

Proteolytic Activity ◽

Etching Process ◽

Cellular Types

In order to enrich populations of homogeneous cellular types we dissociated gastric mucosa by enzymatic techniques. In addition, we used SEM to monitor the progressive etching of the mucosa. Two enzymes were tested: collagenase III with minimum proteolytic activity and Pronase with broader proteolytic effects. The gastric mucosa was exposed to the effect of the enzymes using everted stomach preparations. In this way the digestive action occured progressively from the lumen of the stomach toward the base of the glands. This “etching” process could be monitored conveniently by SEM. After incubation for periods varying from 30 to 210 minutes the tissues were stretched on dental wax, fixed in 2 % glutaralheyde, post-fixed in osmium, dehydrated, critical point dryed and coated with gold. A model MSM-5 “Mini-SEM” was used for observation. Gentle uncurling of the preparation before coating with gold produced fractures which revealed the structure of the gastric glandsin more detail.

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