Browsing by Author "Tseng, Yuan-Hung"

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A comprehensive study on the oxidation of 4H-SiC in diluted N2O ambient
(2017-04-01)
Tseng, Yuan-Hung
;
Wu, Tsung-Han
;
Tsui, Bing-Yue
;
Yen, Cheng-Tyng
;
Hung, Chien-Chung
The oxidation mechanism of 4H-SiC in diluted N2O ambient was studied at various temperatures, N2O flow rates, and N-2/N2O flow ratios. The collision partner, N-2 in this study, plays crucial roles in determining the oxidation rate and N-incorporation. According to the proposed oxidation mechanism, lowering the interface state density at lower oxidation temperatures is possible with a high-efficiency collision partner. (C) 2017 The Japan Society of Applied Physics
A comprehensive study on the oxidation of 4H-SiC in diluted N2O ambient
(2017-04)
Tseng, Yuan-Hung
;
Wu, Tsung-Han
;
Tsui, Bing-Yue
;
Yen, Cheng-Tyng
;
Hung, Chien-Chung
The oxidation mechanism of 4H-SiC in diluted N2O ambient was studied at various temperatures, N2O flow rates, and N-2/N2O flow ratios. The collision partner, N-2 in this study, plays crucial roles in determining the oxidation rate and N-incorporation. According to the proposed oxidation mechanism, lowering the interface state density at lower oxidation temperatures is possible with a high-efficiency collision partner. (C) 2017 The Japan Society of Applied Physics
Characterization of LOCOS Field Oxide on 4H-SiC Formed by Ar Preamorphization Ion Implantation
(2017-06-01)
Tseng, Yuan-Hung
;
Lin, Chung-Yu
;
Tsui, Bing-Yue
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this letter, the electrical properties of local oxidation of silicon (LOCOS) field oxide formed on 4H-SiC are reported. Moreover, unlike the conventional Si LOCOS process, a simpler method based on Ar preamorphization implantation is proposed. In addition to direct characterization of the field oxide, device properties achieved using LOCOS isolation are compared with those achieved using the conventional chemical vapor deposition oxide isolation to clarify the impact of isolation technology. The results of this letterwould be insightful for silicon-carbide-basedvery-large-scale integration technology.
Microtrenching-free two-step reactive ion etching of 4H-SiC using NF3/HBr/O-2 and Cl-2/O-2
(2014-05-01)
Tseng, Yuan-Hung
;
Tsui, Bing-Yue
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, the authors performed a reactive ion etch of a 4H-SiC substrate with a gas mixture of NF3, HBr, and O-2, resulting in a microtrenching-free etch. The etch rate was 107.8 nm/min, and the selectivity over the oxide hard mask was similar to 3.85. Cross-sectional scanning electron microscopy showed no microtrenching compared with etches using plasmas of NF3, NF3 /HBr, and NF3/O-2. Analyzing a variety of HBr/O-2 mixing ratios, the authors discuss the additive effect of each gas and their respective potential mechanisms for alleviating microtrenching. To increase the radius of gyration of the bottom corners, they introduced a second etch step with Cl-2/O-2 plasma. Fabricating simple metal-oxide-semiconductor capacitors on the two-step etched surface, the authors found that the electrical characteristics of the etched sample were nearly the same as the nonetched sample. (C) 2014 American Vacuum Society.
Trenched 4H-SiC with tapered sidewall formed by Cl-2/O-2 reactive ion etching
(2016-11)
Tseng, Yuan-Hung
;
Tsui, Bing-Yue
;
電機學院
;
電子工程學系及電子研究所
;
College of Electrical and Computer Engineering
In this article, trenches with various sidewall slant angles were generated on 4H silicon carbide substrate using Cl-2/O-2-based reactive ion etching. A series of experiments was conducted to investigate the effects of chamber environmental conditions, including Cl-2/O-2 mixing ratios, radio frequency power, and process pressure. The results indicate that the chamber pressure, ion energy, redeposition of etch products/byproducts, and even the existence of photoresist are critical factors affecting the slant angle. The introduction of oxygen not only changes the etch profile but may also cause a serious problem known as the micromasking effect. A method combining photoresist and hydrofluoric acid clean was proposed to eliminate the micromasking effect while keeping the sidewall passivation. (C) 2016 American Vacuum Society.