Chlorine‐Based High Density Plasma Etching of α-Ga2O3 Epitaxy Layer

• Published in: Electronic materials letters 2021, 17(2), , pp.142-147
• Main Authors: Um, Ji Hun, Choi, Byoung Su, Jeong, Dae Hwi, Choi, Hyun-Ung, Hwang, Sungu, Jeon, Dae-Woo, Kim, Jin Kon, Cho, Hyun
• Format: Article
• Language: English
• Subjects: Boron chlorides; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chlorine; Composition effects; Condensed Matter Physics; Density; Discharge; Epitaxy; Gallium oxides; Gas mixtures; Inductively coupled plasma; Magnetics and Photonics; Materials Science; Morphology; Nanotechnology; Nanotechnology and Microengineering; Optical and Electronic Materials; Original Article - Electronics; Plasma composition; Plasma etching; 전자/정보통신공학
• ISSN: 1738-8090; 2093-6788
• DOI: 10.1007/s13391-020-00267-4

High density plasma etching of α-Ga 2 O 3 epitaxy layer was performed in chlorine-based (Cl 2 /Ar and BCl 3 /Ar) inductively coupled plasmas (ICPs) and the effect of plasma composition, ICP source power and rf chuck power on the etch rate and surface morphology has been studied. The α-Ga 2 O 3 etch rate increased as Cl 2 or BCl 3 content in the gas mixture and ICP source power increased, and Cl 2 /Ar ICP discharges produced higher etch rates than BCl 3 /Ar discharges under the conditions examined. Increasing rf chuck power was found to increase the α-Ga 2 O 3 etch rate and to improve surface morphology of the etched field. The highest etch rates of ~ 612 Å/min and ~ 603 Å/min were obtained in 13Cl 2 /2Ar and 13BCl 3 /2Ar ICP discharges under a moderate source power (500 W) and rf chuck power (250 W) condition, respectively. Anisotropic pattern transfer with a vertical sidewall was performed into the α-Ga 2 O 3 layer using a 10Cl 2 /5Ar ICP discharge. Graphic Abstract