Thermal-assisted contactless photoelectrochemical etching for GaN. (18th March 2020)

• Record Type: Journal Article
• Authors: Horikiri, Fumimasa; Fukuhara, Noboru; Ohta, Hiroshi; Asai, Naomi; Narita, Yoshinobu; Yoshida, Takehiro; Mishima, Tomoyoshi; Toguchi, Masachika; Miwa, Kazuki; Ogami, Hiroki; Sato, Taketomo
• Is Part Of: Applied physics express. Volume 13:Number 4(2020)
• Publication Date: 2020-03-18
• Subjects: GaN -- photoelectrochemical -- etching; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.35848/1882-0786/ab7e09
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: Advanced contactless photoelectrochemical etching for GaN was conducted under the condition that the sulfate radicals (SO4 ·− ) as the oxidizing agent were mainly produced from the S2 O8 2− ions by heat. The generation rate of SO4 ·− was determined from the titration curve of the pH in the mixed solutions between KOH (aq.) and K2 S2 O8 (aq.); it clearly increased with an increase in the S2 O8 2− ion concentration. The highest etching rate of >25 nm min −1 was obtained in the "alkali-free" electrolyte of 0.25 mol dm −3 (NH4 )2 S2 O8 (aq.) at 80 °C, which was approximately 10 times higher than that reported by previous studies.