Epitaxial growth of high-quality GaN with a high growth rate at low temperatures by radical-enhanced metalorganic chemical vapor deposition

• Published in: Scientific reports Vol. 14; no. 1; p. 10861
• Main Authors: Dhasiyan, Arun Kumar, Amalraj, Frank Wilson, Jayaprasad, Swathy, Shimizu, Naohiro, Oda, Osamu, Ishikawa, Kenji, Hori, Masaru
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 13.05.2024; Nature Publishing Group; Nature Portfolio
• Subjects: 639/301; 639/301/1005; 639/301/1005/1007; Chemical vapor deposition; Compound semiconductor; Crystals; Flow rates; Free radicals; Gallium; Gallium nitride; GaN/GaN power device; Growth conditions; Growth rate; Humanities and Social Sciences; Low temperature; multidisciplinary; Nitrogen radicals; Photons; Plasma; Radical enhanced metalorganic chemical vapor deposition; Science; Science (multidisciplinary); Vapors; Growth rate; Compound semiconductor; GaN/GaN power device; Radical enhanced metalorganic chemical vapor deposition; Gallium nitride
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-61501-9

Using our recently developed radical-enhanced metalorganic chemical vapor deposition (REMOCVD) technique, we have grown gallium nitride (GaN) on bulk GaN and GaN on Si templates. Three features make up this system: (1) applying very high-frequency power (60 MHz) to increase the plasma density; (2) introducing H 2 and N 2 gas in the plasma discharge region to produce active NH x radical species in addition to nitrogen radicals; and (3) supplying radicals under remote plasma arrangement with a Faraday cage to suppress charged ions and photons. Using this new REMOCVD system, it was found that high-quality crystals can be grown at lower temperatures than that of MOCVD but the disadvantage was that the growth rate was smaller as 0.2–0.8 μm/h than that by MOCVD. In the present work, we have used a pBN inner shield to prevent the deactivation of radicals to increase the growth rate. The growth conditions such as the plasma power, trimethylgallium (TMG) source flow rate, N 2  + H 2 gas mixture flow rate, and the ratio of N 2 /H 2 were optimized and it was found that the growth rate could be increased up to 3.4 μm/h with remarkably high crystalline quality comparable to that of MOCVD. The XRD-FWHM of GaN grown on the GaN/Si template and the bulk GaN substrate were 977 arcsec and 72 arcsec respectively. This work may be very promising to achieve high-power GaN/GaN devices.