Growth of microcrystalline diamond films after fabrication of GaN high-electron-mobility transistors for effective heat dissipation. (14th June 2021)

• Record Type: Journal Article
• Authors: Yaita, Junya; Yamada, Atsushi; Kotani, Junji
• Is Part Of: Japanese journal of applied physics. Volume 60:Number 7(2021)
• Publication Date: 2021-06-14
• Subjects: Diamond -- GaN -- HEMT -- Thermal resistance -- self-heating; Physics -- Periodicals; 621.05
• DOI: 10.35848/1347-4065/ac06d8
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: Diamond films were grown on GaN high-electron mobility transistors (HEMTs) to improve thermal dissipation. We observed the temperature reduction in GaN HEMTs using Raman spectroscopy. The large-grain-size (over 1 μ m) diamond films grown under the ⟨110⟩ preferential growth condition exhibited a high thermal conductivity of over 200 W m −1 K −1 . These diamond films, which were grown at a high temperature of 700 °C, could be directly applied onto the GaN HEMT surface using a thermally stable SiN x metal insulator semiconductor gate structure. The maximum temperature and thermal resistance of the GaN HEMTs decreased by 100 K and from 12.7 mm K W −1 to 7.4 mm K W −1, respectively, when microcrystalline diamond films were applied onto the HEMT surfaces. As a result, the current density and trans-conductance of the GaN HEMTs were improved after diamond-film growth.