High figure of merit extreme bandgap Al0.87Ga0.13N-Al0.64Ga0.36N heterostructures over bulk AlN substrates. (1st January 2023)

• Record Type: Journal Article
• Authors: Hussain, Kamal; Mamun, Abdullah; Floyd, Richard; Alam, Md Didarul; Liao, Michael E.; Huynh, Kenny; Wang, Yekan; Goorsky, Mark; Chandrashekhar, MVS; Simin, Grigory; Khan, Asif
• Is Part Of: Applied physics express. Volume 16:Number 1(2023)
• Publication Date: 2023-01-01
• Subjects: LP-MOCVD -- reverse composition graded contact layer -- linear ohmic contact -- BFOM -- AlGaN channel -- bulk AlN substrate; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.35848/1882-0786/acb487
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: We report on high-quality n -Al0.87 Ga0.13 N-A0.64 Ga0.36 N heterostructures over single crystal AlN. For these pseudomorphic heterostructures, high-resolution X-ray and X-ray Topographic analysis was used to establish a threading dislocation density of 7 × 10 3 cm −2 . Using reverse composition graded n + -Al x Ga1- x N contact layers, we obtained linear ohmic contacts with 4.3 Ω mm specific resistance. A critical breakdown field >11 MV cm −1 was also measured. In combination with the channel resistance of 2400 Ω sq −1, these translate to a Baliga's Figure of Merit of 2.27 GW cm −2 . This, to the best of our knowledge is the highest reported value for extreme bandgap AlGaN heterostructures.