Analysis of InGaN Back-Barrier on Linearity and RF Performance in a Graded-Channel HEMT

• Published in: Journal of electronic materials Vol. 52; no. 2; pp. 1426 - 1436
• Main Authors: Geng, Lixin, Zhao, Hongdong, Yu, Kuaikuai, Ren, Xinglin, Yang, Dongxu, Song, Yiheng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2023; Springer Nature B.V
• Subjects: Barrier layers; Buffer layers; Characterization and Evaluation of Materials; Chemistry and Materials Science; Circuits; Conduction bands; Direct current; Electronics and Microelectronics; High electron mobility transistors; Instrumentation; Linearity; Materials Science; Mathematical analysis; Optical and Electronic Materials; Original Research Article; Radio frequency; Solid State Physics; Transconductance; radio frequency; InGaN back-barrier; linearity; Graded-channel
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-022-10109-8

The linearity and radio frequency (RF) performance of a proposed graded-channel HEMT incorporating an InGaN back-barrier layer is investigated by an Atlas simulator. A W-like shape conduction band energy is formed between the top barrier layer and the buffer layer in the proposed architecture. The direct current and the derivatives of transconductance characteristics are analyzed with an In mole fraction from 0 to 0.07. To further effectively evaluate the device linearity, the linearity figures of merit including VIP 2 , VIP 3 , IIP 3 , and 1-dB compression point are compared between the graded-channel HEMTs with and without an InGaN back-barrier layer. The results indicate that the proposed device shows merit in these parameters, and this is mainly a consequence of the special conduction band shape. Additionally, the RF characteristics are calculated for exploring the high-frequency applications in the proposed device. The flatter transconductance characteristic gives rise to higher linearity but also slightly reduces the maximum f T and f max in the InGaN back-barrier HEMT structures; thus, application-specific trade-offs may need to be considered. The proposed HEMT architecture may be a promising candidate for high-linearity circuit applications.