N2O treatment enhancement-mode InAlN/GaN HEMTs with HfZrO2 High-k insulator

• Published in: Microelectronics and reliability Vol. 55; no. 1; pp. 48 - 51
• Main Authors: Chiu, Hsien-Chin, Wu, Chia-Hsuan, Chi, Ji-Fan, Chyi, J.-I., Lee, G.-Y.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2015
• Subjects: E-mode; GaN; HEMTs; HfZrO2; InAlN; E-mode; HEMTs; InAlN; GaN; HfZrO2
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/j.microrel.2014.09.026

•E-mode InAlN/GaN MIS-HEMT with HfZrO2 gate insulator was realized.•N2O plasma treatment oxidized 13nm InAlN Schottky layer.•High-k thin film HfZrO2 was used for gate insulator of E-mode device.•The low frequency noise is attributed to the mobility fluctuation. A normally-off InAlN/GaN MIS-HEMT with HfZrO2 gate insulator was realized and investigated. By using N2O plasma treatment beneath the gate region, 13nm InAlN Schottky layer was oxidized to AlONx+4nm InAlN Schottky layer. The strong polarization induced carriers in traditional InAlN/GaN 2 DEG quantum well was reduced for enhancement-mode operation. High-k thin film HfZrO2 was used for gate insulator of E-mode device to further suppress gate leakage current and enhance device gate operation range. The maximum drain current of E-mode InAlN/GaN MIS-HEMT was 498mA/mm and this value was higher than previous published InAlN/GaN E-mode devices. The measurement results of low-frequency noise also concluded that the low frequency noise is attributed to the mobility fluctuation of the channel and N2O plasma treatment did not increase fluctuation center of gate electrode.