Interface charge engineering on an in situ SiNx/AlGaN/GaN platform for normally off GaN MIS-HEMTs with improved breakdown performance.
- Resource Type
- Article
- Authors
- He, JiaQi; Wen, KangYao; Wang, PeiRan; He, MingHao; Du, FangZhou; Jiang, Yang; Tang, ChuYing; Tao, Nick; Wang, Qing; Li, Gang; Yu, HongYu
- Source
- Applied Physics Letters. 9/4/2023, Vol. 123 Issue 10, p1-5. 5p.
- Subject
- *BREAKDOWN voltage
*MODULATION-doped field-effect transistors
*GALLIUM nitride
*ATOMIC layer deposition
*THRESHOLD voltage
*ENGINEERING
- Language
- ISSN
- 0003-6951
This work adopts interface charge engineering to fabricate normally off metal–insulator–semiconductor high electron mobility transistors (MIS-HEMTs) on an in situ SiNx/AlGaN/GaN platform using an in situ O3 treatment performed in the atomic layer deposition system. The combination of in situ SiNx passivation and an O3-treated Al2O3/AlGaN gate interface allows the device to provide an excellent breakdown voltage of 1498 V at a low specific on-resistance of 2.02 mΩ cm2. The threshold voltage is increased by 2 V by significantly compensating the net polarization charges by more than five times with O3 treatment as well as reducing the interface traps and improving the high-temperature gate stability. Furthermore, a physical model of fixed charges at the Al2O3/AlGaN interface is established based on dielectric thickness-dependent linear fitting and numerical calculations. The matched device performance and simulated energy band bending elucidate the O3-treated fixed-charge modulation mechanism, providing a practical method for producing normally off GaN MIS-HEMTs. [ABSTRACT FROM AUTHOR]