Small Vth Shift and Low Dynamic Ron in GaN MOSHEMT With ZrO2 Gate Dielectric

• Published in: IEEE transactions on electron devices 2023-11, Vol.70 (11), p.5590-5595
• Main Authors: Zhang, Yu, Gu, Yitian, Chen, Jiaxiang, Zhu, Yitai, Chen, Baile, Jiang, Huaxing, Lau, Kei May, Zou, Xinbo
• Format: Article
• Language: English
• Subjects: Dielectrics; Dynamic ON-resistance (Rno); GaN; HEMTs; Logic gates; metal–oxide–semiconductor high–electron mobility transistor (MOSHEMT); MODFETs; Stress measurement; Threshold voltage; threshold voltage (Vth) instability; Transient analysis; ZrO2 dielectric
• ISSN: 0018-9383
• DOI: 10.1109/TED.2023.3313999

The OFF-state stress-induced threshold voltage ( {V}_{\text {th}} ) instability and dynamic ON-resistance ( {R}_{ \mathrm{\scriptscriptstyle ON}} ) of GaN metal-oxide-semiconductor high-electron mobility transistor (MOSHEMT) with ZrO2 gate dielectric are thoroughly investigated. Upon negative gate bias stressing, a small threshold voltage shift of −0.31 V is observed and the deviation is attributed to the emission of electrons at the ZrO2/AlGaN interface. An emission activation energy of 0.28 eV and a capture activation energy of 0.30 eV are extracted by threshold voltage transient spectroscopy performed at various temperatures. When the device is exposed to OFF-state drain-source bias stressing, the drain current is found to decrease despite negative shift of {V}_{\text {th}} . A low dynamic {R}_{ \mathrm{\scriptscriptstyle ON}} of 2.05 is obtained by time-resolved measurements, given a 50-V drain voltage stressing for a duration of 100 s. The decrease in forward conductance is related to the capture of electrons in the access region, with a capture activation energy of 0.18 eV revealed by temperature-dependent drain current transient (DCT) analysis. The results indicate that high-quality ZrO2 represents an attractive high- {k} gate dielectric option for GaN MOSHEMTs in power switching electronics.