Charge Trapping Layer Enabled Normally-Off β-Ga2O3 MOSFET

• Published in: IEEE transactions on electron devices Vol. 70; no. 6; pp. 3191 - 3195
• Main Authors: He, Minghao, Wen, Kangyao, Deng, Chenkai, Li, Mujun, Cui, Yifan, Wang, Qing, Yu, Hongyu, Ang, Kah-Wee
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.06.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aluminum oxide; Charge trapping layer (CTL); Degradation; Dielectrics; E-mode; Gallium oxides; Ga₂O; Hafnium oxide; Logic gates; Microelectronics; MOSFET; MOSFETs; Temperature measurement; Trapping
• ISSN: 0018-9383; 1557-9646
• DOI: 10.1109/TED.2023.3267758

In this work, a normally-OFF <inline-formula> <tex-math notation="LaTeX">\beta </tex-math></inline-formula>-Ga2O3 MOSFET enabled by charge trapping layer (CTL) is demonstrated for the first time. The CTL consists of Al:HfO<inline-formula> <tex-math notation="LaTeX">_{x} 1 </tex-math></inline-formula>:5 and the tunneling barrier (TB) is Al2O3/HfOx/Al2O3 stack. The developed Ga2O3 MOSFET exhibits a wide <inline-formula> <tex-math notation="LaTeX">{V}_{\text {th}} </tex-math></inline-formula> tuning range to normally-OFF operation and a long-lasting retention characteristic of −0.3 V (ten years). The device obtains a breakdown voltage (BV) of 1815 V, showing high reverse blocking capability based on the proposed CTL technique. <inline-formula> <tex-math notation="LaTeX">{I} </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">{V} </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">{C} </tex-math></inline-formula>-<inline-formula> <tex-math notation="LaTeX">{V} </tex-math></inline-formula> analyses are carried out under various temperatures to study the mechanism and explore the charge trapping and de-trapping processes. The results indicate a promising method to achieve E-mode operation for Ga2O3 MOSFET with low charge loss and stable <inline-formula> <tex-math notation="LaTeX">{V}_{\text {th}} </tex-math></inline-formula>.