p-Channel GaN Transistor Based on p-GaN/AlGaN/GaN on Si

• Published in: IEEE electron device letters 2019-07, Vol.40 (7), p.1036-1039
• Main Authors: Chowdhury, Nadim, Lemettinen, Jori, Xie, Qingyun, Zhang, Yuhao, Rajput, Nitul S., Xiang, Peng, Cheng, Kai, Suihkonen, Sami, Then, Han Wui, Palacios, Tomas
• Format: Article
• Language: English
• Subjects: AlGaN; Aluminum gallium nitride; Aluminum gallium nitrides; CMOS; Contact resistance; Electron gas; Gallium nitride; Gallium nitrides; GaN; Heterostructures; Logic gates; Metalorganic chemical vapor deposition; MISFET; Ohmic contacts; Organic chemistry; p-channel; Resistance; Semiconductor devices; Silicon substrates; Substrates; Transistors
• ISSN: 0741-3106; 1558-0563
• DOI: 10.1109/LED.2019.2916253

In this letter, we demonstrate a recessed-gate p-channel MISFET using a p-GaN (70 nm)/Al 0.2 Ga 0.8 N (15 nm)/GaN heterostructure grown by metalorganic chemical vapor deposition (MOCVD) on a Si substrate. A major benefit of such epi-structure is that it contains both a 2-dimensional electron gas (2-DEG) and a 2-dimensional hole gas (2-DHG), hence making it suitable for the GaN-based complementary circuit implementation. In addition, the 2-DEG at the interface of the AlGaN/GaN heterostructure is depleted due to the p-GaN layer on top giving rise to normally- OFF operation for the n-channel transistors. A contact resistivity of \textsf {4.9}\times \textsf {10}^{-\textsf {6}}\Omega \cdot \textsf {cm}^{\textsf {2}} is obtained for the ohmic contact to the hole channel for a p-GaN Mg concentration of \textsf {2}\times \textsf {10}^{\textsf {20}}\, \textsf {cm}^{-\textsf {3}} . Long channel ( {L} _{\textsf {g}}=\textsf {3}\,\,{\boldsymbol \mu } \text{m} and {L} _{\textsf {sd}}=\textsf {9}\,\,{\boldsymbol \mu } \text{m} ) p-type transistors show an ON-OFF current ratio of ~10 5 and ON resistance of \sim 2.3~\text{k}{\Omega } \cdot \textsf {mm} at {V} _{\textsf {GS}}=-\textsf {11} V.