1. Surface nitridation for improved dielectric/III-nitride interfaces in GaN MIS-HEMTs.
- Author
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Chen, Kevin J., Yang, Shu, Tang, Zhikai, Huang, Sen, Lu, Yunyou, Jiang, Qimeng, Liu, Shenghou, Liu, Cheng, and Li, Baikui
- Subjects
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NITRIDATION , *CHEMICAL reactions , *GALLIUM nitride , *HETEROSTRUCTURES , *HETEROJUNCTIONS - Abstract
Effective interface engineering techniques in III-nitride heterojunction power devices, aiming at yielding high VTH stability in insulated-gate devices and suppressed current collapse in high-voltage switching operation, are of critical significance to enhance device performance and reliability. In this work, we present an interface enhancement technology featuring in situ low-damage NH3/Ar/N2 pre-gate plasma treatment prior to the ALD-Al2O3 deposition for high-performance III-nitride MIS-HEMTs. It is manifest that this technology can effectively remove the native oxide while forming a monocrystal-like nitridation interfacial-layer (NIL) on the III-nitride surface. The Al2O3(NIL)/GaN/AlGaN/GaN MIS-heterostructures with high-quality interface exhibit well-behaved electrical characteristics, including a small subthreshold swing of ∼64 mV/dec, a small hysteresis of ∼0.09 V, tiny f/T dispersions in the C- V characteristics, and low interface trap density of ∼1 × 1012-6 × 1012 cm−2eV−1. Cross-sectional TEM micrograph of the Al2O3/III-nitride gate stack with a monocrystal-like nitridation interfacial-layer (NIL). [ABSTRACT FROM AUTHOR]
- Published
- 2015
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