Development and characteristic analysis of a field-plated Al2O3/AlInN/GaN MOS-HEMT

• Published in: Chinese physics B Vol. 20; no. 1; pp. 8 - 12
• Main Author: 毛维 杨翠 郝跃 张进成 刘红侠 毕志伟 许晟瑞 薛军帅 马晓华 王冲 杨林安 张金风 匡贤伟
• Format: Journal Article
• Language: English
• Published: IOP Publishing 2011
• Subjects: HEMT器件; MOS; 原子层沉积; 器件特性; 氧化铝; 超薄栅介质; 高功率微波技术
• ISSN: 1674-1056; 2058-3834
• DOI: 10.1088/1674-1056/20/1/017203

We present an AIInN/AlN/GaN MOS-HEMT with a 3 nm ultra-thin atomic layer deposition （ALD） Al2O3 dielectric layer and a 0.3 μm field-plate （FP）-MOS-HEMT. Compared with a conventional AIInN/AlN/GaN HEMT （HEMT） with the same dimensions, a FP-MOS-HEMT with a 0.6 μm gate length exhibits an improved maximum drain current of 1141 mA/mm, an improved peak extrinsic transconductance of 325 mS/mm and effective suppression of gate leakage in both the reverse direction （by about one order of magnitude） and the forward direction （by more than two orders of magnitude）. Moreover, the peak extrinsic transconductance of the FP-MOS-HEMT is slightly larger than that of the HEMT, indicating an exciting improvement of transconductance performance. The sharp transition from depletion to accumulation in the capacitance-voltage （C-V） curve of the FP-MOS-HEMT demonstrates a high-quality interface of Al2O3/AlInN. In addition, a large off-state breakdown voltage of 133 V, a high field-plate efficiency of 170V/#m and a negligible double-pulse current collapse is achieved in the FP-MOS-HEMT. This is attributed to the adoption of an ultra-thin Al2O3 gate dielectric and also of a field-plate on the dielectric of an appropriate thickness. The results show a great potential application of the ultra-thin ALD-Al2O3 FP-MOS-HEMT to deliver high currents and power densities in high power microwave technologies.