关键词: 氮化镓高电子迁移率晶体管/
低压化学气相沉积/
原位氮化
English Abstract
High-performance AlGaN/GaN MIS-HEMT device based on in situ plasma nitriding and low power chemical vapor deposition Si3N4 gate dielectrics
Li Shu-Ping1,Zhang Zhi-Li2,
Fu Kai2,
Yu Guo-Hao2,
Cai Yong2,
Zhang Bao-Shun2
1.Suzhou Industrial Park Institute of Services Outsourcing, Suzhou 215123, China;
2.Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou 215123, China}
Fund Project:Project supported by the Key Technologies Support Program of Jiangsu Province, China (Grant No. BE2013002-2), The National Key Research and Development Program of China (Grant No. 2016YFC0801203), the Key Research and Development Program of Jiangsu Province, China (Grant No. BE2016084), the National Natural Science Foundation of China (Grant No. 11404372), and the National Key Scientific Instrument and Equipment Development Projects of China (Grant No. 2013YQ470767).Received Date:24 April 2017
Accepted Date:10 July 2017
Published Online:05 October 2017
Abstract:Gallium nitride (GaN)-based high electron mobility transistor (HEMT) power devices have demonstrated great potential applications due to high current density, high switching speed, and low ON-resistance in comparison to the established silicon (Si)-based semiconductor devices. These superior characteristics make GaN HEMT a promising candidate for next-generation power converters. Many of the early GaN HEMTs are devices with Schottky gate, which suffer a high gate leakage and a small gate swing. By inserting an insulator under gate metal, the MIS-HEMT is highly preferred over the Schottky-gate HEMT for high-voltage power switche, owing to the suppressed gate leakage and enlarged gate swing. However, the insertion of the gate dielectric creates an additional dielectric/(Al) GaN interface that presents some great challenges to AlGaN/GaN MIS-HEMT, such as the threshold voltage (Vth) hysteresis, current collapse and the reliability of the devices. It has been reported that the poor-quality native oxide (GaOx) is detrimental to the dielectric/(Al) GaN interface quality that accounted for the Vth instability issue in the GaN based device. Meanwhile, it has been proved that in-situ plasma pretreatment is capable of removing the surface native oxide. On the other hand, low power chemical vapor deposition (LPCVD)-Si3N4 with free of plasma-induced damage, high film quality, and high thermal stability, shows great potential applications and advantages as a choice for the GaN MIS-HEMTs gate dielectric and the passivation layer. In this work, an in-situ pre-deposition plasma nitridation process is adopted to remove the native oxide and reduce surface dangling bonds prior to LPCVD-Si3N4 deposition. The LPCVD-Si3N4/GaN/AlGaN/GaN MIS-HEMT with a high-quality LPCVD-Si3N4/GaN interface is demonstrated. The fabricated MIS-HEMT exhibits a very-low Vth hysteresis of 186 mV at VG-sweep=(-30 V, +24 V), a high breakdown voltage of 881 V, with the substrate grounded. The hysteresis of our device at a higher positive end of gate sweep voltage (VG +20 V) is the best to our knowledge. Switched off after an off-state VDS stress of 400 V, the device has a dynamic on-resistance Ron only 36% larger than the static Ron.
Keywords: GaN-based high electron mobility transistor/
low pressure chemical vapor deposition/
in-situ pre-deposition plasma nitridation
