基于原位等离子体氮化及低压化学气相沉积-Si_3N_4栅介质的高性能AlGaN/GaN MIS-HEMTs器件的研究  

High-performance AlGaN/GaN MIS-HEMT device based on in situ plasma nitriding and low power chemical vapor deposition Si_3N_4 gate dielectrics

作　　者：李淑萍[1] 张志利 付凯 于国浩 蔡勇 张宝顺 

机构地区：[1]苏州工业园区服务外包职业学院纳米科技学院,苏州215123 [2]中国科学院大学苏州纳米技术与纳米仿生研究所,苏州215123

出　　处：《物理学报》2017年第19期253-259,共7页Acta Physica Sinica

基　　金：江苏省重点研发计划(批准号:BE2013002-2);国家重点研发计划(批准号:2016YFC0801203);国家重点研发计划重大科学仪器设备开发专项(批准号:2013YQ470767)资助的课题;江苏省重点研究与发展计划(批准号:BE2016084);国家自然科学基金青年科学基金(批准号:11404372)~~

摘　　要：通过对低压化学气相沉积(LPCVD)系统进行改造,实现在沉积Si_3N_4薄膜前的原位等离子体氮化处理,氮等离子体可以有效地降低器件界面处的氧含量和悬挂键,从而获得了较低的LPCVD-Si_3N_4/GaN界面态,通过这种技术制作的MIS-HEMTs器件,在扫描栅压范围V_(G-sweep)=(-30 V,+24 V)时,阈值回滞为186 mV,据我们所知为目前高扫描栅压V_(G+)(>20 V)下的最好结果.动态测试表明,在400 V关态应力下,器件的导通电阻仅仅上升1.36倍(关态到开态的时间间隔为100μs).Gallium nitride （GaN）-based potential applications due to high high electron mobility transistor （HEMT） current density, high switching speed, and power devices have demonstrated great 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/AIGaN/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 p = （-30 V, ＋24 V）, a high breakdown voltage of 881 V, with the substrate grounded. The hysteresis of our device at a

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 

分 类 号：TN386[电子电信—物理电子学]