物理学报2016，Vol.65Issue(3)：038501-1-038501-6,6.DOI:10.7498/aps.65.038501
AlGaN/GaN双异质结F注入增强型高电子迁移率晶体管∗
Enhancement mo de AlGaN/GaN double heterostructure high electron mobility transistor with F plasma treatment
摘要
Abstract
Effects of double heterostructure materials (AlGaN/GaN/AlGaN/GaN) with different GaN channel thickness values (14 nm, 28 nm, 60 nm) on the high electron mobility transistor (HEMT) are simulated by using silvaco, and furthermore, the differences in characteristic among the enhancement mode devices made from such double heterostructure materials with different F injection doses (150 W, 135 W) are also simulated. The simulation results show that the threshold voltage shifts towards positive direction and the saturation current decreases as the GaN channel thickness decreases. The two-dimensional electron gas (2 DEG) density could be reduced as GaN channel thickness decreases due to piezoelectric polarization weakened by backing AlGaN barrier. Combining F plasma treatment and double heterostructure material, the enhancement mode device with high positive threshold voltage is successfully developed. The DC characteristics of the enhancement mode devices with different GaN channel thickness values are analyzed comparatively, and the simulation results are validated by using the experimental results. The threshold voltages of these enhancement mode devices with GaN channel thickness values of 14 nm, 28 nm, and 60 nm reach 1.1 V, 0.8 V, and 0.3 V, respectively. The maximum transconductance values of these enhancement mode devices with GaN channel thickness values of 14 nm, 28 nm, and 60 nm reach 115 mS/mm, 137 mS/mm, and 198 mS/mm, respectively. The thinner GaN channel thickness in the double heterostructure could reduce the depth of quantum well and 2 DEG density, so that the device with a GaN channel thickness of 14 cm has a lower saturation current. The breakdown voltages and gate reverse leakage currents of the three kinds of devices are investigated, and the device with a thinner GaN channel has a lower leakage current and higher breakdown voltage due to weakened vertical electrical field in thinner channel double heterostructure. The damage of channel mobility in F plasma treatment is weakened by using a lower plasma power (135 W), and the enhancement mode device without annealing process demonstrates a better saturation current and transconductance characteristic. The results of the device with annealing confirm that the plasma damage is depressed at an F injection power of 135 W. The threshold voltage temperature stability of 14 nm GaN channel thickness device is studied, and∆Vth is only 0.4 V after 350 ◦C 2 min annealing process. Drain induced barrier lowering (DIBL) effects of the HEMTs with double heterostructures are investigated, and the DIBL value of the14 nm GaN channel device is 16 mV/V. The DIBL value indicates a good limiting property of the 2 DEG in double heterostructure device.关键词
双异质结/增强型器件/F等离子体/漏致势垒降低效应Key words
double heterostructure/enhancement mode device/F plasma/drain induced barrier lowering effect引用本文复制引用
王冲,郝跃,赵梦荻,裴九清,何云龙,李祥东,郑雪峰,毛维,马晓华,张进成..AlGaN/GaN双异质结F注入增强型高电子迁移率晶体管∗[J].物理学报,2016,65(3):038501-1-038501-6,6.基金项目
国家自然科学基金(批准号:61574110,61574112,61106106)资助的课题.* Project supported by the National Natural Science Foundation of China (Grant Nos.61574110,61574112,61106106) （批准号:61574110,61574112,61106106）
