标准氟离子注入实现增强型GaN基功率器件

Enhancement-Mode GaN-Based Power Devices Fabricated by Using Standard Fluorine Ion Implantation

介绍了一种直接利用离子注入机对AlGaN/GaN高电子迁移率晶体管(HEMT)器件的栅下进行氟(F)离子注入的方法,成功实现了增强型HEMT器件,阈值电压从耗尽型器件的-2.6 V移动到增强型器件的+1.9 V。研究了注入剂量对器件性能的影响,研究发现随着注入剂量的不断增加,阈值电压不断地正向移动,但由于存在高能F离子的注入损伤,器件的正向栅极漏电随着注入剂量的增加而不断上升,阈值电压正向移动也趋于饱和。因此,提出采用在AlGaN/GaN异质结表面沉积栅介质充当能量吸收层,降低离子注入过程中的损伤,成功实现了阈值电压为+3.3 V,饱和电流密度约为200 mA/mm,同时具有一个较高的开关比109的增强型金属-绝缘层-半导体HEMT(MIS-HEMT)器件。

A method for directly implanting F ions into the gate of the AlGaN/GaN high electron mobility transistor（ HEMT） device by ion implanter was introduced. An enhancement-mode（ E-mode）HEMT device was successfully fabricated and the threshold voltage of the depletion-mode（ D-mode） of-2. 6 V shifted to the E-mode of ＋1. 9 V. The effects of implantation dose on device performances were studied. It is found that threshold voltage is continuously moving toward positive values with the increasing of ion implantation dose. However,due to the implantation damage of high energy F ions,the forward gate leakage of the device increases with the increasing of implantation dose,and the threshold voltage moves forward and tends to saturation. Therefore,the method of deposition the gate dielectric on the AlGaN/GaN heterojunction surface as an energy absorption layer was proposed to reduce the damage during ion implantation. The E-mode metal-insulator-semiconductor HEMT（ MIS-HEMT） with the threshold voltage of ＋3. 3 V,the saturation current density of about 200 mA/mm and a higher switching ratio of 109 was fabricated.