Monolithically integrated enhancement/depletion-mode Al Ga N/Ga N HEMTs SRAM unit and voltage level shifter using fluorine plasma treatment  

作　　者：陈永和 郑雪峰 张进城 马晓华 郝跃 

机构地区：[1]Key Laboratory for Wide Band-Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University [2]School of Advanced Materials and Nanotechnology, Xidian University

出　　处：《Journal of Semiconductors》2016年第5期78-83,共6页半导体学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(No.61334002);the Opening Project of Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory(No.ZHD201206);the Program for New Century Excellent Talents in University(No.NCET-12-0915)

摘　　要：A GaN-based E/D mode direct-couple logic 6 transistors SRAM unit and a voltage level shifter were designed and fabricated. E-mode and D-mode A1GaN/GaN HEMTs were integrated in one wafer using fluorine plasma treatment and using a moderate A1GaN barrier layer heterojunction structure. The 6 transistors SRAM unit consists of two symmetrical E/D mode inverters and two E-mode switch HEMTs. The output low and high voltage of the SRAM unit are 0.95 and 0.07 V at a voltage supply of 1 V. The voltage level shifter lowers the supply voltage using four Ni-A1GaN Schottky diodes in a series at a positive supply voltage of 6 V and a negative supply voltage of-6 V. By controlling the states of inverter modules of the level shifter in turn, the level shifter offers two channel voltage outputs of-0.5 and-5 V. The flip voltage of the level shifter is 0.76 V. Both the SRAM unit and voltage shifter operate correctly, demonstrating the promising potential for GaN-based E/D mode digital and analog integrated circuits. Several considerations are proposed to avoid the influence of threshold voltage degradation of D-mode and E-mode HEMT on the operation of the circuit.A GaN-based E/D mode direct-couple logic 6 transistors SRAM unit and a voltage level shifter were designed and fabricated. E-mode and D-mode A1GaN/GaN HEMTs were integrated in one wafer using fluorine plasma treatment and using a moderate A1GaN barrier layer heterojunction structure. The 6 transistors SRAM unit consists of two symmetrical E/D mode inverters and two E-mode switch HEMTs. The output low and high voltage of the SRAM unit are 0.95 and 0.07 V at a voltage supply of 1 V. The voltage level shifter lowers the supply voltage using four Ni-A1GaN Schottky diodes in a series at a positive supply voltage of 6 V and a negative supply voltage of-6 V. By controlling the states of inverter modules of the level shifter in turn, the level shifter offers two channel voltage outputs of-0.5 and-5 V. The flip voltage of the level shifter is 0.76 V. Both the SRAM unit and voltage shifter operate correctly, demonstrating the promising potential for GaN-based E/D mode digital and analog integrated circuits. Several considerations are proposed to avoid the influence of threshold voltage degradation of D-mode and E-mode HEMT on the operation of the circuit.

关 键 词：AlGaN/GaN E/D mode SRAM voltage level shifter 

分 类 号：TN386[电子电信—物理电子学] TP333[自动化与计算机技术—计算机系统结构]