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...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.展开更多
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)
文摘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.
