AlGaN/GaN MOS-HEMTs With Gate ZnO Dielectric Layer

作者：Lee Ching Ting^*; Chiou Ya Lan; Lee Chi Sen

来源：IEEE Electron Device Letters, 2010, 31(11): 1220-1223.

DOI：10.1109/LED.2010.2066543

• AlGaN/GaN metal-oxide-semiconductor HEMTs (MOS-HEMTs)
• high-frequency performance
• low-frequency noise
• vapor cooling condensation system
• zinc oxide (ZnO) insulator films

The vapor cooling condensation system is used to grow ZnO insulator films of low carrier concentration and high resistivity as the gate dielectrics for AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS-HEMTs). The saturation drain-source current and the maximum extrinsic transconductance are measured as 0.61 A/mm and 153 mS/mm, respectively. The gate leakage currents, determined with the forward gate bias of V(GS) = 3.5 V and the reverse gate bias of V(GS) = -12 V, applied are 1.21 x 10(-4) A/mm and 7.16 x 10(-6) A/mm, respectively. The unit gain cutoff frequency and maximum frequency of the oscillation are also measured as 7.2 and 11.5 GHz, respectively. The low-frequency noise obtained is well fitted with a 1/f function in the linear region. Hooge's coefficient a is extracted as 9.74 x 10(-5) when the MOS-HEMTs operate at 100 Hz and V(GS) = -4 V. The current recoveries of the gate and drain lags are determined to be 61% and 47% for the MOS-HEMTs, respectively.

• 出版日期2010-11