具有高阈值电压和超低栅漏电的400 V常关型槽栅AlGaN/GaN金属氧化物半导体高电子迁移率晶体管

摘要

We report normally-off operation of an AlGaN/GaN recessed MOS-gate high electron mobility transistor (MOS-gate HEMT) on Si (111) substrate fabricated with the inductively coupled plasma (ICP) recessed technique. By employing a 40nm thick Al2O3gate dielectric deposited by atomic layer deposition (ALD), the AlGaN/GaN HEMT with a gate length of 2 μm and a gate width of 10.35 mm exhibits a high threshold voltage of + 4.3 V, a specific on-resistance of 5.73 m?·cm2and a saturation drain current of 0.71 A. When the gate bias (Vgs) is 0V, the breakdown voltage (BV) of the AlGaN/GaN HEMT is 400 V and the drain to source leakage current is below 320 μA with a gate-drain distance of 10μm. The on/off drain current ratio (ION/IOFF) is over 109. Under a negative gate bias (Vgs) of - 20V, the gate to source leakage current is as low as 1.8 nA. Under a positive gate bias (Vgs) of +12 V, the gate to source leakage current is only 1.6 μA. The high ION/IOFFratio and low gate to source leakage both indicate high quality of the Al2O3/GaN interface.%介绍了一种采用 ICP 干法刻蚀技术制备的槽栅常关型 AlGaN/GaN 金属氧化物半导体高电子迁移率晶体管(MOS-HEMT).采用原子层淀积(ALD)实现40 nm 的 Al2O3栅介质的沉积.槽栅常关型AlGaN/GaN MOS-HEMT的阈值电压为+4.3 V.在栅压Vgs=+10 V时,槽栅常关型AlGaN/GaN MOS-HEMT饱和电流为0.71 A,特征导通电阻为5.73 m?· cm2.在栅压Vgs=0 V时,器件的击穿电压为400 V,关断漏电流为320 μA.器件的开启与关断电流比超过了109.在栅压为-20 V时,槽栅常关型AlGaN/GaN MOS-HEMT的栅漏电流为1.8 nA.高的开启与关断电流比和低的栅漏电流反映了Al2O3/GaN界面具有很好的质量.