大电流(直流)冲击试验对-族氮化物异质结深电子态的影响

Deep Electron States Generation in Ⅲ\|Ⅴ Nitride Heterojunctions Due to High DC Current Stressing

利用电流电压（ Ｉ Ｖ）、电致发光（ Ｅ Ｌ）和深能级瞬态傅里叶谱（ Ｄ Ｌ Ｔ Ｆ Ｓ）技术研究ⅢⅤ族氮化物基异质结深电子态．观察到大电流（直流）冲击引起电流电压和电致发光特性的弛豫． Ｄ Ｌ Ｔ Ｆ Ｓ研究表明，电流冲击之前，样品存在一个位于导带下 １１ｅ Ｖ 处深能级（ Ｅ１），它具有 ２７×１０１３ ｃｍ － ３ 浓度和 ５×１０－ １４ ｃｍ ２ 俘获截面．经电流冲击（７７ Ｋ，２００ｍ Ａ 和 ４０ｍ ｉｎ）后， Ｅ１ 浓度为４２１×１０１３ｃｍ － ３ ，约增加了 ２ 倍．实验结果表明 Ｅ１ 浓度的增加与样品 Ｉ Ｖ、 Ｅ Ｌ

Deep levels generation in Ⅲ\|Ⅴ nitride based heterojunctions as a result of high current stressing is studied by Deep Level Transient Fourier Spectroscopy (DLTFS) technique. The DLTFS experiments are conducted from 77 to 500K. The devices are stressed using DC currents between 100mA and 200mA. Significant degradation in the I\|V characteristics and the electroluminescence are observed. Our studies show that prior to the DC stressing a deep level, El, is detected at 1.1eV below E \-c with a concentration of 2.7×10 13 cm -3 and a capture cross section of 5×10 -14 cm\+2. Subsequent to high DC current stressing at 200mA, the concentration of El is seen to increase to 4.21×10 13 cm -3 . The increase in the concentration of the deep level is believed to play a role in the degradation in the I\|V and electroluminescence characteristics.