器件结构对Al0．3Ga0．7N Schottky探测器性能的影响

Effects of Structure on Performances of Al_(0.3)Ga_(0.7)N Schottky Ultraviolet Detectors

在利用金属有机化学气相沉积(MOCVD)方法生长的Al0.3Ga0.7N材料上制备了平面和台面结构的肖特基探测器。I-V和光谱响应测试结果表明:台面结构器件的反向漏电流大于平面结构器件的反向漏电流,它们的势垒高度分别为0.71 eV和0.90 eV,理想因子分别为1.12和1.02;峰值响应率分别为0.07 A/W和0.005 A/W,台面结构器件的响应光谱曲线在响应波段比较平坦,而平面结构器件的光谱响应是一条随着波长的减小而降低的曲线。这些现象可能主要是由于台面结构的欧姆接触电阻及串联电阻相对较小和离子束刻蚀对台面结构所带来的损伤所致。

Both lateral and mesa structure Schottky detectors were fabricated on Al0.3 Ga0.7 N materials grown by metalorganic chemical vapor deposition（MOCVD）. Measurement results of the I-V and spectral response show that the dark current of the mesa device is larger than that of the lateral one,their barrier heights are 0.71 eV and 0.90 eV, the ideality factors are 1.12 and 1.02, the peak responsivities are 0.07 A/W and 0. 005 A/W, respectively. The spectral reponse curve of the mesa strcture Schottky is flat when the light wavelength is smaller than the cutoff wavelength, but that of the lateral one is tortuous and the value decreases when the light wavelength becomes shorter. The phenomena are attributed to the fact that the contact and sereial resistence of the mase is smaller than that of the lateral and the damage on the mase stracture Schottky detectors introduced by ion beam etching.