红外与毫米波学报, 2011, 30 (3): 246, 网络出版: 2011-06-14
平面型GaN p-n结探测器的制备与性能
Fabrication and properties of planar GaN pn detector
摘要
采用金属有机物化学气相沉积(MOCVD)方法在蓝宝石衬底上制备了pGaN单晶薄膜.高温(>1100℃)处理及未处理样品的双晶摇摆曲线测试表明高于1150℃会使材料的晶体质量明显变差,这为平面型紫外探测器制备中的部分注入激活条件提供了选择依据.通过TRIM软件优化了注入条件,在选择性注入改型材料上成功制备了平面GaN pn结型光电探测器.测试结果表明:室温下的零偏压暗电流密度为4.7 nA/cm2,而-5 V偏压下的暗电流密度则达到了67 μA/cm2.室温下的峰值响应率0.065 A/W出现在368 nm处.在低温下器件的峰值响应明显降低,80 K时,360 nm处的峰值响应率仅为0.039 A/W.禁带宽度、串联电阻、内建电场等是引起探测器响应率随温度降低的原因.
Abstract
The annealing temperature dependence of FWHM of Xray rocking curves of pGaN layers grown on sapphire substrate by metal organic chemical vapor deposition (MOCVD) were studied. The results show that the quality of pGaN became worse at annealing temperature higher than 1150℃. The implantation conditions were simulated by TRIM. The planar GaN pn detectors were fabricated by Si implantation into pGaN. The currentvoltage (IV) curve at room temperature shows that the dark current density is 4.7nA/cm2 at zero voltage bias. The peak responsivity is 0.065 A/W and 0.039A/W at 368 nm at room temperature and 80 K, respectively. It decreases obviously with the decrease of temperature as a result of the changes in bandgap, series resistance, and buildin potential with temperature.
包西昌, 张文静, 刘诗嘉, 李超, 李向阳. 平面型GaN p-n结探测器的制备与性能[J]. 红外与毫米波学报, 2011, 30(3): 246. BAO XiChang, ZHANG WenJing, LIU ShiJia, LI Chao, LI XiangYang. Fabrication and properties of planar GaN pn detector[J]. Journal of Infrared and Millimeter Waves, 2011, 30(3): 246.