Current transport mechanisms of InGaN metal-insulator-semiconductor photodetectors

被引：18

作者：

Shao, Z. G. ^{[1
]}

Chen, D. J. ^{[1
]}

Liu, B. ^{[1
]}

Lu, H. ^{[1
]}

Xie, Z. L. ^{[1
]}

Zhang, R. ^{[1
]}

Zheng, Y. D. ^{[1
]}

机构：

[1] Nanjing Univ, Key Lab Adv Photon & Elect Mat, Sch Elect Sci & Engn, Nanjing Natl Lab Microstruct, Nanjing 210093, Peoples R China

来源：

JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B | 2011年 / 29卷 / 05期

关键词：

Atomic layer deposition - Semiconductor alloys - Semiconductor insulator boundaries - Gate dielectrics - Photons - Aluminum oxide - III-V semiconductors - Dielectric materials - Interface states - Metals - MIS devices - Alumina - Plasma CVD - Plasma enhanced chemical vapor deposition;

D O I：

10.1116/1.3622298

中图分类号：

TM [电工技术]; TN [电子技术、通信技术];

学科分类号：

0808 ; 0809 ;

摘要：

The authors report on InGaN metal-insulator-semiconductor (MIS) photodetectors with two different insulating layers of Si3N4 and Al2O3 deposited via plasma-enhanced chemical vapor deposition and atomic layer deposition, respectively. The photoresponse spectra show that the metal-Al2O3-InGaN photodetector exhibits an approximately threefold higher photoelectric responsivity and a larger spectral rejection ratio as compared to the metal-Si3N4-InGaN photodetector at a 1 V reverse bias. The current transport mechanisms in MIS photodetectors were investigated in order to determine the difference in photoresponse. The results show that the space charge limited current is a dominant leakage conduction mechanism in the InGaN MIS photodetectors, but this mechanism is mediated by the exponential trap distribution in the metal-Si3N4-InGaN photodetector. This indicates a higher density of trap states in the Si3N4 bulk. A bidirectional Fowler-Nordheim tunneling effect was observed in the metal-Si3N4-InGaN photodetector, which indicates high trap states in the Si3N4 bulk and the Si3N4-InGaN interface. These traps increase the probability of photogenerated carrier recombination in the bulk of the dielectrics and at the interface of dielectric-InGaN, and hence the photoelectric responsivity is lower. (C) 2011 American Vacuum Society. [DOI: 10.1116/1.3622298]

引用

页数：3