Simulation of the effects of defects in low temperature Ge buffer layer on dark current of Si-based Ge photodiodes*Project supported by the Key Project of Natural Science Foundation of China (No. 61534005), the National Science Foundation of China (No. 61474081), the National Basic Research Program of China (No. 2013CB632103), the Natural Science Foundation of Fujian Province (No. 2015D020), and the Science and Technology Project of Xiamen City (No. 3502Z20154091). (April 2017)

• Record Type: Journal Article
• Authors: Yi, Xiaohui; Huang, Zhiwei; Lin, Guangyang; Li, Cheng; Chen, Songyan; Huang, Wei; Li, Jun; Wang, Jianyuan
• Is Part Of: Journal of semiconductors. Volume 38:Number 4(2017:Apr.)
• Publication Date: 2017-04
• Subjects: germanium -- photodiodes -- defects -- dark current -- simulation; 4250; Semiconductors -- Periodicals; 621.38152
• DOI: 10.1088/1674-4926/38/4/042001
• Languages: English
• ISSNs: 1674-4926

Abstract

Abstract: The influence of defects in low temperature Ge layer on electrical characteristics of p-Ge/i-Ge/n-Si and n-Ge/i-Ge/p-Ge photodiodes (PDs) was studied. Due to a two-step growth method, there are high defect densities in low-temperature buffer Ge layer. It is shown that the defects in low-temperature Ge layer change the band diagrams and the distribution of electric field, leading to the increase of the total dark current for p-Ge/i-Ge/n-Si PDs, whereas these defects have no influence on the dark current for n-Ge/i-Ge/p-Ge PDs. As a complement, a three-dimensional simulation of the total current under illumination was also performed.