Investigation of Raised Germanium p+-n Junction Structures

• Main Authors: Min-Ching Chu, 朱銘清
• Other Authors: Wen-Luh Yang
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/46305649568788742885

碩士 === 逢甲大學 === 電子工程所 === 95 === This thesis is divided into two parts to present my experimental results. Firstly, we use raised structures with different materials including Si, SiGe and Ge in diodes by selective epitaxial growth. We find that the use of pure Ge for raised structure will cause serious leakage current density. The effect of threading dislocations in junction depletion region contributes to the area leakage component. The area leakage current density for Ge sample is about 1.35E-3 A/cm2 at -1V. In addition, we propose some process recipes for the raised structure to identify the decisive parameter for current-voltage fluctuation. According to the prediction form experimental results, temperature of Silicide process will seriously impact the leakage current density. 500℃ at 30sec for silicide process temperature will increase the leakage current about 2 orders of magnitude. However, 400℃ sample treatment only increases the leakage current to 1 order of magnitude. Furthermore, using UHVCVD systems to deposit germanium films will lead to deep depth of boron diffusion effect. We fabricate a new stack structure to minimize deep junction depth, but only a slight increase of leakage current.