Source/Drain and Contact Engineering for Ge MOSFETs

• Main Authors: Wei-Yo Yuan, 袁瑋佑
• Other Authors: Jiann-Heng Chen
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/69314899495336797347

碩士 === 國立暨南國際大學 === 電機工程學系 === 103 === There are two sections of this thesis. First, we used the monolayer doping to form an ultra shallow junction with no damage on the germanium substrate. Second, we used the low work function metal element, ytterbium, to form the metal germanide. We expected to reduce Fermi level pinning effect by using the high deposition temperature of ytterbium thin film. In the part of monolayer doping, the SIMS profile and diode characteristic was used to examine the shallow junction formation. However, the p type dopant, boron, was hard to diffuse into germanium substrate even after the high temperature annealing. And the n type dopant, phosphorus, could diffuse into the substrate and obtain an ultra shallow (~5nm) junction with the highest doping level 7×1019 cm-3 and no damage. In the part of germanide, we used the high and low thermal budgets of sputtering to examine the ytterbium thin film. The high thermal budget is that the process wafer placed inside the main chamber during the whole process time. The low thermal budget is that the process wafer placed inside the main chamber only at the metal deposition. We find that placing inside the hot chamber for a long time cause the ytterbium film agglomeration. We found that sputtering at room temperature to deposit ytterbium which need RTA 500 ̊C 10s to form Yb3Ge5. But sputtering at high temperature could reduce the RTA temperature to 400 ̊C of forming the ytterbium germanide.