Study On The Theraml Stability Of NiGe/n-Ge Schottky Junction And Defects Behaviors Of The GeO₂/Ge Gate Stacks

While the CMOS technology is developing rapidly thanks to the improvement of the Metal-Oxide-Semiconductor Field-Effect Transistors?MOSFETs?,it becomes increasingly difficult to continue enhancing the performance of CMOS intergrated circuits through device scaling down.There are several challenges to the further development of conventional Si MOSFETs as their physical dimensions have come to the nm-scale,such as the short-channel effect,the large Source/Drain parasitic resistance and the reliability.In order to overcome these obstacles,the application of high mobility channel materials is considered as one of possible solutions.Due to the high mobility of both electron and hole,Ge is regarded as a promising channel material.Recently,high performance Ge MOSFETs have been demonstrated,with hole mobility over 500 cm²/Vs and electron mobility over 1000 cm²/Vs.However,there are still several challenges for the practical application of Ge MOSFETs,including the large Source/Drain parasitic resistance and the poor reliability of Ge gate stacks.In this study,the research toward advanced Ge MOSFETs is divided into two sections.In the second section,the high performance Ni Ge/n-Ge Source/Drain Ge p MOSFETs were fabricated with dopant segregation,and the thermal stability was improved for the Ni Ge/n-Ge Ge Schottky junctions with dopant segregation.In the third section,the impact of electrical stress on the defect generation in thin Ge O₂/Ge gate stacks was studied,and it is found that the Ge O₂/Ge MOS interface exhibits relatively high defect generation rates.These results are informative as a guideline to further improve the Ge MOSFETs performance for future CMOS technology.