Development of in-situ Sb-Doped Ge1−xSnx Epitaxial Layers for Source/Drain Stressor of Strained Ge Transistors

摘要

We have investigated the crystalline and electrical characteristics of heavily doped n-type GeSn epitaxial layers with various Sb concentrations up to 10 cm. In this study, we focus the thermal stability of Sb doped GeSn and Ge epitaxial layers and clarify the relationship between the crystalline and electrical characteristics. At the as-grown condition, the substitutional Sb concentration was achieved at higher than 2.6×10 cm. After the post-deposition annealing, Sb-doped GeSn maintained their superior crystallinity up to 400 °C, while the sheet resistance increases with Sb segregation. We also found that Sb atoms doped in the GeSn layer show a higher thermal robustness at 300 °C than those in the Ge layer.