Enhanced Strain Effects in 25-nm Gate-Length Thin-Body nMOSFETs With Silicon–Carbon Source/Drain and Tensile-Stress Liner

摘要

We report the demonstration of 25-nm gate-length $L_{G}$ strained nMOSFETs featuring the silicon–carbon source and drain $( hbox{Si}_{1 - y} hbox{C}_{y} hbox{S/D})$ regions and a thin-body thickness $T_{rm body}$ of $sim$ 18 nm. This is also the smallest reported planar nMOSFET with the $ hbox{Si}_{1 - y} hbox{C}_{y} hbox{S/D}$ stressors. Strain-induced mobility enhancement due to the $hbox{Si}_{1 - y} hbox{C}_{y} hbox{S/D}$ leads to a significant drive-current $I_{rm Dsat}$ enhancement of 52% over the control transistor. Furthermore, the integration of tensile-stress SiN etch stop layer and $hbox{Si}_{1 - y} hbox{C}_{y} hbox{S/D}$ extends the $I_{rm Dsat}$ enhancement to 67%. The performance enhancement was achieved for the devices with similar subthreshold swing and drain-induced barrier lowering. The $hbox{Si}_{1 - y} hbox{C}_{y} hbox{S/D}$ technology and its combination with the existing strained-silicon techniques are promising for the future high-performance CMOS applications.