Design, fabrication, and analysis of SiGeC heterojunction PMOSFETs

We present the evaluation of the strain-stabilizing capabilities of C in the Si1-xGex system. To demonstrate these effects, we have designed Si1-x-yGexCy heterojunction PMOSFET devices over a range of Ge concentrations, with thicknesses that would typically result in relaxed or metastable films under normal processing conditions. The de characteristics of Si1-x-yGexCy, SiGe, and Si PMOSFETs (L = 10 mu m) were evaluated at room temperature and at 77 K, In general, the saturation mobility in Si1-x-yGexCy devices is higher than that of Si1-xGex and Si devices at low gate bias and room temperature. This enhancement is attributed to the strain stabilization effect of C, With proper optimization of Ge and C concentrations, it is possible to fabricate devices with significant improvements in drive current under normal operating conditions (0-3 V, 300K), This application of Si1-x-yGexCy in PMOSFETs demonstrates the potential benefits of using of C in the Column IV heterostructure system.