Effects on selective epitaxial growth of strained-SiGe p-MOSFETs on various (001) Si recess structures

Influences of source and drain recess structures on SiGe epitaxy growth, SiGe step height, facet formation, I_D,sat and resistance performance are investigated. Growth rate of SiGe height increases with decreased recess width at a fixed depth of 62 nm. Under a fixed recess width of 96.3 nm, the deeper the recess, the higher the growth rate of SiGe height. An increase in the depth/width ratio of the recessed Si geometry may promote SiGe {001} growth. Upon the recess, SiGe step height is influenced by the initial SiGe orientation. A longer {001} facet of SiGe initial orientation causes a higher growth rate of SiGe step height. Higher I_Dsat and lower resistance can be achieved by increasing SiGe volume with wider recess width, deeper recess depth, and higher SiGe step height.