Selective Growth of B- and C-doped SiGe Layers in Unprocessed and Recessed Si Openings for pMOSFET Application

This work presents pattern dependency of selective epitaxial growth of boron- or carbon-doped SiGe layers in recessed or unprocessed openings. The layer profile and quality of epi-layers were found to be dependent on chip layout and the growth parameters. Carbon- and boron-doping compensated the strain in SiGe layers and when both dopants are introduced the strain reduction was additive. The incorporation of boron and carbon in SiGe matrix showed to be a competitive action. The concentration of carbon decreased when the boron amount increased in SiGe layers with higher Ge content.