In this chapter, a brief discussion on the nature of point defect-mediated diffusion, boron diffusion in silicon and SiGe, and reasons for strain relaxation in SiGe has been made. Because of the relationship between dopant diffusion and point defect diffusion.both the movement of point defects and dopants need to be modelled simultaneously. It has been shown that boron in strained, low Ge-composition SiGe layers diffuses primarily via an interstitial mediated mechanism. Mobile misfit dislocations can act as a strong interstitial sink but immobile dislocations appear to have very little effect on the point defect population. However, experiments should be performed to determine the segregation coefficient across the Si/SiGe interface as a function of germanium and dopant concentration. Further studies should also be taken up to find more closely the relationship between relaxation and interstitial absorption.

Inspec keywords: Ge-Si alloys; germanium; semiconductor doping; boron

Other keywords: boron diffusion; dopant concentration; interstitial absorption; interstitial mediated mechanism; strain relaxation; point defect-mediated diffusion; dopant diffusion; SiGeC film; germanium; SiGe film

Subjects: Semiconductor doping