Transient Enhanced Diffusion of Phosphorus and Defect Evolution in P+ Implanted Si

Abstract

ABSTRACTContinuous scaling of device dimensions requires better understanding of non-equilibrium diffusion phenomena such as transient enhanced diffusion (TED). To this end, it is important to understand the relationship of the defect evolution with TED. Defect evolution in P+ implanted Si has been investigated by transmission electron microscopy (TEM). Secondary ion mass spectroscopy (SIMS) has been used to study phosphorus TED. These studies show that another type of defect, i.e. dot defects are present in P+implanted Si (100 keV, 1.OX104/cm2). The evolution of defects in P+ implants is compared with that in Si+ implants. P+ implants give rise to small dot defects mixed with {311} defects while Si+ implants give rise to only {311} defects. The dot defects and {311} defects in P+ implants dissolve faster than the {311} defects from Si+ implants. The interstitial concentration trapped in the dot defects and the {311} defects from P+ implants is slight lower than that from Si+ implants. Dot defects seem to have only a small role in phosphorus TED. Interaction of silicon interstitials emitted from the dissolution of {311} defects with phosphorus dopant atoms is believed to be the dominant driving force for the TED. There may also be a contribution from dissolution of non-visible phosphorus interstitial clusters (PIC's). Correlation of defect evolution and TED has been addressed.