Abstract :
In this experiment, nitrogen ions were implanted into CZ-silicon wafer at 100 keV at room temperature with the fluence of 5 1015 N2
+/cm2,
followed by rapid thermal processing (RTP) at different temperatures. The single detector Doppler broadening and coincidence Doppler
broadening measurements on slow positron beam were carried out to characterize the defects in the as-implanted silicon and RTP-treated samples.
It is found that both nitrogen-vacancy complexes (N-Vsi) and oxygen-vacancy complexes (O-Vsi) produced by nitrogen implantation diffuse back
to the sample surface upon annealing. But the N-Vsi and the O-Vsi complete with each other and give a summed effect on positron annihilation
characteristics. It is shown that the N-Vsi win out the O-Vsi in as-implanted sample and by RTP at 650 8C, 750 8C, which make the S-parameter
increase; O-Vsi plays a dominant role after annealing above 850 8C, which makes the S parameter decrease
