ملخص: Comparative studies of arsenic and boron diffusion as well as segregation in polysilicon on single-crystal silicon systems have been performed by secondary ion mass spectroscopy. Arsenic (1016 atoms/cm2; 100 keV) or boron (2 x 1015 atoms/cm2; 30 keV), (and both of them with As and followed by B), have been implanted in 380 nm polysilicon laid by low-pressure chemical vapor deposition have been diffused into the underlying silicon substrate in effect of rapid thermal annealing for 20 s at temperatures ranging from 1000 to 1150 [deg]C. Before the deposition of polysilicon, the oxide film has been removed. Up to about 11 and 10% of implanted arsenic atoms are segregated at the interface in the case of diffusion and co-diffusion, respectively, while up to 2.6% (diffusion) and 4.45% (co-diffusion) of the implanted boron atoms are segregated at the interface. The As and B doses distributed in the substrate are smaller than the doses segregated at the interface. The continuity of arsenic and boron profiles extrapolated at the interface, shows on absence of the diffusion barrier. Diffused arsenic dose to the single crystalline Si shows a reduction of about 50% in the case of co-diffusion if compared to diffusion. As boron is concerned, the difference is even higher which confirms the stopping of the diffusion of the boron in the presence of the arsenic.

لغة: إنجليزية