Comparative studies of As and B diffusion as well as segregation in polysilicon on single-crystal Si systems were performed by secondary ion mass spectroscopy. Arsenic (1016/cm2; 100keV) or B (2 x 1015/cm2; 30keV), (and both of them with As and followed by B), were implanted in 380nm polysilicon laid by low-pressure chemical vapor deposition were diffused into the underlying Si substrate in effect of rapid thermal annealing (1000 to 1150C, 20s). Before the deposition of polysilicon, the oxide film was removed. Up to about 11 and 10% of implanted As atoms were 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 B atoms were segregated at the interface. The As and B doses distributed in the substrate were smaller than the doses segregated at the interface. The continuity of As and B profiles extrapolated to the interface, showed an absence of the diffusion barrier. Diffused As dose to the single crystalline Si showed a reduction of about 50% in the case of co-diffusion if compared to diffusion. As far as B was concerned, the difference was even higher which confirmed the stopping of the diffusion of the B in the presence of the As.

Diffusion and Segregation of Arsenic and Boron in Polysilicon/Silicon Systems during Rapid Thermal Annealing. A.Merabet: Journal of Alloys and Compounds, 2004, 382[1-2], 300-4