关键词: 超低阻值, 重掺磷, 硅单晶, 数值模拟, 界面形状, 组分过冷

Abstract: The production of heavily phosphorus-doped silicon single crystals with ultra-low resistivity is primarily constrained by constitutional supercooling induced by high-concentration doping and crystal-melt interface deformation during Czochralski growth. In this study, to investigate the persistent lattice mismatch observed at a crystal length of approximately 1 000 mm during production, simulations were performed using CGSIM finite element software. It was demonstrated that the lattice mismatch originated from the elevation of the crystal-melt interface and phosphorus impurity segregation. And an improvement was proposed. The results indicate that interface height can be reduced by lowering crystal rotation, growth rate, and melt gap, while increasing crucible rotation. Based on the constitutional supercooling criterion V/G (crystal growth rate V divided by melt temperature gradient G), crystal pulling is conducted with a reduced V value to mitigate supercooling effects. By applying optimized parameters, dislocation-free 8-inch (1-inch=2.54 cm) heavily phosphorus-doped silicon single crystals are successfully grown over 5 consecutive cycles. The measured resistivity ranges from 0.000 93 Ω·cm to 0.001 25 Ω·cm, further validating the simulation results.

Key words: ultra-low resistivity, heavily phosphorus doping, silicon single crystal, numerical simulation, interface shape, constitutional supercooling