冶金法n型多晶硅磷、硼吸杂实验的研究

Research on P/ B Gettering of Upgraded Metallurgical Grade n-type Multicrystalline Silicon Wafers

摘要:

研究了冶金法n型多晶硅片磷、硼吸杂效果及其机理。实验表明：经1000℃ 4h磷吸杂后,硅片平均少子寿命从1.21 μs 提高到11.98 μs；经950℃ 1h硼吸杂后，平均少子寿命从1.52μs提升到10.74 μs。两种吸杂处理后，硅片电阻率从0.2 Ω?cm提高到0.5 Ω?cm。结果表明，两种吸杂工艺使得硅片表面重磷、重硼扩散层对金属杂质有较好的吸杂作用，从而减少载流子的复合中心，改善多晶硅片的性能

Abstract:

The effect and mechanism of phosphorus / boron gettering of upgraded metallurgical grade (UMG) n-type mc-Si wafers were systematically investigated. The results show that the minority carrier lifetime and resistivity are improved greatly after getterring treatment. The lifetime is increased from 1.21 μs to 11.98 μs and 10.74 μs by phosphorus gettering and boron gettering at 1000℃ for 4 hours and 950℃ for 1 hour thermal treatment, respectively. It is concluded that the improvements are mainly due to the heavy phosphorous and boron diffusion layer formed on the surface, which can absorb the heavy metal impurities and decrease recombination centers.