硅片不同表面钝化工艺的稳定性研究

Study on the Stability of the Silicon Wafers Passivated by Different Surface Passivation Processes

研究分析了热氧化钝化,用PECVD双面沉积SiNx:H膜钝化以及碘酒钝化三种表面钝化工艺的稳定性,通过WT-2000少子寿命测试仪对采用这三种钝化工艺的单晶硅片,多晶硅片以及物理提纯硅片在暗条件不同储存时间的少子寿命进行测量,分析得到三种表面钝化工艺的效果以及稳定性。研究结果表明:碘酒钝化效果好,用PECVD双面沉积SiNx:H膜钝化和热氧化钝化稳定性好。

The relationship of minority carrier lifetime of various silicon wafers with the time stored in dark condition was investigated by using WT-2000 tester. The silicon wafers include the primary wafer, the chemical thinned wafer, the wafer passivated by thermal oxidation, the wafer passivated by SiNx ： H film deposited by plasma enhanced chemical vapor deposition （PECVD） and the wafer passivated by io- dine solution. Three types of silicon wafers are B-doped CZ-silicon, B-doped Multicrystalline （MC） sili- con, B-doped upgraded-metallurgical-grade （UMG） silicon. As the results from fifteen types of silicon wafer specimens in total were used. Then the stability of the different surface passivation processes was studied. Finally, it was found that the passivation effect of iodine passivation is better, while the passiva- tion stability of SiNx ： H and thermal oxidation passivation is better.