链式氧化制备SiO2膜的研究

研究了应用链式扩散设备对经过制绒、清洗、扩散和刻蚀处理后的单晶P型硅片进行热氧化SiO2膜的生长。采用准稳态光电导衰减法(QSSPC)在室温条件下对氧化前后硅片的少子寿命进行测试,探讨了氧化工艺条件对少子寿命、SiO2薄膜质量的影响机理,并对氧化工艺进行了优化。实验结果表明:在氧气流量为20L/min,带速为13i/m,氧化工艺区阶梯式温度设置为600、800、800、800、800、800、850和900℃时,链式氧化后硅片少子寿命达到42.5μs,SiO2膜的厚度适合,结构致密;在不影响减反效果的情况下,获得了良好的钝化效果。

Investigation on SiO2 Film Produced by Inline Oxidation

The thermal growth of SiO2 film on p-type monocrystal silicon wafers by in-line diffusion equipment was investigated after the wafers were processed with texturing,rinse,diffusion and etching.The minority carrier lifetime of silicon wafers before and after oxidation were measured by a Quasi-Steady-State Photoconductance(QSSPC) decay technique under an ambient condition.The oxidation processes were optimized,and also,its influence on the lifetime of minority carriers and SiO2 film quality was analyzed.The results show that under the conditions of oxygen flux 20 L/min,belt velocity 13 ipm(inches per minute),and the oxidation zones’ staircase temperatures 600 ℃,800 ℃,800 ℃,800 ℃,800 ℃,800 ℃,850 ℃,900 ℃ respectively,the minority carriers lifetime reaches 42.5 μs,and the SiO2 film gets appropriate thickness and performs good compact structure.In addition,the SiO2 film has better passivation performance under the condition of no harm to reflectivity gains.