等离子体增强化学气相沉积工艺制备SiON膜及对硅的钝化

Preparation of SiON film by plasma enhanced chemical vapor deposition and passivation on Si

研究了等离子体增强化学气相沉积工艺条件对氮氧化硅膜的生长厚度及折射率的影响以及氮氧化硅/氮化硅叠层膜对p型硅片的钝化效果.实验结果表明,NH3的流量和N2O/SiH4流量比对氮氧化硅膜的影响较大,薄膜折射率能从1.48变化到2.1,厚度从30—60 nm不等.腔内压力和射频功率主要影响膜厚,压力越大,功率越大,沉积速率加快,生成的膜越厚.温度对膜厚和折射率的影响可以忽略.钝化效果显示,在有无NH3下,N2O/SiH4流量比分别为20和30时,退火后氮氧化硅/氮化硅叠层膜对p型硅的钝化效果最好,其潜在电压和少子寿命分别为652 mV,56.7μs和649 mV,50.8μs,均优于参照组氮化硅膜样品的钝化效果.

The influences of technological condition on thickness and refractive index of the SiON films preprared by plasma enhanced chemical vapor deposition and the influence of SiON/SiNx stacked film on passivation performance on P-type silicon wafer are investigatied. The results show that the refractive index of SiON film varies from 1.48 to 2.1 and thickness varies from 30-60 nm by changing the gas flow of NH3 and the gas flow ratio of N2O/SiH4. The pressure and RF power mainly affect the thickness of the film. The greater the pressure, the higher the RF power, the faster the deposition rate is and the thicker the film is. The influences of temperature on the film thickness and refractive index can be ignored. The passivation shows that the passivation performance of P-type silicon film after annealing SiON/SiNx stacked films with a gas flow ratio of N2O/SiH4 20 and 30 in the absence and the presence of NH3, is best, which the implied voltages and the lifetimes of minority carriers are 652 mV, 56.7 μs and 649 mV, 50.8 μs, respectively. The passivation effect of SiON/SiNx stacked film is superior to that of the reference SiNx film.