Effect of PECVD SiN_x/SiO_yN_x–Si interface property on surface passivation of silicon wafer

• 作 者: 贾晓洁 周春兰 朱俊杰 周肃 王文静
• 机 构: The Key Laboratory of Solar Thermal Energy and Photovoltaic System,Institute of Electrical Engineeri
• 出 处: Chinese Physics B
• 发表日期: 2016年12期
• 关键词: wafer recombination saturation PECVD charges inserting annealing trapping anneal

It is studied in this paper that the electrical characteristics of the interface between Si O_y N_x/Si N_x stack and silicon wafer affect silicon surface passivation. The effects of precursor flow ratio and deposition temperature of the Si O_y N_x layer on interface parameters, such as interface state density Ditand fixed charge Qf, and the surface passivation quality of silicon are observed. Capacitance–voltage measurements reveal that inserting a thin Si O_y N_x layer between the Si N_x and the silicon wafer can suppress Qfin the film and Ditat the interface. The positive Qfand Ditand a high surface recombination velocity in stacks are observed to increase with the introduced oxygen and minimal hydrogen in the Si O_y N_x film increasing. Prepared by deposition at a low temperature and a low ratio of N_2O/Si H_4 flow rate, the Si O_y N_x/Si N_x stacks result in a low effective surface recombination velocity(Seff) of 6 cm/s on a p-type 1 ?·cm~(–5) ?·cm FZ silicon wafer.The positive relationship between Seffand Ditsuggests that the saturation of the interface defect is the main passivation mechanism although the field-effect passivation provided by the fixed charges also make a contribution to it.

It is studied in this paper that the electrical characteristics of the interface between Si O_y N_x / Si N_x stack and silicon wafer affect silicon surface passivation. The effects of precursor flow ratio and deposition temperature of the Si O_y N_x layer on interface parameters, such as interface state density Ditand fixed charge Qf, and the surface passivation quality of silicon are observed. Capacitance-voltage measurements that insert a thin Si O_y N_x layer between the Si N_x and the silicon wafer can suppress Qfin the film and Ditat the interface. positive Qfand Ditand a high surface recombination velocity in stacks are observed to increase with the introduced oxygen and minimal hydrogen in the Si O_y N_x film increasing. Prepared by deposition at a low temperature and a low ratio of N 2 O / Si H 4 flow rate, the Si O_y N_x / Si N_x stacks result in a low effective surface recombination velocity (Seff) of 6 cm / s on a p-type 1 · · cm ~ (-5) · · cm FZ silicon wafer.The positi ve relationship between Seffand Ditsuggests that the saturation of the interface defect is the main passivation mechanism although the field-effect passivation provided by the fixed charges also make a contribution to it.