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 

机构地区：[1]The Key Laboratory of Solar Thermal Energy and Photovoltaic System,Institute of Electrical Engineering,Chinese Academy of Sciences,University of Chinese Academy of Sciences [2]Solar Energy Department,Institute for Energy Technology

出　　处：《Chinese Physics B》2016年第12期403-407,共5页中国物理B（英文版）

基　　金：Project supported by the National High Technology Research and Development Program of China(Grant No.2015AA050302);the National Natural Science Foundation of China(Grant No.61306076)

摘　　要：It is studied in this paper that the electrical characteristics of the interface between SiOyNx/SiNx stack and silicon wafer affect silicon surface passivation. The effects of precursor flow ratio and deposition temperature of the SiOyNx layer on interface parameters, such as interface state density Dit and fixed charge Qf, and the surface passivation quality of silicon are observed. Capacitance-voltage measurements reveal that inserting a thin SiOyNx layer between the SiNx and the silicon wafer can suppress Qf in the film and Dit at the interface. The positive Qf and Dit and a high surface recombination velocity in stacks are observed to increase with the introduced oxygen and minimal hydrogen in the SiOyNx film increasing. Prepared by deposition at a low temperature and a low ratio of N2O/SiH4 flow rate, the SiOyNx/SiNx stacks result in a low effective surface recombination velocity （Self） of 6 cm/s on a p-type 1 Ω.cm-5 Ω.cm FZ silicon wafer. The positive relationship between Serf and Dit suggests 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 SiOyNx/SiNx stack and silicon wafer affect silicon surface passivation. The effects of precursor flow ratio and deposition temperature of the SiOyNx layer on interface parameters, such as interface state density Dit and fixed charge Qf, and the surface passivation quality of silicon are observed. Capacitance-voltage measurements reveal that inserting a thin SiOyNx layer between the SiNx and the silicon wafer can suppress Qf in the film and Dit at the interface. The positive Qf and Dit and a high surface recombination velocity in stacks are observed to increase with the introduced oxygen and minimal hydrogen in the SiOyNx film increasing. Prepared by deposition at a low temperature and a low ratio of N2O/SiH4 flow rate, the SiOyNx/SiNx stacks result in a low effective surface recombination velocity （Self） of 6 cm/s on a p-type 1 Ω.cm-5 Ω.cm FZ silicon wafer. The positive relationship between Serf and Dit suggests 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.

关 键 词：solar cell INTERFACE PASSIVATION 

分 类 号：TN304.055[电子电信—物理电子学]