退火温度对富硅氮化硅薄膜发光特性和结构的影响

采用直流等离子体增强化学气相沉积(PECVD)法在(100)单晶硅片表面生长富硅氮化硅薄膜,研究了不同的退火温度对氮化硅薄膜发光性质和结构的影响。研究发现,随着退火温度的升高,氮化硅薄膜的发光强度逐渐减弱,发光是由缺陷能级引起的,在900 ℃时荧光基本消失。XPS测试表明,在N₂氛围900 ℃下退火,氮化硅薄膜中未有硅相析出,故未表现出硅量子点的发光。FTIR测试也为PL结论提供了一定的证据。

Effect of Annealing Temperature on Photoluminescence Performance and Structure of Si-rich Silicon Nitride

Silicon-rich silicon nitride film was deposited by plasma enhanced chemical vapor deposition(PECVD) on(100)-oriented monocrystalline silicon,according to silicon solar cell process.Photoluminescence(PL) performance of the films at annealing temperatures in N2 ambient was studied,showing that temperatures had great effect on the characteristics.Excited by 325 nm line,PL from defect-related states was only observed in the film and Si clusters has not been formed at annealing temperature 900 ℃.After annealed at different temperature,PL intensity decreased with increasing temperature.PL peak originated from defect energy Si dangling bond(K center).In this work,At 900 ℃,disappearance of PL peak was attributed to increasing non-radiation recombination and silicon clusters has not been formed.Structure of silicon nitride has been measured by X-ray photo-electron spectroscopy(XPS) showing binding energy at 101.8 eV and indicated that silicon phase has not been separated from silicon nitride.Infrared(FTIR) measurement provided a good confirm to PL analysis.