腔室长时间使用造成的工艺漂移对微晶硅薄膜性质的影响  

Effects of Drift Due to Chamber's Long-time Usage on Microcrystalline Silicon Properties

作　　者：张鹤[1] 戴志华[1] 张晓丹[1] 魏长春[1] 孙建[1] 耿新华[1] 赵颖[1] 

机构地区：[1]南开大学光电子薄膜器件与技术研究所,天津300071

出　　处：《科技导报》2009年第20期19-21,共3页Science & Technology Review

基　　金：国家重点基础研究发展计划(973计划)项目(2006CB202602;2006CB202603);国家自然科学基金项目(60506003);国家科技计划配套项目(07QTPTJC29500)

摘　　要：考查了等离子体增强化学气相沉积(PECVD)高压制备微晶硅(μc-Si:H)薄膜过程中,系统长时间使用造成的微晶硅薄膜特性的漂移情况。实验中,控制沉积条件,使薄膜的沉积速率达到约0.5nm/s;保证硅薄膜具有一定的晶化程度(40%～80%),由不同探测波长的Raman散射谱估算纵向结构变化。以腔室使用时间作为基准,考查不同硅烷浓度下制备的样品,发现在相同沉积条件下,材料的晶化率和光暗电导随腔室使用时间的增加而不断增大,沉积速率随之大幅提高。观察发现,在电极板和腔室壁上积累了大量硅反应残留物(硅粉末和硅薄膜),分析认为,薄膜特性漂移是这些硅残留物不断参与等离子体及成膜反应的结果。研究表明,提高硅烷浓度可有效校正微晶硅薄膜电学及结构特性的漂移,同时保持高速沉积。This paper investigates the drift of microcrystalline silicon （μc-Si：H） thin film properties due to the chamber＇s long-time usage in plasma enhanced chemical vapor deposition （PECVD）. The condition parameters were controlled to reach about 0.5 nm/s deposition rate for the samples to have a certain crystalline degree, 40%-80%, as detected and estimated by two different wavelength lasers in Raman scattering measurement. The samples under different silane concentrations （i.e. the flow rate ratio, [SiH4]/（[SiH4]＋ [H2]）） were compared carefully, and it is found that both their deposition rate and crystalline degree increase with the chamber usage time, which was used as an independent variable in this experiment. This phenomenon may be explained by the accumulated silicon remains such as powders and films, observed on the electrode plate and/or on the chamber wall in this experiment. These silicon remains probably take part in the reactions related to the film formation in plasma. It is found that this drift of μc-Si：H structural and electronic properties can be adjusted by increasing the silane concentration, and with the deposition rate being kept at a high level.

关 键 词：微晶硅薄膜 等离子体增强化学气相沉积 工艺漂移 硅粉末 

分 类 号：O484.1[理学—固体物理]