Deposition Process Study Of Device Quality A-Si:H Film By Method Of MWECR CVD With High Deposition Rate

Hydrogenated amorphous silicon (a-Si:H) has been widely used in thehigh-technology field, such as film solar cells, film transistor and flatdisplay, etc . But the deposition rate and quality of a-Si:H thin filmwere primarily determined by it's deposition method. In order to obtaindevice quality a-Si:H with high deposition rate for furtherindustrializations, the microwave electron cyclotron resonance (MWECR)CVD technology was developed with the virtue of high degree electronand ion generation capability and has attracted great attention. However,Because of its complex deposition mechanism ,the characters of plasmawere affected by various process parameters, through which the qualityof a-Si:H thin film were determined. The deposition mechanism is so complex that no complete theory aboutit has been built up to now. By means of infrared (IR) spectrum andconductivity measurement ,etc ,we analysis film's qulity while focusedon the effects of various process parameters on plasma. Some parametershave been optimized, Such as the dilution ratio of H2/SiH4 ,the depositionpressure, the substrate temprature, and configuration of magnetic field. For the repetition of device quality a-Si:H deposition as well asdecreasing its unstability under photo illumination, we integrated a hotwire unit into our MWECR CVD system ,which was a new idea used for thefirst time. As indicated by experiment, hot wire has the capability ofstimulate the decomposition of H2 and SiH4.Consequently, active particlein plasma increased and the quality of a-Si:H was improved apparently.The experimentally optimized hot wire temperature was 1400ｏC ,in whichcondition photo sensitivity of 3x105 and deposition rate above 20?/s wereobtained. Meanwhile , unstability under photo illumination was decreased.At the same time, we also investigated the a-Si:H film's evenness -II-摘 要deposited by HW MW ECRCVD system.It seemed that MW ECRCVD assisted byHW unit can improve the evenness value from about 19% to 10.9%.