| The technology of plasma has been applied in the preparation of semiconductor film materials and microelectronic industry. Plasma Chemical Vapor Deposition is the most effective way in the deposition of high quality films for the mass-production because its mature technology. It has been increasingly attached importance to directly deposit the poly-silicon films, using SiCl4/H2, in conventional radio frequency glow discharge PCVD system. It is necessary to know the discharge mechanism in various conditions, diagnose and control the discharge process for searching for the optimum technology parameters of the deposition of films with high efficiency and high quality . Langmuir single probe is an important method for diagnosing the charged particle parameters of the plasma.However, it is not known whether the probe can be applied to measurement in SiCl4/H2 radio frequency glow discharge. This paper first study the possible erodent effect and contamination effect during probe works in rf glow discharge SiCl4/H2 plasma. There is a large amount of HC1 in the SiCl4/H2 plasma space, which makes the acidity condition. In the experiment, tungsten filament was used as probe for its high melting point and bombardment-resistant. At the same time, as a kind of heavy metal, tungsten has less chemical activity and difficultly react with strong hydrochloric acid. The result of the experiment show that probe can work without erosion.In SiH4 radio frequency discharges plasma, the a-Si:H thin films deposited on the probe surface with high resistance seriously influence the collection of the electron at below 200℃, which makes â… -â…¤ curves deform, known as "contamination effect". While in SiCl4/H2 plasma, The effect of varies temperatures on the current collected by probe was studied. It was found that good â… -â…¤ characteristic curves can be measured at 100℃, which is because that crystal silicon grains with high conductivity exist in the plasma space during the deposition of poly-silicon thin films from SiCl4/H2 mixture gases.In this paper, the electron energy distribution function, the mean electron energy and the electron concentration in SiCl4/H2 radio frequency glow discharge plasma space were systemically measured using a tuned probe. The dependence of electron characters on PCVDtechnology parameters and on the photoelectric characters of films were analyzed. The results of experiment provide a credible experiment basis for the growth mechanism of poly-silicon films deposited at low temperature-high rate in conventional radio frequency glow discharge PCVD system using SiCU/H?.
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