Development of the Device for Producing a Large Area Thin Film by a New Maicrowave Mode

目的是用一种新型的微波模式(2.45 GHz)产生直径大于20 cm的高密度ECR等离子体，并用等离子体CVD制备大面积非晶硅薄膜。我们用九州大学研制的多槽天线进行了实验。获得的主要结果如下：(1)为了研究微波传播对等离子体均匀性的影响，我们利用混频器测量了微波在ECR等离子体中的轴向传播。结果表明：(1)当等离子体密度较低时，R波和L波都存在于谐振点之前，只有L波存在于谐振点之后；(Ii)当等离子体密度较高时，只有R波存在.(2)大多数实验中观察到的驻波都是由L波形成的.(3)我们用混频器和移相器测量了径向传播波和传播方向.发现有X波在磁场中传播。目前还没有在ECR等离子体中观察到x波。(4)我们用加热器和微波干涉仪的朗缪尔探头测量了在氦或氢中稀释的硅烷等离子体的参数。发现存在大量的负离子。我们在玻璃衬底上沉积了非晶硅薄膜，并估算了薄膜的沉积速率和电导率。获得了沉积速率为15次/秒的高质量薄膜。(6)考察了气体流量对等离子体参数的影响。以上结果对于大面积薄膜的制备是非常重要的数据，本实验将对大面积薄膜制备的研究起到推动作用。

The objective is to produce a high density ECR plasma with the diameter larger than 20 cm using a new type of microwave mode (2.45GHz) and to prepare a large area amorphous silicon film by plasma CVD.We have performed the experiments using a multi-slot antenna develomed at Kyushu University. Obtained main results are as follows :(1) In order to study the role of microwave propagation in plasma uniformity, we measured the axial propagation of the microwave in ECR plasma using a mixer. It was found that (i) when the plasma density is low, both the R-wave and L-wave exist before the resonant point and onlythe L-wave does after the resonant point, and (ii) when the plasma density is high, only the R-wave exists.(2) The standing patterns which have been observed in the most of the experiments were formed by the L-wave.(3) We measured radially propagating waves and the propagation direction using a mixer and a phase shifter. It was found that there is the X-wave propagating across the magnetic field. The x-wave has not been observed in ECR plasma, so far.(4) We measured the parameters of the silane plasmas diluted in He or H2 with the Langmuir probe with a heater and a microwave interferometer. It was found that there are a lot of negative ions. It will be neccesary to identify negative ion species.(5) We deposited amorphous silicon films on the glass substrates and estimated the deposition rate and the conductivity. The high quality films with the deposition rate of 15 /sec were obtained.(6) We examined the dependence of the plasma parameters on the gas flow rate. It was found that higher deposition rate would be achieved above 50sccm.(7) Above results are very important data for depositing a large area thin film and the present experiments will make the advancement the study on the preparation of a large area thin film.