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

本实验的目的是利用一种新型的微波模式（2.45GHz）产生直径大于20 cm的高密度ECR等离子体，并利用等离子体CVD法制备大面积非晶硅薄膜。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作用，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：（i）当等离子体密度较低时，共振点前R波和L波都存在，共振点后只有L波存在;（ii）当等离子体密度较高时，只有R波存在。(2)在大多数实验中观察到的驻波图是由L波形成的。(3)我们测量径向传播的波和传播方向使用混频器和移相器。发现X波在磁场中传播。到目前为止，还没有在ECR等离子体中观察到X波。(4)我们用带有加热器的朗缪尔探针和微波干涉仪测量了稀释在He或H2中的硅烷等离子体的参数。发现有很多负离子。这将是必要的，以确定负离子物种。(5)我们在玻璃衬底上沉积了非晶硅薄膜，并估算了沉积速率和电导率。获得了沉积速率为15 /sec的高质量薄膜。(6)我们研究了等离子体参数对气体流速的依赖性。结果表明，在50 sccm以上，沉积速率较高。(7)这些结果对大面积薄膜的制备具有重要的参考价值，对大面积薄膜的制备研究具有一定的推动作用。

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.