Preparation of Ceramics Coating Films and Surface Modification by Controlled Plasmas

FCR等离子体沉积装置于1988年建成。该仪器配有光学发射光谱仪和静电探针，用于等离子体诊断。样品可以加热到800ºC，并偏向于所需的颗粒物质轰击在衬底上。通过改变放电压力、微波功率、衬底偏压和温度，对Zr、Ti和Ta进行了一系列的硝化实验。对氮等离子体法硝化后的样品与常规气体法硝化后的样品进行了比较。用俄歇电子能谱法测定了表面的氮含量。结果表明，等离子体硝化比气体硝化更有效。特别是在较低的温度（500-600℃）下，氮等离子体也能很好地硝化材料表面。随着放电压力的降低，离子相对于氮自由基占主导地位。在这种情况下，离子的硝化作用进行得很好。虽然认为氮自由基对硝化作用是有效的，但本实验表明，离子种类对硝化作用非常有效。然后我们尝试通过对衬底施加负电压来增强离子种类。随着离子通量（即负偏压电位）的增加，硝化过程也随之进行。实验表明，受控等离子体对表面改性有很大的调节作用。

FCR plasma Deposition Device had been constructed in 1988. Optical emission spectrometer and electro-static probe have been attached to this apparatus for plasma diagnostics. The sample can be heated up to 800ﾟC and be biased to for desirable particle species to bombard on the substrate. By changing discharge pressure, microwave power, substrate bias and temperature, we had a series of nitrization experiments for Zr, Ti and Ta. The nitrized sample due to nitrogen plasma was compared with that due to usual gas nitrization. The nitrogen content at the surface was determined by Auger Electron Spectroscopy.It was observed that the plasma nitrization was more effective than the gas nitrization. In particular, the material surface was well nitrized by nitrogen plasmas even at lower temperature (500-600ﾟC). As the discharge pressure was reduced, the ion species relatively became dominant than the nitrogen radical species. In this case, the nitrization very well progressed by the ion species. Although it was believed that the nitrogen radical was effective for nitrization, the present experiment showed that ion species was very effective for the nitrization. We then tried to enhance the ion species by applying negative voltage to the substrate. The nitrization progressed as the increase of ion flux, i.e. negative bias potential. This experiment showed that the surface modification could be considerably adjusted by the controlled plasma.