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。该装置附有光发射光谱仪和静电探针，用于等离子体诊断。样品可以被加热到800摄氏度，并被偏置，以使所需的粒子种类轰击在衬底上。通过改变放电气压、微波功率、衬底偏压和温度，对Zr、Ti和Ta进行了一系列氮化实验。对氮气等离子体渗氮试样与普通气体渗氮试样进行了比较。用俄歇电子能谱仪测定了表面氮含量，发现等离子体渗氮比气体渗氮更有效。特别是，即使在较低的温度（500-600 ℃）下，材料表面也被氮等离子体很好地氮化。随着放电压力降低，离子物种相对于氮自由基物种变得占优势。在这种情况下，通过离子种类，氮化非常好地进行。虽然人们认为氮自由基对硝化是有效的，但本实验表明离子种类对硝化是非常有效的。然后，我们试图通过向衬底施加负电压来增强离子种类。随着离子流的增加，即负偏压的增加，氮化反应进行。该实验表明，通过受控等离子体可以显著地调节表面改性。

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.