Research on a functional inverter discharge plasma and a deposition of low frictional thin films for metal mechanical parts

将逆变器直接驱动技术应用于直流辉光放电系统中，该系统的背景压力为10^1 ~ 10^3 Pa。由于该系统产生的等离子体具有与直流等离子体基本相似的特性，因此我们可以使用简单的放电电极，如平行板，可以以低成本扩展到大面积处理。此外，由逆变电路的双极脉冲驱动的等离子体具有充电抵消功能，有利于隔离表面处理。从这项研究中，我们得到了以下结果。我们在一对平行板电极之间产生了压力为100pa的氩等离子体。峰值等离子体密度和温度分别为1 ~ 6×10^<10> cm^<-1>和2 ~ 6 eV，表明该放电可用于实际的表面处理和薄膜沉积。采用异步高压交变脉冲方式，提高了溅射薄膜在上述中压区下的粘附性能。接下来，进行了类金刚石（DLC）薄膜沉积实验。在100 ~ 600Pa（甲烷）压力下，以1.5μm/h的沉积速率在SUS304和Si（100）衬底上沉积了DLC薄膜。通过薄膜厚度测量、显微维氏硬度测试、原子力显微镜（AFM）、红外光谱（FTIR）和拉曼散射光谱（Raman Scattering Spectroscopy）对DLC薄膜的基本特性进行了估计。作为滑动试验的实际结果，我们还观察到涂有DLC薄膜的金属部件之间的动摩擦系数降低。

An inverter-direct-driving technique has been introduced to a dc glow discharge system in a middle background pressure resion (10^1〜10^3 Pa) obtained with rotary pumps. Because the plasma produced with the developed system has the similar properties as those of dc plasmas basically, we can utilize simple discharge electrodes such as parallel plates that would be extended for large area processing in a low cost. In addition, the plasma driven by the bipolar pulses from the inverter circuit has a charge-up cancellation function that is advantageous to isolated surface treatments.We have obtained the following results from this research.1.We produced an Ar plasma at a pressure of 100 Pa between a pair of parallel-plate electrodes. The peak plasma density and temperature were 1〜6×10^<10> cm^<-1> and 2〜6 eV, which indicates that this discharge can be applicable to practical surface treatment and film deposition.2.Using an asynchronous high-voltage alternating pulsing mode, we have improved the adhesion property of a sputtering thin film under the above middle pressure region.Next, a diamond-like carbon (DLC) film deposition experiment has been performed. The DLC films have deposited on SUS304 and Si (100) substrates under a pressure of 100〜600Pa (methane) at a deposition rate of 1.5μm/h. The basic characteristics of the DLC films have been estimated with film thickness measurement, micro Vickers hardness test, AFM, FTIR, and Raman Scattering Spectroscopy. As a practical result of a sliding test, we have also observed the decrease of the kinetic friction coefficient between metal parts coated with the DLC films.