偏压调控笼形空心阴极放电特性及Si-DLC厚膜结构与性能研究
发布时间：2018-11-21 10:35
【摘要】：类金刚石(DLC)膜具有低摩擦系数、高耐磨性以及优异耐腐蚀性能而得到广泛应用。随着现代工业的进步,业界对厚的DLC膜层越来越关注,因为需要更高的耐磨性和耐蚀性。在众多的DLC膜层制备方法中,笼形空心阴极放电具有等离子体密度高、膜层沉积快的优势,是制备DLC厚膜的一种有效方法。但由于工件与笼形阴极内等离子体电位差只有几个e V,限制了离子对DLC膜性能的调控和基体的清洗。针对这个问题,本文提出一种新型偏压调控笼形空心阴极放电沉积DLC膜技术。对其放电特性和偏压调控Si-DLC膜结构和性能进行了研究,并成功制备了具有高沉积速率和高结合力的Si-DLC多层厚膜(30μm)。偏压调控笼形空心阴极沉积系统,可通过施加在笼网上的激励电压来调整笼内等离子体密度,通过改变工件附加偏压值调控到达工件表面离子能量,从而实现等离子体密度与离子能量的独立控制。氩气和乙炔气体笼形空心阴极放电特性测试表明,随工作气压的升高,频率或脉宽的增大,击穿电压值降低。乙炔分子具有强电负性,容易与电子复合形成负离子,导致相同气压下乙炔放电击穿电压高于氩气放电。笼形空心阴极系统放电包括预放电和空心阴极放电两个阶段。氩气放电初始阶段存在电流下降现象,主要是Ar~+离子刻蚀减少笼网表面污染物及凸起结构平滑化,笼网表面电子发射数量减少的原因。氩气放电过程随气压升高,离化增强,笼网电流增大。乙炔放电过程,强电负性乙炔气体分子与电子复合形成负离子,降低电子数量,导致放电减弱。氩气放电过程,偏压幅值对笼形空心阴极氩气放电特性的影响存在阈值,偏压高于阈值时自辉光放电增强,有利于提高等离子体密度,低于阈值时偏压电场消弱空心阴极效应,辉光放电弱化。混合气体放电过程,氩气促进乙炔气体分解和离化。等离子体光谱测试表明,氩气放电空间粒子主要为Ar~+离子和激活态Ar*原子,乙炔放电空间粒子主要检测到原子态H和少量的CH、C2和C~+离子。建立Ar~+离子运动模型,从微观角度解释了电流波形变化机制。Ar~+和H~+离子偏压刻蚀减少316不锈钢基体表面碳污染物,并形成尺寸在20nm-50nm的纳米凸起结构,增强“锁扣”效应,提高膜基结合强度。Ar~+和H~+离子偏压刻蚀有效去除不锈钢氮化层表面疏松氮化物颗粒,减少氧元素含量,进一步提高膜基结合强度。偏压调控笼形空心阴极系统沉积Si-DLC膜,附加偏压降低Si-DLC膜层的表面粗糙度,提高膜层致密性。随偏压增大,Si-DLC膜沉积速率呈现先降低后增加的变化规律,先降低是由于原子氢化学刻蚀和Ar~+离子溅射占主导因素,后增加是由于工件自辉光放电增强乙炔的分解。膜层结构的致密化和H含量的降低是提高Si-DLC膜力学性能的主要因素。Si-DLC膜纳米硬度由8GPa升高到14GPa,-300V附加偏压制备的Si-DLC膜具有较好的耐钢球摩擦磨损性能。与常规笼形空心阴极沉积的Si-DLC单层膜相比,偏压调控软硬交替SiDLC多层膜结构,提高了膜层的整体韧性和膜基结合强度。316不锈钢/SiDLC膜基体系划痕结合力L_(C2)值由17 N升高到30N。同时,采用偏压调控笼形空心阴极系统,实现316不锈钢氮化和偏压调控多层Si-DLC膜连续制备,L_(C2)值提高到46N。随多层膜厚度增大,高速钢基体Si-DLC多层膜划痕韧性值逐渐升高,厚度为35μm时达到2695,L_(C2)值达到112N。Si-DLC多层膜具有较低的摩擦系数和优异的耐GCr15和Si C对磨球摩擦磨损性能。多层SiDLC膜热稳定性优于常规笼形空心阴极技术制备的Si-DLC单层膜。偏压调控和多层结构设计增大了Si-DLC膜致密度,减少了膜层内针孔缺陷,表现出优异的耐15%HCl侵蚀能力。采用偏压调控笼形空心阴极技术,在硅片上成功制备厚度为152μm的Si-DLC膜。
[Abstract]:Diamond-like (DLC) films have a low coefficient of friction, high wear resistance, and excellent corrosion resistance. With the advancement of modern industry, the industry has become more and more concerned with thick DLC film layers, as higher wear resistance and corrosion resistance are required. in the preparation method of a plurality of DLC film layers, the cage-shaped hollow cathode discharge has the advantages of high plasma density and fast film deposition, and is an effective method for preparing the DLC film. but due to the fact that the plasma potential difference of the workpiece and the cage-shaped cathode is only a few e v, the regulation of the performance of the DLC film and the cleaning of the substrate are limited. In this paper, a new type of bias control cage-shaped hollow cathode discharge deposited DLC film technology is proposed in this paper. The structure and properties of Si-DLC films with high deposition rate and high bonding force were studied and the Si-DLC multilayer thick films (30. mu.m) with high deposition rate and high bonding force were successfully prepared. the bias control cage-shaped hollow cathode deposition system can adjust the plasma density in the cage by applying the excitation voltage on the cage network, and regulate the ion energy reaching the surface of the workpiece by changing the additional bias value of the workpiece so as to realize the independent control of the plasma density and the ion energy. The discharge characteristics of the gas-cage-shaped hollow cathode of argon and acetylene show that the breakdown voltage is decreased with the increase of working air pressure, the increase of frequency or pulse width and the decrease of the breakdown voltage. the acetylene molecules have strong electronegativity, and are easy to form negative ions with the electron, so that the discharge breakdown voltage of the acetylene under the same air pressure is higher than that of the argon. The cage-shaped hollow cathode system discharge includes two stages of pre-discharge and hollow cathode discharge. There is a phenomenon of current drop in the initial stage of the argon discharge, mainly the reason that Ar ~ + ion etching reduces the surface pollutant and the convex structure of the cage net, and the number of electron emission on the surface of the cage net is reduced. The process of argon discharge increases with the air pressure, and the current of the cage net is increased. the process of acetylene discharge, strong electronegativity negative acetylene gas molecules and the electron recombination form negative ions, the electronic quantity is reduced, and the discharge is reduced. In the process of argon discharge, the influence of the bias amplitude on the discharge characteristics of the cage-shaped hollow cathode is a threshold value, the self-glow discharge is enhanced when the bias voltage is higher than the threshold value, the plasma density is improved, the bias electric field is biased to eliminate the weak hollow cathode effect when the bias voltage is lower than the threshold value, and the glow discharge is weakened. In the process of mixed gas discharge, argon is used to promote the decomposition and ionization of acetylene gas. The plasma spectrum test shows that the Ar + ions and the activated Ar * atoms in the argon discharge space mainly detect the atomic state H and the small amount of CH, C2 and C ~ + ions. The model of Ar ~ + ion motion is set up, and the change mechanism of the current waveform is explained from the micro-angle. Ar ~ + and H ~ + ion bias etching can reduce the carbon contamination on the surface of 316 stainless steel matrix, and form the nano-convex structure with the size of 20nm-50nm, enhance the 鈥渓ock catch鈥，
本文编号：2346726
[Abstract]:Diamond-like (DLC) films have a low coefficient of friction, high wear resistance, and excellent corrosion resistance. With the advancement of modern industry, the industry has become more and more concerned with thick DLC film layers, as higher wear resistance and corrosion resistance are required. in the preparation method of a plurality of DLC film layers, the cage-shaped hollow cathode discharge has the advantages of high plasma density and fast film deposition, and is an effective method for preparing the DLC film. but due to the fact that the plasma potential difference of the workpiece and the cage-shaped cathode is only a few e v, the regulation of the performance of the DLC film and the cleaning of the substrate are limited. In this paper, a new type of bias control cage-shaped hollow cathode discharge deposited DLC film technology is proposed in this paper. The structure and properties of Si-DLC films with high deposition rate and high bonding force were studied and the Si-DLC multilayer thick films (30. mu.m) with high deposition rate and high bonding force were successfully prepared. the bias control cage-shaped hollow cathode deposition system can adjust the plasma density in the cage by applying the excitation voltage on the cage network, and regulate the ion energy reaching the surface of the workpiece by changing the additional bias value of the workpiece so as to realize the independent control of the plasma density and the ion energy. The discharge characteristics of the gas-cage-shaped hollow cathode of argon and acetylene show that the breakdown voltage is decreased with the increase of working air pressure, the increase of frequency or pulse width and the decrease of the breakdown voltage. the acetylene molecules have strong electronegativity, and are easy to form negative ions with the electron, so that the discharge breakdown voltage of the acetylene under the same air pressure is higher than that of the argon. The cage-shaped hollow cathode system discharge includes two stages of pre-discharge and hollow cathode discharge. There is a phenomenon of current drop in the initial stage of the argon discharge, mainly the reason that Ar ~ + ion etching reduces the surface pollutant and the convex structure of the cage net, and the number of electron emission on the surface of the cage net is reduced. The process of argon discharge increases with the air pressure, and the current of the cage net is increased. the process of acetylene discharge, strong electronegativity negative acetylene gas molecules and the electron recombination form negative ions, the electronic quantity is reduced, and the discharge is reduced. In the process of argon discharge, the influence of the bias amplitude on the discharge characteristics of the cage-shaped hollow cathode is a threshold value, the self-glow discharge is enhanced when the bias voltage is higher than the threshold value, the plasma density is improved, the bias electric field is biased to eliminate the weak hollow cathode effect when the bias voltage is lower than the threshold value, and the glow discharge is weakened. In the process of mixed gas discharge, argon is used to promote the decomposition and ionization of acetylene gas. The plasma spectrum test shows that the Ar + ions and the activated Ar * atoms in the argon discharge space mainly detect the atomic state H and the small amount of CH, C2 and C ~ + ions. The model of Ar ~ + ion motion is set up, and the change mechanism of the current waveform is explained from the micro-angle. Ar ~ + and H ~ + ion bias etching can reduce the carbon contamination on the surface of 316 stainless steel matrix, and form the nano-convex structure with the size of 20nm-50nm, enhance the 鈥渓ock catch鈥，
本文编号：2346726
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