【摘要】：類金剛石(DLC)膜具有低摩擦系數(shù)、高耐磨性以及優(yōu)異耐腐蝕性能而得到廣泛應(yīng)用。隨著現(xiàn)代工業(yè)的進(jìn)步,業(yè)界對厚的DLC膜層越來越關(guān)注,因?yàn)樾枰叩哪湍バ院湍臀g性。在眾多的DLC膜層制備方法中,籠形空心陰極放電具有等離子體密度高、膜層沉積快的優(yōu)勢,是制備DLC厚膜的一種有效方法。但由于工件與籠形陰極內(nèi)等離子體電位差只有幾個e V,限制了離子對DLC膜性能的調(diào)控和基體的清洗。針對這個問題,本文提出一種新型偏壓調(diào)控籠形空心陰極放電沉積DLC膜技術(shù)。對其放電特性和偏壓調(diào)控Si-DLC膜結(jié)構(gòu)和性能進(jìn)行了研究,并成功制備了具有高沉積速率和高結(jié)合力的Si-DLC多層厚膜(30μm)。偏壓調(diào)控籠形空心陰極沉積系統(tǒng),可通過施加在籠網(wǎng)上的激勵電壓來調(diào)整籠內(nèi)等離子體密度,通過改變工件附加偏壓值調(diào)控到達(dá)工件表面離子能量,從而實(shí)現(xiàn)等離子體密度與離子能量的獨(dú)立控制。氬氣和乙炔氣體籠形空心陰極放電特性測試表明,隨工作氣壓的升高,頻率或脈寬的增大,擊穿電壓值降低。乙炔分子具有強(qiáng)電負(fù)性,容易與電子復(fù)合形成負(fù)離子,導(dǎo)致相同氣壓下乙炔放電擊穿電壓高于氬氣放電。籠形空心陰極系統(tǒng)放電包括預(yù)放電和空心陰極放電兩個階段。氬氣放電初始階段存在電流下降現(xiàn)象,主要是Ar~+離子刻蝕減少籠網(wǎng)表面污染物及凸起結(jié)構(gòu)平滑化,籠網(wǎng)表面電子發(fā)射數(shù)量減少的原因。氬氣放電過程隨氣壓升高,離化增強(qiáng),籠網(wǎng)電流增大。乙炔放電過程,強(qiáng)電負(fù)性乙炔氣體分子與電子復(fù)合形成負(fù)離子,降低電子數(shù)量,導(dǎo)致放電減弱。氬氣放電過程,偏壓幅值對籠形空心陰極氬氣放電特性的影響存在閾值,偏壓高于閾值時自輝光放電增強(qiáng),有利于提高等離子體密度,低于閾值時偏壓電場消弱空心陰極效應(yīng),輝光放電弱化�；旌蠚怏w放電過程,氬氣促進(jìn)乙炔氣體分解和離化。等離子體光譜測試表明,氬氣放電空間粒子主要為Ar~+離子和激活態(tài)Ar*原子,乙炔放電空間粒子主要檢測到原子態(tài)H和少量的CH、C2和C~+離子。建立Ar~+離子運(yùn)動模型,從微觀角度解釋了電流波形變化機(jī)制。Ar~+和H~+離子偏壓刻蝕減少316不銹鋼基體表面碳污染物,并形成尺寸在20nm-50nm的納米凸起結(jié)構(gòu),增強(qiáng)“鎖扣”效應(yīng),提高膜基結(jié)合強(qiáng)度。Ar~+和H~+離子偏壓刻蝕有效去除不銹鋼氮化層表面疏松氮化物顆粒,減少氧元素含量,進(jìn)一步提高膜基結(jié)合強(qiáng)度。偏壓調(diào)控籠形空心陰極系統(tǒng)沉積Si-DLC膜,附加偏壓降低Si-DLC膜層的表面粗糙度,提高膜層致密性。隨偏壓增大,Si-DLC膜沉積速率呈現(xiàn)先降低后增加的變化規(guī)律,先降低是由于原子氫化學(xué)刻蝕和Ar~+離子濺射占主導(dǎo)因素,后增加是由于工件自輝光放電增強(qiáng)乙炔的分解。膜層結(jié)構(gòu)的致密化和H含量的降低是提高Si-DLC膜力學(xué)性能的主要因素。Si-DLC膜納米硬度由8GPa升高到14GPa,-300V附加偏壓制備的Si-DLC膜具有較好的耐鋼球摩擦磨損性能。與常規(guī)籠形空心陰極沉積的Si-DLC單層膜相比,偏壓調(diào)控軟硬交替SiDLC多層膜結(jié)構(gòu),提高了膜層的整體韌性和膜基結(jié)合強(qiáng)度。316不銹鋼/SiDLC膜基體系劃痕結(jié)合力L_(C2)值由17 N升高到30N。同時,采用偏壓調(diào)控籠形空心陰極系統(tǒng),實(shí)現(xiàn)316不銹鋼氮化和偏壓調(diào)控多層Si-DLC膜連續(xù)制備,L_(C2)值提高到46N。隨多層膜厚度增大,高速鋼基體Si-DLC多層膜劃痕韌性值逐漸升高,厚度為35μm時達(dá)到2695,L_(C2)值達(dá)到112N。Si-DLC多層膜具有較低的摩擦系數(shù)和優(yōu)異的耐GCr15和Si C對磨球摩擦磨損性能。多層SiDLC膜熱穩(wěn)定性優(yōu)于常規(guī)籠形空心陰極技術(shù)制備的Si-DLC單層膜。偏壓調(diào)控和多層結(jié)構(gòu)設(shè)計增大了Si-DLC膜致密度,減少了膜層內(nèi)針孔缺陷,表現(xiàn)出優(yōu)異的耐15%HCl侵蝕能力。采用偏壓調(diào)控籠形空心陰極技術(shù),在硅片上成功制備厚度為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，

本文編號：2346726