不同磁控溅射工艺对纳米晶TiN薄膜微观结构与力学性能的影响（英文）

对比研究了直流磁控溅射(dcMS)、高功率脉冲磁控溅射(HPPMS)和调制脉冲磁控溅射(MPPMS)所沉积纳米晶TiN薄膜的组织结构与力学性能。结果表明,因dcMS溅射粒子离化率与动能均较低,薄膜表现为存在少量空洞的柱状晶结构,薄膜力学性能差、沉积速率为51 nm/min。HPPMS因具有较高的瞬时离化率和较低的占空比,薄膜结构致密而光滑,性能得到了显著改善,但平均沉积速率较低,仅为25 nm/min。通过MPPMS技术可大范围调节峰值靶功率和占空比,从而得到较高的离化率和平均沉积速率,薄膜结构致密光滑、力学性能优异,沉积速率达45 nm/min,接近dcMS。     

双级HPPMS靶电流对TiN镀层微观结构及耐蚀性的影响

高功率脉冲磁控溅射（HPPMS）利用较高的脉冲峰值靶功率密度（如：1-3kW/cm2）获得高密度的等离子体,可提高TiN镀层的微观结构和力学性能。然而,HPPMS技术的主要缺点是平均沉积速率较低,增加了镀层的制备成本。为了解决传统HPPMS平均沉积速率低的问题,研究提出一种新型的双级HPPMS技术,即在一个脉冲周期内具有两个连续的、独立可调的脉冲阶段。通过对双级HPPMS电场的合理调配,可制备得到结构致密的TiN镀层,研究了双级HPPMS靶电流对TiN镀层微观结构及耐蚀性的影响。结果表明,当靶电流增大至20A时,靶面形貌由小凹坑转变为大面积凹坑,说明镀料粒子的脱靶方式由碰撞溅射转变为升华或蒸发。同时,当靶电流为10A时,镀层颗粒呈现三棱锥状结构,平均晶粒尺寸为11nm;当靶电流增大至25A时,镀层颗粒呈现光滑致密的圆胞状结构,平均晶粒尺寸为18nm,光滑致密的组织结构使镀层具有较好的耐蚀性。     

高功率脉冲磁控溅射技术的离子(粒子)特性及其对薄膜组织结构的影响

作为电离物理气相沉积法(I-PVD)家族的新成员,高功率脉冲磁控溅射技术(HPPMS/HiPIMS)由于其较高的电子密度及金属离化率,自发现以来即受到了国内外专家的广泛关注。从高功率脉冲磁控溅射过程中金属离化率的角度出发,对高功率脉冲磁控溅射技术的离化机制、离化率定义进行了概述。在此基础上,重点综述了近些年来常用的离化率测量方法,包括等离子体发射光谱法、原子吸收光谱法、质谱仪法、多栅式石英微天平法、正电压沉积法等,并比较了各方法之间的优劣。进一步归纳了影响离化率的关键因素,如靶材功率、脉宽、频率、占空比、峰值电流等电学参数以及靶材种类、气体压力、磁场等非电参数。最后,针对离化率对薄膜性能的影响等方面的研究进展进行了综述,分别讨论了离化率对薄膜组织结构、斜入射沉积及均一性的影响,并概述了离化率对薄膜性能的不利影响。该文旨在为更好地调控并优化溅射过程中的离子特性提供借鉴,为制备性能优异的薄膜提供理论基础。     

调制脉冲磁控溅射峰值靶功率密度对纯Ti镀层沉积行为的影响

调制脉冲磁控溅射可通过改变强/弱离化阶段的脉冲强度和占空比等电场参量,大幅调控镀料粒子的离化率、沉积能量和数量,可实现对沉积镀层形核与生长过程的精确把控。本文在非平衡闭合磁场条件下,采用调制脉冲磁控溅射技术,通过对其强离化脉冲阶段的脉冲宽度和靶功率进行调控获得持续增大的峰值靶功率密度,并在此条件下制备多组纯Ti镀层,对其微观形貌和力学性能进行了检测分析。研究结果表明,当强离化脉冲阶段的峰值靶功率密度由0.15 kW×cm-2持续增大至0.86 kW×cm-2时,所制备的纯Ti镀层具有11nm的平均晶粒尺寸、较其他峰值靶功率密度条件下制备镀层更为致密的组织结构、平整的表面质量（表面粗糙度Ra为11nm）和良好的力学性能。     

双脉冲磁控溅射峰值靶电流密度对TiN薄膜结构与力学性能的影响

自主研发了双脉冲磁控溅射技术,提出在一个脉冲周期内电流呈阶梯式上升的双脉冲电场设计理念,通过对2个脉冲阶段持续时间和峰值靶电流密度的调配,既满足提高镀料粒子动能与离化率以制备高性能薄膜的工艺要求,又达到增加脉冲持续时间以提高薄膜沉积速率的效能目标。采用双脉冲磁控溅射技术,在后期脉冲阶段的不同峰值靶电流密度下制备4组TiN薄膜,研究了峰值靶电流密度对薄膜微观结构和力学性能的影响。结果表明,将峰值靶电流密度提高至0.87 A/cm~2时,所制备的TiN薄膜呈现出颗粒细小且致密的组织,平均晶粒尺寸为17 nm。同时,薄膜的显微硬度和膜基结合力可分别达29.5 GPa和30.0 N。     

高功率脉冲磁控溅射制备非晶碳薄膜研究进展

非晶碳薄膜主要由sp3碳原子和sp2碳原子相互混杂的三维网络构成,具有高硬度、低摩擦系数、耐磨损、耐腐蚀以及化学稳定性等优异性能。然而传统制备方法难以实现薄膜结构及其性能的综合调控,高功率脉冲磁控溅射因其离子沉积特性受到领域内专家学者的关注。总结了近年来关于高功率脉冲磁控溅射制备非晶碳薄膜材料的研究进展。重点介绍了高功率脉冲磁控溅射石墨靶的放电特性,指出了其在沉积非晶碳薄膜过程中获得高碳原子离化率的条件。针对离化率和沉积速率低,主要从提高碳原子离化率和碳离子传输效率等角度,介绍了几种改进的高功率脉冲磁控溅射方法。并对比了不同高功率脉冲磁控溅射方法中的碳原子离化特征、薄膜沉积速率、结构和力学性能。进一步地,探讨了高功率脉冲磁控溅射在制备含氢非晶碳薄膜和金属掺杂非晶碳薄膜中的优势及其在燃料电池、生物、传感等前沿领域的应用。最后,对高功率脉冲磁控溅射石墨靶的离子沉积特性、非晶碳薄膜制备及其应用研究趋势进行了展望。     

调制脉冲磁控溅射峰值靶功率密度对纯Ti镀层沉积行为的影响（英文）

调制脉冲磁控溅射可通过改变强、弱离化阶段的脉冲强度和占空比等电场参量,大幅调控镀料粒子的离化率、沉积能量和数量,实现对沉积镀层形核与生长过程的精确把控。在非平衡闭合磁场条件下,采用调制脉冲磁控溅射技术,通过对其强离化脉冲阶段的脉冲宽度和靶功率进行调控获得持续增大的峰值靶功率密度,并在此条件下制备多组纯Ti镀层,对其微观形貌和力学性能进行了检测分析。结果表明,当强离化脉冲阶段的峰值靶功率密度由0.15 k W·cm-2持续增大至0.86 k W·cm~(-2)时,所制备的纯Ti镀层具有11 nm的平均晶粒尺寸,且较其他峰值靶功率密度条件下的制备镀层具有更为致密的组织结构、平整的表面质量(表面粗糙度Ra为11 nm)和良好的力学性能。     

双级高功率脉冲磁控溅射N2流量对TiN镀层结构及性能的影响

研究提出一种新型的双级高功率脉冲磁控溅射技术,通过合理调配双级脉冲电场参数在不同N2流量条件下制备了TiN镀层并对其微观结构及性能进行分析。结果表明,随着N2流量由10 sccm逐渐增加至40 sccm时,TiN镀层的择优取向由（111）晶面逐渐转变为（220）晶面、表面形貌由多方向棱角的锥状结构转变为紧密结合的圆胞状结构,镀层均呈现柱状晶的生长方式且平均晶粒尺寸为纳米级,当氮气流量为20 sccm时镀层N/Ti原子比最接近标准值1,镀层组织结构最为致密且具有最优的力学性能和膜基结合性能;同时,利用新型的双级高功率脉冲磁控溅射技术可有效改善传统高功率脉冲磁控溅射平均沉积速率较低的技术缺憾,当N2流量为20 sccm时可达到46.35 nm/min。     

脉冲频率对HiPIMS制备TiN薄膜组织和力学性能的影响EI北大核心CSCD

为探究脉冲频率对通过高功率脉冲磁控溅射制备TiN薄膜组织力学性能的影响,选用Ti靶和N2气体,采用反应磁控溅射技术通过改变高功率脉冲磁控溅射(HiPIMS)电源脉冲频率在Si(100)晶片上制备不同种TiN薄膜。利用X射线衍射仪(XRD)、X射线光电子能谱仪和扫描电子显微镜(SEM)对所制薄膜晶体结构和成分、表面和断面形貌进行分析,利用纳米压痕仪对薄膜的硬度和弹性模量进行表征,并计算H/E和H^(3)/E^(2)。结果表明,高离化率Ti离子轰击促使薄膜以低应变能的晶面优先生长,所制TiN薄膜具有(111)晶面择优取向。薄膜平均晶粒尺寸均在10.3 nm以下,随着脉冲频率增大晶粒尺寸增大,结晶度和沉积速率降低,柱状生长明显,致密度下降,影响薄膜力学性能。在9 kHz时,TiN薄膜的晶粒尺寸可达8.9 nm,薄膜组织致密具有最高硬度为30 GPa,弹性模量374 GPa,弹性恢复为62.9%,具有最优的力学性能。     

高功率脉冲磁控溅射轮辐特征等离子体研究综述EI北大核心CSCD

高功率脉冲磁控溅射技术(HiPIMS)是最新一代磁控溅射技术,高度离化的脉冲等离子体是HiPIMS技术的核心特征。针对HiPIMS放电轮辐特征,评述特征放电下HiPIMS等离子体测量、模拟及对薄膜生长作用的最新研究进展。较之常规磁控溅射技术,HiPIMS溅射靶材粒子高度离化,等离子体阻抗显著降低。等离子体在靶材表面形成以千米每秒速度旋转漂移的致密等离子体结构,存在局域化和自组织特征,可显著影响沉积粒子输运行为,为沉积薄膜生长提供一个新的控制维度。HiPIMS放电轮辐一般呈现扩散形和三角形两种形态,通过介绍轮辐变化规律、形成机制的进展,明确靶材溅射产额也对其形态有影响。另一方面,HiPIMS轮辐结构结合其脉冲放电特点,可控制薄膜沉积通量输运特征,进而影响沉积薄膜的微结构、表面粗糙度等表面完整性参数。具有微秒到毫秒跨尺度多级脉冲调节能力的高功率调制脉冲磁控溅射(MPPMS)和高功率深振荡脉冲磁控溅射(DOMS),脉冲控制跨时间尺度特性带来的轮辐特征可剪裁性,为在更大时间和空间维度上薄膜生长控制提供了可能性。     

High power pulsed magnetron sputtering: A review on scientific and engineering state of the art

High power pulsed magnetron sputtering (HPPMS) is an emerging technology that has gained substantial interest among academics and industrials alike. HPPMS, also known as HIPIMS (high power impulse magnetron sputtering), is a physical vapor deposition technique in which the power is applied to the target in pulses of low duty cycle (< 10%) and frequency (< 10 kHz) leading to pulse target power densities of several kW cm^− 2. This mode of operation results in generation of ultra-dense plasmas with unique properties, such as a high degree of ionization of the sputtered atoms and an off-normal transport of ionized species, with respect to the target. These features make possible the deposition of dense and smooth coatings on complex-shaped substrates, and provide new and added parameters to control the deposition process, tailor the properties and optimize the performance of elemental and compound films.     

Recent advances in modulated pulsed power magnetron sputtering for surface engineering

Over the past 10 years, the development of high-power pulsed magnetron sputtering (HPPMS) has shown considerable potential in improving the quality of sputtered films by generating a high degree of ionization of the sputtered species to achieve high plasma density by using pulsed, high peak target power for a short period of time. However, the early HPPMS technique showed a significantly decreased deposition rate as compared to traditional magnetron sputtering. Recently, an alternative HPPMS deposition technique known as modulated pulsed power (MPP) magnetron sputtering has been developed. This new sputtering technique is capable of producing a high ionization fraction of sputter target species and while at the same time achieving a high deposition rate. This paper is aimed at giving a review of recent advances in the MPP technique in terms of the plasma properties, the improvements in the structure and properties of the thin films, and the important advances in the high rate deposition of high quality thick coatings on the order of 20–100 μm in thickness.     

The structure and properties of chromium nitride coatings deposited using dc, pulsed dc and modulated pulse power magnetron sputtering

The time averaged ion energy distributions and ion fluxes of continuous dc magnetron sputtering (dcMS), middle frequency pulsed dc magnetron sputtering (PMS), and modulated pulse power (MPP) magnetron sputtering plasmas were compared during sputtering of a Cr target in an Ar/N₂ atmosphere in a closed field unbalanced magnetron sputtering system. The results showed that the dcMS plasma exhibited a low ion energy and ion flux; the PMS plasma generated a moderate ion flux of multiple high ion energy regions; while the MPP plasma exhibited a significantly increased number of target Cr⁺ and gas ions with a low ion energy as compared to the dcMS and PMS plasmas. Cubic CrN coatings were deposited using these three techniques with a floating substrate bias. The structure and properties of the coatings were characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nanoindentation, microscratch and ball-on-disk wear tests. It was found that the deposition rate of the MPP CrN depositions was slightly lower than those of the dcMS depositions, but higher than in the PMS depositions at similar average target powers. The coatings deposited in the dcMS and PMS conditions without the aid of the substrate bias exhibited large columnar grains with clear grain boundaries. On the other hand, the interruption of the large columnar grain growth accompanied with the renucleation and growth of the grains was revealed in the MPP CrN coatings. The MPP CrN coatings exhibited a dense microstructure, fine grain size and smooth surface with high hardness (24.5 and 26 GPa), improved wear resistance (COF = 0.33 and 0.36) and adhesion, which are the results of the low ion energy and high ion flux bombardment from the MPP plasma.     

Process stabilization and enhancement of deposition rate during reactive high power pulsed magnetron sputtering of zirconium oxide

Reactive high power pulsed magnetron sputtering (HPPMS) of zirconium oxide exhibits a stable and hysteresis-free transition zone, as opposed to reactive direct current magnetron sputtering (dcMS). The stabilization of the transition zone in HPPMS facilitates the growth of transparent zirconium oxide films at lower target coverage, in comparison to dcMS. The lower target coverage, in turn, allows for film deposition rates up to 2 times higher than those achieved by dcMS. The mechanisms which lead to the process stabilization in reactive HPPMS are discussed.     

高功率脉冲磁控溅射沉积原理与工艺研究进展*

高功率脉冲磁控溅射技术是一种峰值功率超过平均功率2个量级、溅射靶材原子高度离化的脉冲溅射技术,作为一种新的离子化物理气相沉积技术,已成为国际研究的热点,有关高功率脉冲放电、等离子体特性、薄膜及其工艺等方面的研究进展十分迅速。文中从高功率脉冲磁控溅射的原理出发,介绍10多年来高功率脉冲电源的发展,从高功率脉冲放电等离子体特性与放电物理、等离子体模型,以及沉积速率和薄膜特性等方面综述技术的研究进展。