立方氮化硼薄膜及溅射沉积的研究进展

溅射沉积由于获得的cBN薄膜颗粒尺寸小、立方相含量高,是cBN薄膜制备技术发展的一个重要方向。本文介绍了溅射沉积过程中的基体负偏压、沉积气氛、沉积温度、靶材功率等工艺参数对cBN薄膜中立方相的含量和薄膜性能的影响规律。并从优化沉积工艺参数、采用过渡层及在膜层中引入其它元素方面介绍了在降低膜层应力方面取得的研究进展。分析归纳出溅射沉积cBN薄膜目前存在的主要问题是薄膜应力过大、存在非立方相氮化硼及B、N原子的比例失配。提出了下一步研究工作的重点是通过深入认识溅射沉积cBN薄膜的的形成机理,优化沉积工艺参数及设计合理的过渡层和新型梯度涂层,以提高立方相的含量、保证B、N原子的比例、降低膜层应力。     

室温低压下脉冲等离子体生长立方氮化硼薄膜

运用脉冲高能量密度等离子体，在室温下制成立方氮化硼薄膜．沉积薄膜的衬底材料分别选用单晶硅、氯化钠和ＧＣｒ１５轴承钢，用扫描电镜、透射电镜、红外吸收谱仪、扫描Ａｕｇｅｒ微探针等对沉积的薄膜进行了分析与测试，结果表明，氮化硼薄膜的结构及性质强烈地依赖于实验条件．分析表明立方氮化硼晶核的形成与衬底材料关系不大，但晶核的生长则部分地依赖于衬底．     

立方氮化硼单晶——金刚石薄膜异质P—N结

本文在Ｓｉ掺杂Ｎ型片状立方氮化硼单晶（１１１）面上利用热灯丝化学汽相沉积方法生长了掺Ｂ的Ｐ型金刚石薄膜，从而制得了立方氮化硼单晶－金刚石薄膜异质Ｐ－Ｎ结，测试了该Ｐ－Ｎ结的Ｖ－Ａ特性，结果表明其整流特性良好。     

沉积温度对温度梯度法制备氮化硼薄膜结构和硬度的影响（英文）

采用温度梯度法,通过MW-ECR射频磁控溅射在硅片基底上制备了六方和立方混合的氮化硼薄膜。研究了薄膜的键结构,化学成分和力学性能。结果显示,对于氮化硼立方相的出现存在温度阈值,薄膜的硬度随沉积温度提高而提高。相对于传统薄膜制备方法,温度梯度方法具有更高的效率。     

Effects of Deposition Temperature on the Structure and Hardness of BN Films Prepared by a Gradient Temperature Method

采用温度梯度法,通过MW-ECR射频磁控溅射在硅片基底上制备了六方和立方混合的氮化硼薄膜。研究了薄膜的键结构,化学成分和力学性能。结果显示,对于氮化硼立方相的出现存在温度阈值,薄膜的硬度随沉积温度提高而提高。相对于传统薄膜制备方法,温度梯度方法具有更高的效率。     

立方氮化硼薄膜的制备与表征

在对国内外立方氮化硼薄膜的制备工艺及其表征方法进行了综述的基础上，分析了立方氮化硼膜制备中存在的问题，即薄膜的内应力高，结合强度低，沉积温度高，沉积速率低，沉积速率低，以及cBN中SP^3键含量不稳定。并提出了今后的研究方向：①cBN膜成核生长机理问题；②低温下大面积、高速生长的异质外延和定向生长问题；③膜基结合问题；④发展新的成膜技术，寻求无毒无污染的反应材料；⑤开发cBN膜的应用。     

室温低下脉冲等离子体生长立方氮化硼薄膜

运用脉冲高能量密度等离子体，在室温下制成立方氮化硼薄膜，沉积薄膜的衬底材料分别选用单昌硅，氯化钠和ＧＣｒ１５轴承钢，用扫描电镜，透射电镜，红外吸收谱仪，扫描Ａｕｇｅｒ微探针等对沉积的薄膜进行了分析与测试，结果表明，氮化硼薄膜的结构及性质强烈地依赖于实验条件。     

立方氮化硼薄膜的制备工艺

本文介绍了几种最新的立方氮化硼（Ｃ－ＢＮ）薄膜的制备工艺，并对薄膜中立方氮化硼相形成的影响因素进行了讨论。     

层状结构富Mg的Mg2Sn薄膜相组成与热电性能

利用高真空磁控溅射设备,通过顺序沉积制备富Mg的Mg2Sn热电薄膜。使用X射线衍射仪（XRD）、扫描电子显微镜（SEM）以及能谱仪（EDS）研究了沉积薄膜的物相组成、表面和截面形貌、元素含量及分布。使用塞贝克（Seebeck）系数/电阻分析系统LSR-3测量了沉积薄膜的电阻率和Seebeck系数,进而研究不同Mg含量的Mg2Sn薄膜的功率因子。结果表明,采用磁控溅射法可以制备出立方反萤石结构的Mg2Sn相薄膜,XRD显示,沉积薄膜是由立方结构的Mg2Sn相和少量的纳米尺寸的金属Mg相组成。随着Mg靶溅射时间的增加,纳米金属Mg相的含量增加,电阻率和Seebeck系数均表现为先升高后降低,这归因于少量纳米金属Mg相与基体相之间存在相界面。适量的金属Mg相存在于Mg2Sn薄膜中,有利于提高Seebeck系数。含有适量纳米尺寸金属Mg相的Mg2Sn沉积膜,因其Seebeck系数较高,电阻率适当,可获得较高的功率因子。层状结构的Mg2Sn薄膜可显著提高Seebeck系数,尽管电阻率也增加,但最终使薄膜的功率因子显著提高。     

科技文摘

超硬薄膜的制备——稻川幸之助,《金属表面技术》,1988.NO.2,P2-11(日文)本文阐述PVD 法、CVD 法和动态混合法制备硬质薄膜以及金刚石和立方氮化硼成膜的当前研究动态与发展。活性反应蒸镀、离子镀和溅射能够以高的沉积速率     

Effect of radio-frequency electric power applied to a boron nitride unbalanced magnetron sputter target on the deposition of cubic boron nitride thin film

Cubic boron nitride (c-BN) films were deposited by an unbalanced magnetron sputtering method. A (100) Si wafer with a nanocrystalline diamond thin film as a surface coating layer or that without it was used as a substrate. The target power was varied from 100 to 400 W. A boron nitride target was used, which was connected to a radio frequency power supply. High frequency power connected to a substrate holder was used for self-biasing. The deposition pressure was 0.27 MPa with a flow of Ar (18 sccm) — N₂ (2 sccm) mixed gas. The existence of threshold bias voltages for c-BN formation and resputtering were observed irrespective of target power. The bias voltage window for c-BN formation broadened with increased target power. The deposition rate decreased with enhanced bias voltage and decreased target power. Residual stresses of the films did not vary noticeably with target power within the target power range of c-BN formation. A parameter space for c-BN formation according to the target power and the bias voltage, as two variables, was suggested.     

Influence of nitrogen implantation into HSS substrate on internal stress and adhesion strength of c-BN films

Cubic boron nitride(c-BN) films were deposited on HSS substrate implanted with nitrogen ion by RF-magnetron sputtering. The films were analyzed by bending beam method, scratch test, XRD and AFM. The results show that the implantation of N ion can reduce the internal stress and improve the adhesion strength of the films.The critical load comes to 16.92N, compared to 1.75N of c-BN film on the unimplanted HSS. AFM shows that the surface of the c-BN film on the implanted HSS is low in roughness and small in grain size. The phase structure of the nitrogen implanted layer was analyzed by XRD. The influence of nitrogen implanted layer on the internal stress and adhesion strength of c-BN films were also investigated.     

离子源对中频反应磁控溅射AlN薄膜结构和性能的影响

采用离子源辅助中频反应磁控溅射技术在单晶硅及硬质合金基体上沉积AlN薄膜,利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度计、薄膜结合强度划痕试验仪等对薄膜结构及性能进行表征,着重研究了离子源对中频反应磁控溅射AlN薄膜结构和性能的影响.结果表明:离子源的辅助沉积有利于AlN相的合成,当离子源功率大于0.7 kW时,AlN沿(100)晶面择优取向明显,当离子源功率为1.3 kW时,所沉积膜层有向非晶化转变的趋势.同时,随着离子源功率的增加,所沉积的AlN薄膜致密度和膜、基结合力均显著提高,而膜层沉积速率和硬度则呈先上升后降低的规律.     

Synthesis of cubic boron nitride thin films by low-energy ion beam assisted deposition by applying substrate bias

Cubic boron nitride (c-BN) films are synthesized with low-energy ions of 100eV from a gridless ion gun by applying negative substrate bias. Boron is evaporated by an electron beam at rates of 0.8 to 2.3Å/sec onto silicon substrate. Substrate temperature and bias are varied from 400 to 800°C and from 0 to -700V, respectively. Due to the low-operating pressure of the ion beam assisted deposition (IBAD) process, applying substrate bias efficiently accelerates ions enough for synthesis of the c-BN phase. With increasing substrate bias, the major phase changes in the sequence of hexagonal boron nitride (h-BN) to c-BN to h-BN. The reappearance of the hexagonal phase at high bias voltage is thought to be due to the stress annealing effect. Intermediate temperatures have produced higher c-BN contents. Far-off stoichiometric film (N/B≈0.72) consists of h-BN phase even under the c-BN parameter but a little off stoichiometry has led to higher c-BN contents. The maximum contents of c-BN phase is about 70%. DC type bias and oxygen/hydrogen incorporation into the films are presumed to limit the content. The IBAD process with proper substrate bias is promising for large areas of and high rate growth of the c-BN phase.     

Laser ablation synthesis and characterization of nitride coatings

Thin film nitride coatings were deposited on Si (100) substrates by the pulsed laser deposition (PLD) technique. The PLD method is a unique process for depositing high quality thin films with novel microstructure and properties. Boron nitride (BN) films deposited on Si (100) substrates have a higher percentage of c-BN phases when processed in higher nitrogen partial pressure. Titanium nitride films deposited on Si (100) substrates at a higher temperature (600 °C) have better quality crystallinity and higher hardness and Young’s modulus values than films deposited at lower temperatures. Nanoindentation technique was used to measure the mechanical properties of thin films. The film orientation was determined by x-ray diffraction. Atomic force microscopy (AFM) technique was used to understand the growth structure of the films.     

硼膜多步骤注N的镀层结构研究

用离子束溅射硼靶，在W6o5Cr4V2钢上宙积一层硼膜，再用反冲注入法注氮以形成氮化硼（BN），注入时采用逐次递减能量（即50kV,30keV,10keV0的多步骤注入。用XPS分析膜的成分深度分布及元素的化学价态；用傅立叶红外（FTIR）反射谱分析膜的结构，结果表明：膜基界面产生混合，与用单一能量注入相比，多步骤注入时，膜层的N／B分布比较均匀；硼在膜中以BN形式存在，膜深度较大处为a-BN或h-BN，并且随着深度的降低，膜有向c-BN转化的趋势。     

Adhesion improvement of cubic boron nitride film on high speed steel substrate by BNX implanted buffer interlayer

One of the major problems for the deposition of cubic boron nitride(c-BN) films on W6Mo5Cr4V2 high speed steels(HHS) is the poor adhesion of the film to the substrate. For the purpose of improving adhesion, the BN_X implanted buffer layer was introduced between the HSS and c-BN film deposited by the RF-magnetron sputtering. The influence of the BN_X buffer layer on adhesion was investigated and the results showed that when the N/B ratio of the buffer layer is about 1:1, the adhesive strength of c-BN film to the HHS substrate reached the maximum, about 28.47 N, which is sixteen times higher than that of c-BN film deposited without the buffer layer. According to the XPS analysis, the surface of buffer interlayer was mainly in BN phase, which is the main reason to reduce the internal stress and improve the adhesion strength of c-BN films.     

DEPOSITION OF c-BN FILMS AND ADHESION IMPROVEMENT

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Synthesis and Characterization of Quenched and Crystalline Phases: Q-Carbon,Q-BN,Diamond and Phase-Pure c-BN

We report the synthesis and characterization of quenched (Q-carbon and Q-BN) and crystalline (diamond and c-BN) phases using a non-equilibrium technique. These phases are formed as a result of the melting and subsequent quenching of amorphous carbon and nanocrystalline h-BN in a super undercooled state by using high-power nanosecond laser pulses. Pulsed laser annealing also leads to the formation of nanoneedles, microneedles and single-crystal thin films of diamond and c-BN. This formation is dependent on the nucleation and growth times, which are controlled by laser energy density and thermal conductivities of substrate and as-deposited thin film. The diamond nuclei present in the Q-carbon structure (~ 80% sp³) can also be grown to larger sizes using the equilibrium hot filament chemical vapor deposition process. The texture of diamond and c-BN crystals is 〈111〉 under epitaxial growth and 〈110〉 under rapid unseeded crystallization. Our nanosecond laser processing opens up a roadmap to the fabrication of novel phases on heat-sensitive substrates.     

Stress Study on CrN Thin Films with Different Thicknesses on Stainless Steel

The reliability of a substrate curvature-based stress measurement method for CrN thin films on substrate with fluctuant surface was discussed. The stress error led by the ignorance of substrate thermal deformation was studied. Results showed that this error could be as large as several hundred MPa under general deposition conditions. Stress in the CrN thin films with different thicknesses ranging from 110 to 330 nm on stainless steel was studied by this method, in comparison with conventional results on silicon wafer. The thin films' morphology and structure were investigated and related to the film stress. A significant result of the comparison is that stress evolution in the thin films on steel obviously differs from that on silicon wafer, not only because the two substrates have different coefficients of thermal expansion, which provokes thermal stress, but also the considerable discrepancy in the thin films' grain coarsening rate and structure that induce different intrinsic stresses.