氧化硅/氧化铁复合磨粒用于硬盘基片的抛光研究

本文以HNO3、NaOH、Fe(NO3)3和SiO2浆料为原料,采用沉淀法制备了1种SiO2/Fe2O3复合磨粒,通过X射线衍射仪(XRD)、飞行时间二次离子质谱仪(TOF-SIMS)和扫描电子显微镜(SEM)对其结构进行表征,结果表明Fe2O3包覆到SiO2的表面,复合粒子具有很好的分散性.用UNIPOL-1502抛光机研究了所制备复合磨粒在镍磷敷镀的硬盘基片中的抛光性能,抛光后硬盘基片的表面粗糙度Ra由抛光前的8.87nm降至3.73nm;抛光后表面形貌的显微镜观测结果表明新制备的复合磨粒表现出较好的抛光性能.     

Investigation of non-diamond carbon phases and optical centers in thermochemically polished polycrystalline CVD diamond films

Polycrystalline chemical vapor deposition (CVD) diamonds films grown on silicon substrates using the microwave-enhanced CVD technique were polished using the thermochemical polishing method. The surface morphology of the samples was determined by optical and scanning electron microscopes before and after polishing. The average surface roughness of the as-grown films determined by the stylus profilometer yielded 25 μm on the growth side and about 7 μm on the substrate side. These figures were almost uniform for all the samples investigated. Atom force microscopic measurements performed on the surface to determine the average surface roughness showed that thermochemical polishing at temperatures between 700 °C and 900 °C reduced the roughness to about 2.2 nm on both the substrate and growth sides of the films. Measurements done at intermittent stages of polishing using confocal micro-Raman spectroscopy showed that thermochemical polishing is accompanied by the establishment of non-diamond carbon phases at 1353 cm⁻¹ and 1453 cm⁻¹ at the initial stage of polishing and 1580 cm⁻¹ at the intermediate stage of polishing. The non-diamond phases vanish after final fine polishing at moderate temperatures and pressures. Photoluminescence of defect centers determined by an Ar⁺ laser (λl_exct= 514.532 nm) showed that nitrogen-related centers with two zero-phonon lines at 2.156 eV and 1.945 eV and a silicon-related center with a zero-phonon line at 1.681 eV are the only detectable defects in the samples. Received: 26 July 1999 / Accepted: 15 November 1999     

ZnSe多晶化学机械抛光研究

本文针对ZnSe多晶的性能,在试验的基础上,研究出一套实用的、行之有效的ZnSe多晶加工工艺,并重点讨论了化学机械抛光工艺.同时对加工后零件的工艺参数、表面质量及透过率的测试,结果表明所采用的化学机械加工法可取得非常好的抛光效果.     

LBO晶体超光滑表面抛光机理

胶体SiO2抛光LBO晶体获得无损伤的超光滑表面,结合前人对抛光机理的认识,探讨了超光滑表面抛光的材料去除机理,分析了化学机械抛光中的原子级材料去除机理.在此基础上,对胶体SiO2抛光LBO晶体表面材料去除机理和超光滑表面的形成进行了详细的描述,研究抛光液的pH值与材料去除率和表面粗糙度的关系.LBO晶体超光滑表面抛光的材料去除机理是抛光液与晶体表面的活泼原子层发生化学反应形成过渡的软质层,软质层在磨料和抛光盘的作用下很容易被无损伤的去除.酸性条件下,随抛光液pH值的减小抛光材料的去除率增大;抛光液pH值为4时,获得最好的表面粗糙度.     

6H-SiC衬底片的表面处理

相比于蓝宝石,6H-SiC是制作GaN高功率器件更有前途的衬底.本文研究了表面处理如研磨、化学机械抛光对6H-SiC衬底表面特性的影响.用显微镜、原子力显微镜、拉曼光谱、卢瑟福背散射谱表征了衬底表面.结果表明经过两步化学机械抛光后提高了表面质量.经第二步化学机械抛光后的衬底具有优异的表面形貌、高透射率和极小的损伤层,其表面粗糙度RMS是0.12nm.在该衬底上用MOCVD方法长出了高质量的GaN外延膜.     

Experimental investigation of the parameter dependency of the removal rate of thermochemically polished CVD diamond films

Parameters controlling the removal rate of chemical vapor deposition (CVD) diamond films thermochemically polished on transition metals in a mixed argon-hydrogen atmosphere were investigated. The ambient temperature, the pressure exerted on the diamond film, the angular velocity of the polishing plate, the frequency and the amplitude of the transverse vibrations were among the parameters used in the experiments. Temperature measurements showed that the removal rate was increased exponentially with increasing magnitude of the parameter. An exponential increase in the removal rate was also observed with increasing pressure and hence with increasing contact between the diamond film and the polishing plate. However, an exponential decrease in the removal rate was observed with increasing angular velocity of the polishing plate. The removal rate obtained with the application of transverse vibrations was more than three times that obtained without transverse vibrations. Moreover, the removal rate was seen to be higher at resonant frequencies. An increase in the removal rate with increasing amplitude of the transverse vibrations was also observed. Raman measurements carried out on the films to determine the presence of the non-diamond carbon layer after thermochemical polishing revealed non-diamond Raman lines only for films polished at 1000 °C and 1050 °C for the temperature range 750–1050 °C. Received: 27 October 1999 / Accepted: 2 February 2000     

环境友好助洗剂——4A沸石

介绍了4A沸石的结构、性质及其作为洗涤助剂等方面的应用和国内外发展状况。     

基于摩擦磨损的KDP晶体固结磨料抛光垫优化

本文通过固结磨料球与KDP晶体对磨的单因素试验探究固结磨料球中反应物种类、磨粒浓度、反应物浓度、基体硬度对摩擦系数、磨痕截面积和磨痕处粗糙度的影响,试验结果表明:KHCO₃固结磨料球对磨后磨痕对称性好,磨痕处的粗糙度值低;磨痕截面积随磨粒和反应物浓度的增加而增大,随基体硬度的增大而降低;磨痕处粗糙度随磨粒和反应物浓度的增加先降低后上升,随基体硬度的增大先上升后降低;摩擦系数受磨粒和反应物浓度影响不明显,随基体硬度的增大而降低。选择KHCO₃作为反应物,Ⅰ基体,磨粒浓度为基体质量的100%,反应物浓度为15%制备固结磨料球与KDP晶体对磨后的磨痕轮廓对称度好且磨痕处粗糙度值低,以该组分制备固结磨料垫干式抛光KDP晶体,可实现晶体表面粗糙度Sa值为18.50 nm,材料去除率为130 nm/min的高效精密加工。     

机械磨抛对CdZnTe薄膜阻变特性的影响

采用磁控溅射法在ITO玻璃上制备了CdZnTe薄膜,探究机械磨抛对CdZnTe薄膜阻变特性的影响。通过对XRD图谱、Raman光谱、AFM显微照片等实验结果分析阐明了机械磨抛影响CdZnTe薄膜阻变特性的物理机制。研究结果表明,磁控溅射制备的薄膜为闪锌矿结构,F43m空间群。机械磨抛提高了CdZnTe薄膜的结晶质量;CdZnTe薄膜粗糙度(Ra)由磨抛前的3.42 nm下降至磨抛后的1.73 nm;磨抛后CdZnTe薄膜透过率和162 cm^-1处的类CdTe声子峰振动峰增强;CdZnTe薄膜的阻变开关比由磨抛前的1.2增加到磨抛后的4.9。机械磨抛提高CdZnTe薄膜质量及阻变特性的原因可能是CdZnTe薄膜在磨抛过程中发生了再结晶。     

半球蓝宝石整流罩制造技术研究

整流罩在高速飞行中既要对空气进行整流,同时又起光学窗口的作用。蓝宝石材料硬度高,加工非常困难。分别从精磨模、精磨磨料、抛光膜层、抛光辅料、机床速度和压力等方面介绍了一种加工蓝宝石整流罩的工艺方法。