硒化镉晶片的化学机械抛光

硒化镉(CdSe)的表面加工质量对CdSe基器件的性能至关重要.化学机械抛光(CMP)是一种获得高质量晶体加工表面的常用方法.为改善CdSe晶片的表面加工质量,以SiO2水溶胶配制抛光液,研究了抛光液磨料质量分数、抛光液pH值、氧化剂NaClO的质量分数、抛光盘转速和抛光时间等因素对CdSe晶片抛光去除速率和表面质量的影响,优化了CdSe的CMP工艺参数.结果表明,在优化工艺条件下,CdSe的平均去除速率为320 nm/min,晶片的抛光表面无明显划痕和塌边现象.原子力显微镜(AFM)测量结果表明,抛光后的CdSe晶片表面粗糙度为0.542 nm,可以满足器件制备要求.     

SiC化学机械抛光技术的研究进展

介绍了半导体材料SiC抛光技术的发展及直接影响器件成品率的衬底材料几何参数和表面质量因素.讨论了SiC化学机械抛光方法(CMP),包括磨削、粗抛和精抛三个过程,其中粗抛又分重压和轻压两个过程,通过这种方法能够制造出平整度好,表面低损伤的SiC晶片的抛光片,切割线痕通过磨削和抛光可以有效地去除,最终达到表面粗糙度小于1 nm.分析了CMP的原理和相关工艺参数对抛光的影响,指出了其发展前景.     

SiC(0001)面和(000-1)面CMP抛光对比研究

研究了SiC衬底(0001)面和(000-1)面不同的CMP抛光特性.分别采用pH值为10.38和1.11的改性硅溶胶抛光液对SiC衬底的(0001)Si面和(000-1)C面进行对比抛光实验.使用精密天平测量晶片抛光前后的质量,计算出CMP抛光工艺的材料去除速率.并使用强光灯、微分干涉显微镜和原子力显微镜检测晶片表面质量.发现采用酸性抛光液和碱性抛光液进行抛光,均有Vc＞Vsi;而对于(0001) Si面,有Vsi 酸＞Vsi碱;对于(000-1)C面,有Vc酸＞Vc碱.该结论对于探索最佳碳化硅的CMP抛光工艺具有较高价值.     

SiC(0001)面和(000-1)面CMP抛光对比研究

研究了SiC衬底(0001)面和(000-1)面不同的CMP抛光特性。分别采用pH值为10.38和1.11的改性硅溶胶抛光液对SiC衬底的(0001)Si面和(000-1)C面进行对比抛光实验。使用精密天平测量晶片抛光前后的质量,计算出CMP抛光工艺的材料去除速率。并使用强光灯、微分干涉显微镜和原子力显微镜检测晶片表面质量。发现采用酸性抛光液和碱性抛光液进行抛光,均有VC>VSi;而对于(0001)Si面,有VSi酸>VSi碱;对于(000-1)C面,有VC酸>VC碱。该结论对于探索最佳碳化硅的CMP抛光工艺具有较高价值。     

热释电探测器PZT晶片制备工艺研究

介绍了热释电探测器PZT晶片制备工艺及选择锆钛酸铅(PZT)陶瓷材料制作敏感元的理论依据,阐述了晶片磨抛理论,对磨抛质量影响因素进行了细致分析。对比了几种抛光液对晶片表面的抛光效果,并进行了扫描电镜和表面粗糙度分析,得到了抛光后晶片表面的扫描电子显微镜(SEM)照片和晶片表面形态,确定了最佳抛光材料。通过理论和实践的结合,研制出了完全能满足器件工艺要求的热释电探测器晶片。     

GLSI多层布线钨插塞CMP表面质量的影响因素分析

随着超大规模集成电路向高集成、高可靠性及低成本的方向发展,对IC工艺中的全局平坦化提出了更高的要求。在特大规模集成电路(GLSI)多层布线化学机械抛光(CMP)过程中,抛光质量对器件的性能有明显影响。研究了多层互连钨插塞材料CMP过程中表面质量的影响因素及控制技术,分析了抛光过程中影响抛光质量的主要因素,确定了获得较高去除速率和较低表面粗糙度的抛光液配比及抛光工艺参数。     

常γ电调管材料质量影响因素的探讨

本文报道了GaAs常γ电调变容管材料的研究.文中分析了GaAs单晶衬底的质量对外延层表面形貌和外延层-衬底间界面状态的影响;研究了外延工艺条件与外延层浓度分布的关系;讨论了外延层载流子浓度分布对器件C-V特性的影响.文中还给出了材料的制管结果.     

硅片的化学减薄

硅衬底的质量直接影响外延层质量和器件的性能.一般要求外延前的衬底具备:(1)无或极少量机械损伤;(2)小的弯曲度;(3)高度平整光洁的抛光表面,且抛光表面的损伤应力尽量小.这三者是相互制约的.众所周知,晶体经切割、研磨之后会引入大量的机械损伤.据报道,损伤层的厚度在50μ以上,其中多晶层为2～3μ,裂纹层20μ,弹性畸变层为30μ左右.其中弹性畸变是由应力引起的,较深.单用抛光方法去除50μ以上的损伤层,需要6小时,难以达到良好的平整度,也是不经济的.化学减薄既能除去衬底原有的表面损     

热释电探测器PZT晶片制备工艺研究

介绍了热释电探测器PZT晶片制备工艺及选择锆钛酸铅（PZT）陶瓷材料制作敏感元的理论依据,阐述了晶片磨抛理论,对磨抛质量影响因素进行了细致分析。对比了几种抛光液对晶片表面的抛光效果,并进行了扫描电镜和表面粗糙度分析,得到了抛光后晶片表面的扫描电子显微镜（SEM）照片和晶片表面形态,确定了最佳抛光材料。通过理论和实践的结合,研制出了完全能满足器件工艺要求的热释电探测器晶片。     

不同抛光参数对蓝宝石衬底CMP质量的影响

蓝宝石衬底化学机械抛光(CMP)质量直接影响器件的成品率和可靠性。抛光液和抛光工艺参数是影响CMP质量的决定性因素。为了得到更优的抛光液利用率以及更好的抛光效果,系统研究了自主研制的抛光液pH值、抛光压力、转速和流量等抛光参数对c面蓝宝石衬底化学机械抛光去除速率和表面粗糙度的影响。结果表明,去除速率随pH值、抛光压力、转速和流量的升高先增加后减小;表面粗糙度随pH值、抛光压力、转速的升高先减小后增加,随流量升高而慢慢降低。通过实验进行优化,当pH值为10.5、抛光压力为27.6 kPa、抛光头转速为40 r/min、抛光盘转速为45 r/min、流量为160 mL/min时,去除速率能稳定在2.69 μm/h,表面粗糙度为0.184 nm。此规律对指导工业生产具有重要的意义。     

Development of a Method for Chemical–Mechanical Preparation of the Surface of CdZnTe Substrates for HgCdTe-Based Infrared Focal-Plane Arrays

This paper reports the first implementation in our laboratory of a chemical–mechanical polishing (CMP) process for CdZnTe (CZT) substrates prepared for growth of HgCdTe layers by liquid phase epitaxy and molecular beam epitaxy. The process enables significant reduction of the thickness of the damaged zone induced by the mechanical polishing that must be etched away before epitaxy. Resulting improvements in surface morphology, in terms of waviness and density of point defects, are reported. The chemical state of surfaces polished by CMP was characterized by x-ray photoelectron spectroscopy. The chemical state was highly homogeneous; comparison with a reference surface is reported. End use assessment of this surface processing was compared with that of reference substrates by preparation of focal-plane arrays in the medium-wavelength infrared spectral range, by using epitaxial layers grown on substrates polished by different methods. The electro-optical performance of the detectors, in terms of photovoltaic noise operability, are reported. The results reveal that the state of this CMP surface is at the level of the best commercial substrates.     

Chemical mechanical polishing of polymeric materials for MEMS applications

Polymeric materials such as polycarbonate (PC) and poly-methyl methacryate (PMMA) are replacing silicon as the major substrate in microfluidic system fabrication due to their outstanding features such as low cost and good chemical resistance. In this study, chemical mechanical polishing (CMP) of PC and PMMA substrates was investigated. Four types of slurry were tested on CMP of the polymers under the same process conditions. The slurry suitable for polishing PC and PMMA was then chosen, and further CMP experiments were carried out under different process conditions. Experimental results showed that increasing table speed or head load increased the material removal rates of the polymers. The polymeric surface quality after CMP was acceptable to most MEMS applications. Analysis of variance was also carried out, and it was found that the interaction of head load and table speed had a significant (95% confidence) effect on surface finish of polished PMMA. On the other hand, table speed had a highly significant (99% confidence) effect on surface finish of polished PC.     

Effect of Nano-sized CeO2 Abrasives on Chemical Mechanical Polishing of Silicon Wafer

The conception of the soft layer during chemical mechanical polishing（CMP） was proposed for the first time. The soft layer was a reaction layer formed on the silicon surface; it was softer than the silicon substrate and its thickness was about several nanometers. The existence of the soft layer could increase the material volume removed by one particle and increase the material removal rate during CMP. At the same time, the soft layer could decrease the cutting depth of the abrasive particle so as to realize ductile grinding, and it is useful to decrease the roughness of the polished surface and to improve the polishing quality.     

软脆碲锌镉衬底的新型化学抛光技术研究

碲锌镉(CdZnTe)是液相外延碲镉汞(HgCdTe)薄膜的最佳衬底材料。获得高质量的CdZnTe衬底表面对于提升红外探测器的性能有着十分重大的意义。针对CdZnTe表面加工技术进行了研究,开发出一种新的化学抛光技术,使得抛光后的CdZnTe表面粗糙度Ra可达0.3 nm。     

一种适合SOI全介质隔离电路的平坦化技术

介绍了一种适合制作SOI全介质隔离电路的平坦化技术。该技术采用外延多晶硅回填隔离槽，并结合化学机械抛光，使SOI全介质隔离完成后形成的表面能达到单晶硅抛光材料的水平。该工艺适合制作某些具有特殊要求的集成电路、MEMS器件构件以及将电路和MEMS构件集成在同一硅片上的一体化加工。     

硅晶片化学机械抛光中的化学作用机理

通过分析硅晶片化学机械抛光过程中软质层的形成及其对材料去除过程的影响,研究了使用纳米CeO2磨料进行化学机械抛光中的化学作用机理.分析表明,软质层是抛光液与硅晶片反应形成的一层覆盖在硅基体表面的腐蚀层,其硬度比基材小,厚度大约在几个纳米.软质层的存在一方面增大单个磨料所去除材料的体积,增加材料去除速率;另一方面减小了磨料嵌入硅晶片基体的深度,这对于实现塑性磨削,降低抛光表面粗糙度,都起着重要的作用.     

碱性抛光液在CMP过程中对低k介质的影响

以p型111硅片为衬底,经过旋涂固化制备低介电常数(低k)材料聚酰亚胺。经过化学机械抛光(CMP)过程,考察实验前后低k材料介电性能的变化。实验中分别使用阻挡层抛光液、Cu抛光液以及新型抛光液对低k材料进行抛光后,利用电参数仪对低k材料进行电性能测试。结果显示,低k材料介电常数经pH值为7.09新型抛光液抛光后,k值由2.8变为2.895,漏电流在3.35 pA以下,去除速率为59 nm/min。经新型抛光液抛光后的低k材料,在电学性能等方面均优于阻挡层抛光液和Cu抛光液,抛光后的低k材料的性能能够满足应用要求。     

Newly-developed InP wafers for epitaxial growth from Nikko Kyodo Co Ltd

To meet the present and future needs for epitaxial growth of advanced electronic and optoelectronic devices, Nikko Kyodo (formerly Nippon Mining) has its own program for developing and improving its InP materials. This technical and quality program encompasses all aspects of process technology including the company's own in-house MOVPE and MBE facilities. As part of our coverage for the InP and Related Materials Conference in Paris, this article updates Nikko Kyodo's progress in the development of the surface quality of InP polished wafers.     

An effort in planarising microwave plasma CVD grown polycrystalline diamond (PCD) coated 4 in. Si wafers

Large area CVD grown diamond coatings should have very smooth surface in many of its applications, like microwave power transmission windows etc. Combination of mechanical and chemical forces during polishing helps to achieve desired surface roughness of the polycrystalline diamond (PCD) coatings. Authors report the variation of pressure, slurry feeding rate, addition of chemicals and the time of polishing to observe the efficiency of chemo-mechanical polishing (CMP) technique in planarising CVD diamond material grown over 100 mm diameter silicon wafers. PCD were found to be polished by bringing down the as-grown surface roughness from 1.62 µm to 46 nm at some points on large areas. One coherence scanning interferometer was used to check the roughness at different stages of CMP. Raman spectroscopy was used to evaluate the polished PCD samples in terms of their quality, internal stress at different positions on the same wafer surface after CMP process. It was found that the well polished regions were of better quality than the less polished regions on the same wafer surface. But due to coating non-uniformity of the deposited PCD grown by microwave plasma CVD over large area, CMP could not produce uniform surface roughness over the entire 100 mm diameter wafer surface. We concluded that CMP could effectively but differentially polish large area PCD surfaces, and further process improvements were needed.