蓝宝石衬底片化学机械抛光的研究

为了提高蓝宝石化学机械抛光（CMP）效果，对其抛光工艺进行了研究。采用SiO2磨料对蓝宝石衬底片进行抛光，分析了抛光时的温度、pH条件、磨料粒径及浓度，结果表明，采用80nm大粒径、高浓度的SiO2磨料，既可以保证抛光速率，又能得到良好的表面状；当pH值在10～12时，可加速蓝宝石在碱性条件下的化学反应速率，从而提高抛光速率；在30℃时，能较好地平衡化学作用与机械作用，获得平滑表面；加入适量添加剂，可增大反应产物的体积，易于提高机械作用的效果，以获得较高的去除速率。     

蓝宝石衬底的化学机械抛光工艺研究

由于蓝宝石衬底片的精密加工工艺复杂,最优工艺参数尚未明确,是目前国内重点研究的难题.采用X62 81521型抛光机对蓝宝石衬底片的精密加工技术一化学机械抛光工艺进行了研究.通过对蓝宝石抛光工艺性能参数的系统分析,采用了粒径为40 nm、低分散度的碱性SiO2,溶胶抛光液;通过大量实验总结,提出了优化方案,在pH值11.7、温度40 °c、压力在0.12 Mpa至0.15 Mpa时,可以获得的去除速率为12.1μm/h,表面粗糙度为0.58 nm,有效地提高了蓝宝石表面的性能及加工效率.     

Si衬底GaN基材料及器件的研究

GaN具有禁带宽、热导率高等特点,广泛应用于光电子和微电子器件领域.Si衬底GaN基材料及器件的研制将进一步促进GaN基器件与传统器件工艺的集成,因而具有很高的研究价值.介绍了Si衬底GaN基材料生长及特性方面的研究现状和GaN基器件的进展情况.     

预处理蓝宝石衬底上生长高质量 GaN 显示薄膜

采用化学方法腐蚀部分 c-面蓝宝石衬底,在腐蚀区域形成一定的图案,利用 LP-MOCVD 在此经过表面处理的蓝宝石衬底上外延生长 GaN 薄膜.采用高分辨率双晶X射线衍射(DCXRD)、光致发光光谱(PL)、透射光谱分析GaN薄膜的晶体质量和光学质量.分析结果表明,CaN 薄膜透射谱反映出的 CaN 质量与 X射线双晶衍射测量的结果一致,即透射率越大,半高宽越小,结晶质量越好;对蓝宝石衬底进行前处理可以大大改善GaN薄膜的晶体质量和光学质量,其(0002)面及(1012)面XRD半高宽(FWHM)分别降低到 208.80arcsec 及 320.76arcsec,而且其光致发光谱中的黄光带几乎可以忽略.     

ULSI硅衬底的化学机械抛光技术

介绍了特大规模集成电路(ULSI)硅衬底的化学机械抛光工艺.对抛光机理、影响抛光速率和抛光质量的因素、抛光液中的成份特别是精抛液中的有机碱和活性剂的选择作了讨论分析,另外对抛光中出现的一些问题及解决方法进行了分析研究.     

HVPE法制备GaN过程中GaAs衬底的氮化

在自制的立式氢化物气相外延(HVPE)系统炉中,一定温度下通入一定流量的NH3使GaAs(111)衬底氮化一层GaN薄膜,以防止高温外延生长GaN时GaAs分解,进而提高了之后GaN外延生长的晶体质量。实验主要通过XRD检测氮化层的质量,研究了氮化温度和时间对氮化层的影响。实验发现,氮化温度过高会使GaAs表面分解,氮化层为多晶。氮化时间过短,氮化层致密性低,不能起到保护衬底的作用;时间过长则氮化层质量降低,GaN(002)半高宽(FWHM)较大。分析结果表明,在500℃氮化2min的工艺条件下,获得的氮化层质量相比其他条件较好,致密性高。     

ULSI硅衬底的化学机械抛光

在分析UL SI中硅衬底CMP的动力学过程基础上,提出了在机械研磨去除产物过程中,适当增强化学作用可显著改善产物的质量传输过程,从而提高抛光效率.在对不同粒径分散度的硅溶胶抛光液进行比较后提出了参与机械研磨的有效粒子数才是机械研磨过程的重要因素,而不是单纯受粒径大小的影响.分析和讨论了CMP工艺中的几个影响因素,如粒径大小与分散度、p H值、温度、流量和浓度等.采用含表面活性剂和螯合剂的清洗液进行抛光后清洗,表面颗粒数优于国际SEMI标准,抛光雾得到了有效控制     

Si衬底和Si-SiO2-Si柔性衬底上的GaN生长

使用MBE方法在Si(111)衬底和Si-SiO2-Si柔性衬底上生长了GaN外延层,并对在两种衬底上生长的样品进行了对比分析.在柔性衬底上获得了无裂纹的外延层,其表面粗糙度为0.6nm.研究了GaN外延层中的应力及其光学性质,光致发光测试结果表明柔性衬底上生长的外延层中应力和杂质浓度明显低于直接生长在Si衬底上的样品的值.研究结果显示了所用柔性衬底有助于改善GaN外延膜的质量.     

Si衬底和Si-SiO_2-Si柔性衬底上的GaN生长

使用MBE方法在Si(111)衬底和Si SiO2 Si柔性衬底上生长了GaN外延层 ,并对在两种衬底上生长的样品进行了对比分析 .在柔性衬底上获得了无裂纹的外延层 ,其表面粗糙度为 0 6nm .研究了GaN外延层中的应力及其光学性质 ,光致发光测试结果表明柔性衬底上生长的外延层中应力和杂质浓度明显低于直接生长在Si衬底上的样品的值 .研究结果显示了所用柔性衬底有助于改善GaN外延膜的质量     

ULSI硅衬底的化学机械抛光

在分析ULSI中硅衬底CMP的动力学过程基础上,提出了在机械研磨去除产物过程中,适当增强化学作用可显著改善产物的质量传输过程,从而提高抛光效率.在对不同粒径分散度的硅溶胶抛光液进行比较后提出了参与机械研磨的有效粒子数才是机械研磨过程的重要因素,而不是单纯受粒径大小的影响.分析和讨论了CMP工艺中的几个影响因素,如粒径大小与分散度、pH值、温度、流量和浓度等.采用含表面活性剂和螯合剂的清洗液进行抛光后清洗,表面颗粒数优于国际SEMI标准,抛光雾得到了有效控制.     

Chemical mechanical polishing of freestanding GaN substrates

Chemical mechanical polishing (CMP) has been used to produce smooth and scratch-free surfaces for GaN. In the aqueous solution of KOH, GaN is subjected to etching. At the same time, all surface irregularities, including etch pyramids, roughness after mechanical polishing and so on will be removed by a polishing pad. The experiments had been performed under the condition of different abrasive particle sizes of the polishing pad. Also the polishing results for different polishing times are analyzed, and chemical mechanical polishing resulted in an average root mean square (RMS) surface roughness of 0.565 nm, as measured by atomic force microscopy.     

Final polishing of Ga-polar GaN substrates using reactive ion etching

Reactive ion etching of {0001} oriented plate-like GaN single crystals has been investigated using SiCl₄:Ar:SF₆ chemistry. The reactive ion etching process is highly chemical. Large anisotropy of the etching rate and of the morphology has been established on (000 ) N-polar and (0001) Ga-polar sides of the GaN crystals, with remarkably higher rate on the N-polar side. Atomic force microscopy measurements have shown smooth surface and good polishing effect obtained on Ga-polar side, while N-polar surface exhibits an increased roughness of a factor of 10 after RIE.     

Chemical mechanical polishing of polycarbonate and poly methyl methacrylate substrates

In recent years, polymeric materials such as polycarbonate (PC) and poly methyl methacrylate (PMMA) are replacing silicon as major substrates in microfluidic system fabrication due to the outstanding features like low cost and good chemical resistance. In this study, chemical mechanical polishing (CMP) of PC and PMMA substrates was investigated. First, four types of slurry were tested. Then, the slurry producing relatively high material removal rate (MRR) and low surface roughness was chosen, and experiments were designed and carried out to investigate the effects of key process parameters. The experimental results show impacts of key CMP process parameters on MRR and surface finish of PC and PMMA substrates. An increase in head load or table speed would cause an increase in surface roughness heights and MRR. The surface quality of the polymers after CMP appeared to be acceptable for most of microelectromechanical system applications as the process conditions were restrained within the process window.     

Chemical polishing of CdZnTe substrates fabricated from crystals grown by the vertical-gradient freezing method

Chemical polishing is a process of crucial importance in the manufacture of epiready substrates for molecular beam epitaxy (MBE) of high-quality HgCdTe layers. With the aim of fabrication of (211) CdZnTe substrates, we focused on the fundamental research of polishing processes with respect to reducing subsurface damage. Wafers of the orientation (211) were prepared from the as-grown crystals by a process flow including oriented slicing, several steps of mechanical polishing, and finally chemical polishing. In the prechemical polishing process, several free and bound abrasives were applied to reach the surface roughness close to 1 nm. The surface polishing treatment included testing of the surface quality after each polishing step. We used an interferometer profiler, which yields detailed surface maps. Within chemical polishing processing, we have looked for an optimum composition of etchant based on the bromine-methanol/ethylene glycol solution and adequate polishing pad. We studied the substrate surface quality dependence on the rotation speed of the plate, sample loading weights, and duration of polishing. Correlation between the final surface roughness and layer thickness removed was established. The chemical polishing with a very low concentration of Br-methanol/ethylene glycol solution was found to yield very good CdZnTe surfaces with a perfect flatness.     

抛光对GOI(Germanium-on-Insulator)衬底的影响

We prepared germanium-on-insulator(GOI) substrates by using Smart-CutTM and wafer bonding technology. The fabricated GOI is appropriate for polishing due to a strong bonding strength(2.4 MPa) and a sufficient bonding quality.We investigated mechanical polishing and chemical-mechanical polishing(CMP) systematically, and an appropriate polishing method—mechanical polishing combined with CMP-is obtained.As shown by AFM measurement,the RMS of GOI after polishing decreased to 0.543 nm.And the Ge peak profile of the XRD curve became symmetric,and the FWHM is about 121.7 arcsec,demonstrating a good crystal quality.     

大直径硅晶片化学机械抛光及其终点检测技术的研究与应用

化学机械抛光是硅片全局平坦化的核心技术,然而在实用阶段上,这项技术还受限于一些制造系统整合上的问题,其中有效的终点检测系统是影响抛光成效的重要关键.若未能有效地监测抛光运作,便无法避免硅片产生抛光过度或不足的缺陷.本文在介绍CMP机制与应用的基础上,系统分析了CMP终点检测技术的研究现状及存在的问题.     

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.     

SiLK dielectric planarization by chemical mechanical polishing

As the feature size of integrated circuits is driven to smaller dimensions the importance of the inter- and intralayer isolator capacitance in future metallization schemes becomes more pronounced. Organic polymers with low dielectric constants are one class of material choice for the replacement of SiO₂. However, their successful integration into functional circuits requires new fabrication procedures. The embedded dielectric scheme offers an evolutionary path for their successful integration into a subtractive etched, aluminum-based integrated circuit. This scheme can effectively lower the total capacitance while minimally changing the rest of the metallization fabrication process. However, the non-conformal deposition of spin-on polymers requires an effective planarization process. Therefore, this paper focuses on the planarization capability of a chemical mechanical polishing process (CMP) using SiLK resin as the interlayer dielectric material. The experimental results demonstrate the high planarization capability of the CMP process using a commercially available slurry. The post-CMP degree of planarization is greater than 95% for all feature dimensions and this planarity can be achieved rapidly. SiLK dielectric coatings are therefore considered as a promising candidate to replace SiO₂ in existing Al/W-based technologies.     

Effect of ammonium molybdate concentration on chemical mechanical polishing of glass substrate

The effect of the ammonium molybdate concentration on the material removal rate(MRR) and surface quality in the preliminary chemical mechanical polishing(CMP) of a rough glass substrate was investigated using a silica-based slurry.Experimental results reveal that the ammonium molybdate concentration has a strong influence on the CMP behaviors of glass substrates.When the ammonium molybdate was added to the baseline slurry,polishing rates increased,and then decreased with a transition at 2 wt.%,and the ro...     

超大规模集成电路制造中硅片化学机械抛光技术分析

目前半导体制造技术已经跨入0.13μm 和300mm时代,化学机械抛光(CMP)技术在ULSI制造中得到了快速发展,已经成为特征尺寸0.35μm以下IC制造不可缺少的技术。CMP是唯一能够实现硅片局部和全局平坦化的方法,但CMP的材料去除机理至今还没有完全理解、CMP系统过程变量和技术等方面的许多问题还没有完全弄清楚。本文着重介绍了化学机械抛光材料去除机理以及影响硅片表面材料去除率和抛光质量的因素。