大分子螯合剂在低压力低磨料条件下铜膜的化学机械抛光中的应用

The mechanism of the FA/O chelating agent in the process of chemical mechanical polishing （CMP） is introduced. CMP is carried on a φ300 mm copper film. The higher polishing rate and lower surface roughness are acquired due to the action of an FA/O chelating agent with an extremely strong chelating ability under the condition of low pressure and low abrasive concentration during the CMP process. According to the results of several kinds of additive interaction curves when the pressure is 13.78 kPa, flow rate is 150 mL/min, and the rotating speed is 55/60 rpm, it can be demonstrated that the FA/O chelating agent plays important role during the CMP process.     

不同压力下螯合剂浓度在碱性Cu CMP中的影响

We propose the action mechanism of Cu chemical mechanical planarization(CMP) in an alkaline solution.Meanwhile,the effect of abrasive mass fraction on the copper removal rate and within wafer non-uniformity(WIWNU) have been researched.In addition,we have also investigated the synergistic effect between the applied pressure and the FA/O chelating agent on the copper removal rate and WIWNU in the CMP process.Based on the experimental results,we chose several concentrations of the FA/O chelating agent,which added in the slurry can obtain a relatively high removal rate and a low WIWNU after polishing,to investigate the planarization performance of the copper slurry under different applied pressure conditions.The results demonstrate that the copper removal rate can reach 6125 °/min when the abrasive concentration is 3 wt.%.From the planarization experimental results,we can see that the residual step height is 562 ° after excessive copper of the wafer surface is eliminated.It denotes that a good polishing result is acquired when the FA/O chelating agent concentration and applied pressure are fixed at 3 vol% and 1 psi,respectively.All the results set forth here are very valuable for the research and development of alkaline slurry.     

Alkaline barrier slurry applied in TSV chemical mechanical planarization

We have proposed a TSV （through-silicon-via） alkaline barrier slurry without any inhibitors for barrier CMP （chemical mechanical planarization） and investigated its CMP performance. The characteristics of removal rate and selectivity of Ti/SiO2/Cu were investigated under the same process conditions. The results obtained from 6.2 mm copper, titanium and silica show that copper has a low removal rate during barrier CMP by using this slurry, and Ti and SiO2 have high removal rate selectivity to Cu. Thus it may be helpful to modify the dishing. The TSV wafer results reveal that the alkaline barrier slurry has an obvious effect on surface topography correction, and can be applied in TSV barrier CME     

盐酸胍在阻挡层化学机械抛光中对速率选择性及表面形貌的影响

We propose an alkaline barrier slurry containing guanidine hydrochloride（GH） and hydrogen peroxide.The slurry does not contain any corrosion inhibitors, such as benzotriazole（BTA）. 3-inch samples of tantalum copper and oxide were polished to observe the removal rate. The effect of GH on removal rate selectivity along withhydrogenperoxidewasinvestigatedbycomparingslurrycontainingGHandH2O2withslurrycontainingonly GH. Details about the tantalum polishing mechanism in an alkaline guanidine-based slurry and the electrochemical reactions are discussed. The results show that guanidine hydrochloride can increase the tantalum polishing rate and the selectivity of copper and barrier materials. The variation of the dishing and wire line resistance with the polishing time was measured. The dishing value after a 300 mm pattern wafer polishing suggests that the slurry has an effective performance in topography modification. The result obtained from the copper wire line resistance test reveals that the wire line in the trench has a low copper loss.     

Cu CMP工艺中新型低pH碱性抛光液稳定性的研究

Abstract： The stability of a novel low-pH alkaline slurry （marked as slurry A, pH = 8.5） for copper chemical mechanical planarization was investigated in this paper. First of all, the stability mechanism of the alkaline slurry was studied. Then many parameters have been tested for researching the stability of the slurry through comparing with a traditional alkaline slurry （marked as slurry B, pH = 9.5）, such as the pH value, particle size and zeta potential. Apart from this, the stability of the copper removal rate, dishing, erosion and surface roughness were also studied. All the results show that the stability of the novel low-pH alkaline slurry is better than the traditional alkaline slurry. The working-life of the novel low-pH alkaline slurry reaches 48 h.     

新型碱性精抛液对300mm铜膜全局平坦化的影响

The copper removal rate and uniformity of two types copper slurries were investigated, which was performed on the 300 mm chemical mechanical planarization （CMP） platform. The experiment results illustrate that the removal rate of the two slurries is nearly the same. Slurry A is mainly composed ofa FA/OI1 type chelating agent and the uniformity reaches to 88.32%. While the uniformity of slurry B is 96.68%, which is mainly composed of a FA/OV type chelating agent. This phenomenon demonstrates that under the same process conditions, the uniformity of different slurries is vastly different. The CMP performance was evaluated in terms of the dishing and erosion values. In this paper, the relationship between the uniformity and the planarization was deeply analyzed, which is mainly based on the endpoint detection mechanism. The experiment results reveal that the slurry with good uniformity has low dishing and erosion. The slurry with bad uniformity, by contract, increases Cu dishing significantly and causes copper loss in the recessed region. Therefore, the following conclusions are drawn： slurry B can improve the wafer leveling efficiently and minimize the resistance and current density along the line, which is helpful to improve the device yield and product reliability. This investigation provides a guide to improve the uniformity and achieve the global and local planarization. It is very significant to meet the requirements for 22 nm technology nodes and control the dishing and erosion efficiently.     

各组分体积分数对碱性抛光液存储时间的影响

主要研究了碱性抛光液各组分体积分数对其有效存储时间的影响。实验中每隔两个月测试了抛光液的pH值、平均粒径和Cu膜去除速率等参数随存储时间的变化值。研究表明:FA/O螯合剂体积分数是影响抛光液有效存储时间的主要因素,螯合剂体积分数越高抛光液的有效存储时间越短。在FA/O螯合剂体积分数较低时(8%),Cu布线碱性抛光液的有效存储时间在半年以上,基本能够符合产业化要求。SiO2磨料体积分数和非离子型表面活性剂体积分数是影响碱性抛光液有效存储时间的次要因素,对其有效存储时间影响不明显。     

催化反应对低磨料浓度化学机械平坦化的影响

通过低磨料浓度下催化反应对铜膜抛光速率的影响,证实了纳米SiO2胶体作为催化反应物可以极大地提高铜膜表面的化学反应速率。通过浸泡在不同磨料浓度抛光液中的铜电极表面腐蚀电位和腐蚀电流数值,进一步证实了催化反应能够加速凹处钝化膜的生成,并确定了在静态腐蚀条件下催化反应速率转换临界点所对应的纳米SiO2溶胶浓度为0.1vol%和1vol%。根据催化反应对铜晶圆各平坦化参数的影响,确定了低磨料CMP的最佳纳米SiO2溶胶浓度为0.3vol%,此时铜晶圆的抛光速率、台阶消除量、平坦化效率、碟形坑高度和腐蚀坑高度分别为535nm/min、299nm、56%、103nm和19nm。     

一种基于UML的网络安全体系建模分析方法

在现有法律法规和标准体系的指导下,提出了一种通用的网络安全体系框架,阐述了安全目标、安全边界、安全体系要素与安全服务和安全风险评估之间的关系.在网络安全体系框架的基础上,利用统一建模语言(Unified Modeling Language,UML)在建模表述上的强大性和通用性给出了安全目标、安全边界和安全体系要素的建模方法,以规范化安全体系的表示形式并消除沟通中的歧义性.利用建立的模型,安全管理员使用提出的网络安全建模分析方法,可以验证业务流程的目标满足性并得出可能的安全风险.最后通过一个典型网上银行网络的建模分析,验证了提出的安全体系框架和建模分析方法的有效性和合理性.相比于传统的方法,该方法建模分析要素更为全面,且推导得出的结果指导性更强.     

磨料对计算机硬盘NiP基板CMP质量的影响

磁盘表面质量直接影响了硬盘的磁存储密度,表面须达到优异的表面光滑度、没有表面缺陷.本文通过对镍磷基板的化学性质分析,讨论了其CMP机理,分析了浆料中的磨料在硬盘基板CMP中的重要性,指出浆料中的磨料不仅起到了机械研磨的作用,同时也充当了微型搅拌器的作用;通过实验分析了碱性浆料下磨料的浓度和粒径对镍磷基板CMP去除速率与表面粗糙度的影响;选用小粒径、低硬度的二氧化硅水溶胶磨料实现了较高的去除速率和较低的表面粗糙度.