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.     

低磨料浓度的碱性铜抛光液平坦化性能的研究

A novel alkaline copper slurry that possesses a relatively high planarization performance is investigated under a low abrasive concentration.Based on the action mechanism of CMP,the feasibility of using one type of slurry in copper bulk elimination process and residual copper elimination process,with different process parameters,was analyzed.In addition,we investigated the regular change of abrasive concentration effect on copper and tantalum removal rate and within wafer non-uniformity(WIWNU) in CMP process.When the abrasive concentration is 3 wt%,in bulk elimination process,the copper removal rate achieves 6125 °/min,while WIWNU is 3.5%,simultaneously.In residual copper elimination process,the copper removal rate is approximately 2700°/min,while WIWNU is 2.8%.Nevertheless,the tantalum removal rate is 0 °/min,which indicates that barrier layer isn’t eliminated in residual copper elimination process.The planarization experimental results show that an excellent planarization performance is obtained with a relatively high copper removal rate in bulk elimination process.Meanwhile,after residual copper elimination process,the dishing value increased inconspicuously,in a controllable range,and the wafer surface roughness is only 0.326 nm(sq < 1 nm) after polishing.By comparison,the planarization performance and surface quality of alkaline slurry show almost no major differences with two kinds of commercial acid slurries after polishing.All experimental results are conducive to research and improvement of alkaline slurry in the future.     

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     

The stability of a novel weakly alkaline slurry of copper interconnection CMP for GLSI

Chemical mechanical polishing (CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI,meanwhile polishing slurry is a critical factor for realizing the high polishing performance such as high planarization efficiency,low surface roughness.The effect of slurry components such as abrasive (colloidal silica),complexing agent (glycine),inhibitor (BTA) and oxidizing agent (H2O2) on the stability of the novel weakly alkaline slurry of copper interconnection CMP for GLSI was investigated in this paper.First,the synergistic and competitive relationship of them in a peroxide-based weakly alkaline slurry during the copper CMP process was studied and the stability mechanism was put forward.Then 1 wt％ colloidal silica,2.5 wt％ glycine,200 ppm BTA,20 mL/L H2O2 had been selected as the appropriate concentration to prepare copper slurry,and using such slurry the copper blanket wafer was polished.From the variations of copper removal rate,root-mean square roughness (Sq) value with the setting time,it indicates that the working-life of the novel weakly alkaline slurry can reach more than 7 days,which satisfies the requirement of microelectronics further development.     

光学石英基片CMP表面粗糙度的研究

In order to achieve a high-quality quartz glass substrate and to improve the performance of Ti O2 antireflection coating,chemical mechanical polishing(CMP) method was used.During CMP process,some process parameters including pressure,polishing head speed,platen speed,slurry flow rate,polishing time,and slurry temperature were optimized to obtain lower quartz surface roughness.According to the experiment results,when pressure was 0.75 psi,polishing head speed was 65 rpm,platen speed was 60 rpm,slurry flow rate 150 m L/min,slurry temperature 20°C,and polishing time was 60 s,the material removal rate(MRR) was 56.8 nm/min and the surface roughness(Ra) was 1.93 °(the scanned area was 1010 m2/.These results were suitable for the industrial production requirements.     

Material removal rate of 6H-SiC crystal substrate CMP using an alumina（Al2O3） abrasive

正The influences of the polishing slurry composition,such as the pH value,the abrasive size and its concentration,the dispersant and the oxidants,the rotational velocity of the polishing platen and the carrier and the polishing pressure,on the material removal rate of SiC crystal substrate(0001) Si and a(0001) C surface have been studied based on the alumina abrasive in chemical mechanical polishing(CMP).The results proposed by our research here will provide a reference for developing the slurry,optimizing the process parameters,and investigating the material removal mechanism in the CMP of SiC crystal substrate.     

A new weakly alkaline slurry for copper planarization at a reduced down pressure

This study reports a new weakly alkaline slurry for copper chemical mechanical planarization （CMP）, it can achieve a high planarization efficiency at a reduced down pressure of 1.0 psi. The slurry is studied through the polish rate, planarization, copper surface roughness and stability. The copper polishing experiment result shows that the polish rate can reach 10032 A/rain. From the multi-layers copper CMP test, a good result is obtained, that is a big step height （10870 A） that can be eliminated in just 35 s, and the copper root mean square surface roughness （sq） is very low （〈 1 rim）. Apart from this, compared with the alkaline slurry researched before, it has a good progress on stability of copper polishing rate, stable for 12 h at least. All the results presented here are relevant for further developments in the area of copper CMP.     

TiO2 薄膜CMP表面粗糙度的研究

Abstract： Surface roughness by peaks and depressions on the surface of titanium dioxide （TiO2） thin film, which was widely used for an antireflection coating of optical systems, caused the extinction coefficient increase and affected the properties of optical system. Chemical mechanical polishing （CMP） is a very important method for surface smoothing. In this polishing experiment, we used self-formulated weakly alkaline slurry. Other process parameters were working pressure, slurry flow rate, head speed, and platen speed. In order to get the best surface roughness （1.16 A, the scanned area was 10 × 10 μm2） and a higher polishing rate （60.8 nm/min）, the optimal parameters were： pressure, 1 psi; slurry flow rate, 250 mL/min; polishing head speed, 80 rpm; platen speed, 87 rpm.     

Investigation of aluminum gate CMP in a novel alkaline solution

Beyond 45 nm, due to the superior CMP performance requirements with the metal gate of aluminum in the advanced CMOS process, a novel alkaline slurry for an aluminum gate CMP with poly-amine alkali slurry is investigated. The aluminum gate CMP under alkaline conditions has two steps:stock polishing and fine polishing. A controllable removal rate, the uniformity of aluminum gate and low corrosion are the key challenges for the alkaline polishing slurry of the aluminum gate CMP. This work utilizes the complexation-soluble function of FA/O Ⅱ and the preference adsorption mechanism of FA/O Ⅰ nonionic surfactant to improve the uniformity of the surface chemistry function with the electrochemical corrosion research, such as OCP-TIME curves, Tafel curves and AC impedance. The result is that the stock polishing slurry (with SiO₂ abrasive) contains 1 wt.% H₂O₂ ,0.5 wt.% FA/O Ⅱ and 1.0 wt.% FA/O Ⅰ nonionic surfactant. For a fine polishing process, 1.5 wt.% H₂O₂ , 0.4 wt.% FA/O Ⅱ and 2.0 wt.% FA/O Ⅰ nonionic surfactant are added. The polishing experiments show that the removal rates are 3000±50 Å/min and 1600±60 Å/min, respectively. The surface roughnesses are 2.05±0.128 nm and 1.59±0.081 nm, respectively. A combination of the functions of FA/O Ⅱ and FA/O Ⅰ nonionic surfactant obtains a controllable removal rate and a better surface roughness in alkaline solution.     

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.     

一种含有盐酸胍的新型TSV抛光液

本文中,对一种新型的含有盐酸胍的TSV抛光液在CMP(化学机械平坦化)中的性能进行了研究,该TSV抛光液是一种碱性抛光液,并且不含任何抑制剂。在抛光过程中,盐酸胍作为一种有效的表面复合单元,相对于铜和介质的去除速率,钛的去除速率是可以通过调节选择性来控制的。在TSV生产过程中对于表面蝶形坑的修正及得到好的表面平整度是有利的。本文主要研究了抛光液成分的作用机理以及盐酸胍在TSV抛光液中的巧妙应用。     

新型碱性抛光液对300mm TaN镀膜片CMP效果评估

TaN由于其良好的性能广泛用于布线铜与介质之间的阻挡层和黏附层.在对直径为300 mm的TaN镀膜片进行化学机械抛光(CMP)后,对比并分析了两种碱性抛光液对TaN去除速率、片内非均匀性、去除速率选择性和表面粗糙度的影响.结果表明,经过自主研发且不合氧化剂的碱性阻挡层抛光液抛光后,TaN的去除速率为40.1 nm/min,片内非均匀性为3.04％,介质、TaN与Cu的去除速率之比为1.69∶1.26∶1,中心、中间以及边缘的表面粗糙度分别为0.371,0.358和0.366 nm.与商用抛光液抛光结果相比,虽然采用自主研发的抛光液抛光的去除速率低,但片内非均匀性以及选择性均满足商用要求,且抛光后TaN表面粗糙度小,易清洗,无颗粒沾污.综合实验结果表明,自主研发的高性能碱性抛光液对TaN镀膜片具有良好的抛光效果,适合工业生产.     

ULSI铝布线化学机械抛光研究

在分析铝的物理化学特性的基础上,对甚大规模集成电路(ULSI)铝布线化学机械抛光(CMP)机理进行研究,确定采用碱性抛光液。阐述了所选pH值调节剂的特点,探讨了其在化学机械抛光过程中的作用机理,并分析了所选表面活性剂所发挥的提高高低选择比的作用。最后,对所选pH值调节剂和表面活性剂对铝化学机械抛光的影响进行了实验研究。结果表明:pH值在11.0时,去除速率最快,约为390nm/min;表面活性剂的加入对去除速率影响不大,但可以明显改善表面状态,表面粗糙度降至nm级。     

配置一种不加BTA和氧化剂的弱碱性阻挡层抛光液的机理分析

在阻挡层化学机械抛光中,实现可控的铜,钽,介质去除速率选择比是一项挑战。双氧水作为氧化剂加上BTA作为抑制剂的作用被认为是一种有效的方法。但是,由于双氧水易于分解使得含有双氧水的抛光液使用寿命短。另外,BTA对抛光后清洗带来挑战：在片子表面残留有毒的有机物和颗粒。最近,我们一直致力于研究一种不加氧化剂和BTA的阻挡层抛光液。在这些工作的基础上,本文的目的是通过实验研究抛光液中不同的组分（包括硅溶胶,FA/O螯合剂,溶液PH,硝酸）胍）对铜,钽,介质去除速率的影响来讨论配置这种新型的不加BTA和氧化剂的阻挡层抛光液的机理。相关可能的抛光机也会在本论文中提出。     

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.     

硅通孔抛光液的研究进展

硅通孔(TSV)技术是一种先进的封装技术,化学机械抛光(CMP)是集成电路TSV制作过程中的重要步骤之一,是可兼顾材料表面局部和全局平坦化的技术。抛光液是影响抛光表面质量和加工效率的关键因素,是CMP工艺中消耗品成本最大的部分。TSV抛光液主要包括铜膜抛光液和阻挡层抛光液,依据抛光速率和抛光质量(表面粗糙度、碟形坑修正等)的要求对其进行了分类讨论,概述了近年来TSV抛光液的研究进展,对其今后的研究重点和发展趋势进行了分析和预测,认为TSV抛光液应朝着抛光速率和抛光质量的优化、低成本、环境友好的方向发展。