scholarly journals Dynamic Pad Surface Metrology Monitoring by Swing-Arm Chromatic Confocal System

2020 ◽  
Vol 11 (1) ◽  
pp. 179
Author(s):  
Chao-Chang A. Chen ◽  
Jen-Chieh Li ◽  
Wei-Cheng Liao ◽  
Yong-Jie Ciou ◽  
Chun-Chen Chen
Keyword(s):  
Surface Topography ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Surface Profile ◽  
Performance Level ◽  
Wafer Surface ◽  
Surface Metrology ◽  
Effective Lifetime ◽  
Polishing Pad ◽  
Swing Arm

This study aims to develop a dynamic pad monitoring system (DPMS) for measuring the surface topography of polishing pad. Chemical mechanical planarization/polishing (CMP) is a vital process in semiconductor manufacturing. The process is applied to assure the substrate wafer or thin film on wafer that has reached the required planarization after deposition for lithographic processing of the desired structures of devices. Surface properties of polishing pad have a huge influence on the material removal rate (MRR) and quality of wafer surface by CMP process. A DPMS has been developed to analyze the performance level of polishing pad for CMP. A chromatic confocal sensor is attached on a designed fixture arm to acquire pad topography data. By swing-arm motion with continuous data acquisition, the surface topography information of pad can be gathered dynamically. Measuring data are analyzed with a designed FFT filter to remove mechanical vibration and disturbance. Then the pad surface profile and groove depth can be calculated, which the pad’s index PU (pad uniformity) and PELI (pad effective lifetime index) are developed to evaluate the pad’s performance level. Finally, 50 rounds of CMP experiments have been executed to investigate the correlations of MRR and surface roughness of as-CMP wafer with pad performance. Results of this study can be used to monitor the pad dressing process and CMP parameter evaluation for production of IC devices.

Effects of the Profile of Workpiece Surface on Material Removal Rate Distribution in Polishing Process

2016 ◽  
Vol 851 ◽  
pp. 149-154
Author(s):  
Zhen Gang Wu ◽  
Dong Shan He ◽  
Ping Zhou ◽  
Dong Ming Guo
Keyword(s):  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Profile ◽  
Prediction Method ◽  
Quantitative Prediction ◽  
Polishing Process ◽  
Workpiece Surface ◽  
Coefficient Distribution ◽  
Polishing Pad

Accurate prediction of the material removal rate (MRR) distribution is very important for the control of the polishing process. However, the widely used prediction method of MRR based on the Preston equation is still incapable of predicting the roll-off phenomenon in polishing process. One of the reasons is that many of the researchers’ neglected the effect of the surface profile of the workpiece on the MRR. In this paper, the evolutionary process of MRR distribution with the change of surface profile using two different polishing pad is studied, it is found that MRR varies gradually with the change of surface profile and tends to be uniform finally. Based on the analysis of contact pressure considering the actual surface profile of workpiece and modified Preston equation, the distribution of MRR is analyzed. It is found that the Preston coefficient distribution on workpiece surface is stable when the surface profile variation is small and shows obvious differences from the center to the edge of the workpiece. Through the comparison it is found that correlation between the regularities of Preston coefficient distribution and the type of polishing pad is significant. The research results in this paper will play an important guiding role in the quantitative prediction method research of polishing process.

Novel Measurement Technique on 3D Surface Topography of Polishing Pad

2008 ◽  
Vol 53-54 ◽  
pp. 265-272
Author(s):  
Dong Ming Guo ◽  
N. Qin ◽  
Ren Ke Kang ◽  
Zhu Ji Jin
Keyword(s):  
Surface Topography ◽  
Chemical Mechanical Planarization ◽  
Sampling Interval ◽  
3D Measurement ◽  
Sampling Area ◽  
Polishing Pad ◽  
3D Surface ◽  
3D Surface Topography ◽  
Planarization Process ◽  
Polishing Pads

Among the properties of polishing pad, the surface roughness plays a crucial role in CMP (Chemical Mechanical Planarization) process. However, there is no acknowledged standard for measuring and characterizing the roughness of pad surface in 3D measurement. In this paper Talysurf CLI 2000 working on the principle of dynamic confocal measurement was initially suggested to measure the 3D surface topography of polishing pads through theoretical and experimental analysis. In addition, based on the Nyquist folding frequency and the statistical theory, a selection technique for sampling interval and sampling area was proposed and verified through experiments. The results showed that Talysurf CLI 2000 is more suitable than NewView to measure the 3D surface topography of polishing pads. 2μm sampling interval, 0.5×0.5mm2 sampling area and 10μm interval, 1×1mm2 area are respectively recommended for IC1000/SubaIV and SubaIV polishing pad.

scholarly journals Role of Slurry Additives on Chemical Mechanical Planarization of Silicon Dioxide Film in Colloidal Silica Based Slurry

2021 ◽  
Author(s):  
Yue Li ◽  
chenwei wang ◽  
Jianwei Zhou ◽  
Yuanshen Cheng ◽  
晨 续 ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Silicon Dioxide ◽  
Colloidal Silica ◽  
Semiconductor Device ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Image Sensor ◽  
Wafer Surface ◽  
Silicon Dioxide Film ◽  
Dioxide Film

Abstract Chemical mechanical planarization (CMP) is a critical process for smoothing and polishing the surfaces of various material layers in semiconductor device fabrication. The applications of silicon dioxide films are shallow trench isolation, an inter-layer dielectric, and emerging technologies such as CMOS Image Sensor. In this study, the effect of various chemical additives on the removal rate of silicon dioxide film using colloidal silica abrasive during CMP was investigated. The polishing results show that the removal rate of silicon dioxide film first increased and then decreased with an increasing concentration of K+, pH, and abrasive size. The removal rate of silicon dioxide film increased linearly as the abrasive concentration increased. The influence mechanisms of various additives on the removal rate of silicon dioxide film were investigated by constructing simple models and scanning electron microscopy. Further, the stable performance of the slurry was achieved due to the COO- chains generated by poly(acrylamide) hydrolysis weaken the attraction between abrasives. High-quality wafer surfaces with low surface roughness were also thus achieved. The desirable and simple ingredient slurry investigated in this study can effectively enhance the planarization performance, for example, material removal rates and wafer surface roughness.

Study on Pad Conditioning Parameters in Silicon Wafer CMP Process

2007 ◽  
Vol 359-360 ◽  
pp. 309-313 ◽  
Author(s):  
Zhao Zhong Zhou ◽  
Ju Long Yuan ◽  
Bing Hai Lv ◽  
Jia Jin Zheng
Keyword(s):  
Surface Structure ◽  
Silicon Wafer ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Wafer Surface ◽  
Orthogonal Experiments ◽  
Pad Conditioning ◽  
High Level

Polishing pad plays a key role in determining polish rate and planarity of a chemical mechanical planarization (CMP). The properties of the pad would deteriorate during polishing because of pad surface grazing, which results in reduced removal rates and poorer planarity of wafer surface. Pad conditioning and its influence on pad surface structure and CMP process is introduced and discussed in this paper. The study shows that the surface structure can be regenerated by breaking up the glazed areas with conditioner, MRR(Material Removal Rate) can be maintained at high level with proper pad conditioning, and UN(Non-uniformity)can also improved. Orthogonal experiments design is employed in this study to determine the best conditioning parameters.

A Global Correction Process for Flat Optics With Patterned Polishing Pad

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Weisi Li ◽  
Ping Zhou ◽  
Zhichao Geng ◽  
Ying Yan ◽  
Dongming Guo
Keyword(s):  
Optical Glass ◽  
Removal Rate ◽  
Surface Profile ◽  
Prediction Method ◽  
Correction Method ◽  
Polishing Process ◽  
Polishing Pad ◽  
Edge Exclusion ◽  
Optics Fabrication ◽  
Surface Figure

To improve the efficiency of flat optics fabrication, a global correction method with the patterned polishing pad is developed in this paper. Through creating grooves on a polishing pad, the contact pressure distribution on the optics surface can be adjusted to change the material removal rate (MRR) distribution during polishing. Using the patterned pad, the selective removal ability of the polishing process is greatly enhanced. The predictability and stability of the MRR distribution are the preconditions to efficiently implement the proposed global correction method. Relying on the MRR distribution prediction method proposed and validated in this paper, the pad pattern can be designed based on the original surface figure of the workpieces. The designed groove pattern is created on the polishing pad using the custom-developed equipment. Then, the optical glass is polished on the designed pad with the optimized polishing time. A flat optical glass sample (Φ 100 mm) is polished with the global correction method to show its feasibility and advantage. The correction instance shows that the peak-to-valley (PV) value of the surface profile (with 3 mm edge exclusion) dropped from 1.17 µm to 0.2 µm in 14 min using a polyurethane pad with two ring grooves. Comparing with the conventional polishing process, which usually takes hours or days, the global correction method proposed in this paper can improve the efficiency of the optics manufacturing significantly.

Diamond Disc Pad Conditioning in Chemical Mechanical Planarization (CMP): A Mathematical Model to Predict Pad Surface Shape

2011 ◽  
Author(s):  
Z. C. Li ◽  
Emmanuel A. Baisie ◽  
X. H. Zhang
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Chemical Mechanical Planarization ◽  
Mathematic Model ◽  
Surface Shape ◽  
Surface Element ◽  
Wafer Surface ◽  
Polishing Pad ◽  
Pad Conditioning ◽  
Diamond Disc

Chemical mechanical planarization (CMP) is widely used to planarize semiconductor wafers and smooth the wafer surface. In CMP, a diamond disc conditioner is used to condition (or dress) a polishing pad to restore the pad performance. In this paper, a surface element method is proposed to develop a mathematic model to predict the pad surface shape resulted from diamond disc conditioning. The developed model is then validated by published experimental data. Results show that the model is effective to simulate the diamond disc conditioning process and predict the pad surface shape.

Optimizing the Within Wafer Non-Uniformity at the Chemical Mechanical Planarization step in Interposers and RDL fabrication process for 3D IC stacking

2019 ◽  
Vol 2019 (1) ◽  
pp. 000450-000453
Author(s):  
Amit Kumar ◽  
Jose Chacon ◽  
Peter Gelzinis ◽  
Ankineedu Velaga
Keyword(s):  
Relative Velocity ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Silicon Wafers ◽  
Fabrication Process ◽  
Wafer Surface ◽  
Slurry Flow ◽  
3D Ic ◽  
Standard Guideline ◽  
Slurry Composition

Abstract Chemical Mechanical Planarization (CMP) is an integral step in fabrication processes of through silicon via based Interposer and Redistribution layer for routing. The key motivation in the CMP process is to achieve planarization with minimum recess and dishing on the metal routing sites. In this work we established the metrics for Within-wafer non-uniformity (WIWNU) and optimized the CMP parameters. Currently, there is no standard guideline for reporting the WIWNU during CMP and thus a better understanding and practice is needed to enhance post CMP uniformity across the wafer. The work reported in this article were conducted on 200 mm silicon wafers with either Copper or Tungsten to optimize the uniformity of removal rate with respect to polishing parameters, such as slurry flow, slurry composition, down force, relative velocity of wafer surface with pad, etc. With optimized CMP parameters for blank wafer, the WIWNU in patterned wafer were evaluated and analyzed for additional optimization in non-uniformity.

Effect of Surface Profile on the Material Removal Rate Distribution in CMP Process

2014 ◽  
Vol 1017 ◽  
pp. 715-719
Author(s):  
Ping Zhou ◽  
Ji Qing Cai ◽  
Zhi Wei Li ◽  
Ren Ke Kang ◽  
Zhu Ji Jin
Keyword(s):  
Pressure Distribution ◽  
Material Removal Rate ◽  
Material Removal ◽  
Removal Rate ◽  
Surface Profile ◽  
Theoretical Research ◽  
Wafer Surface ◽  
Contact Pressure Distribution ◽  
Effect Of Surface

Material removal rate (MRR) distribution is a major concern in CMP process. In the published literatures, both experimental and theoretical research, MRR distribution is given without considering the surface profile of wafer. In this paper, the effect of surface profile on the MRR is analyzed based on the Preston equation and the contact pressure distribution calculated by the mixed lubrication model. It is found that the MRR distribution is dramatically affected by the profile of wafer surface, and whatever the polishing pad is conditioned in situ, the MRR distribution will be uniform at last. In addition, the wear of the pad surface induces a decrease of MRR.

Wafer Non-Uniformity Analysis during Chemical Mechanical Polishing Based on Finite Element Method

2010 ◽  
Vol 160-162 ◽  
pp. 1518-1523
Author(s):  
Shi Wen Du ◽  
Yong Tang Li ◽  
Jian Jun Song ◽  
Hui Ping Qi
Keyword(s):  
Finite Element ◽  
Chemical Mechanical Polishing ◽  
Mechanical Response ◽  
Layer Structure ◽  
Removal Rate ◽  
Mechanical Polishing ◽  
Wafer Surface ◽  
Finite Model ◽  
Polishing Pad ◽  
Low K

A contact-mechanics-based finite model for Cu/ low-k chemical mechanical polishing is presented. 2D axisymmetric quasi-static model for chemical mechanical polishing which includes four-layer structure: Si, low-k, Copper and polishing pad is established. The mechanical response at the interface between the silicon, low-k, copper, and pad is simulated under the loading of the chemical mechanical polishing. The effect of slurry is simplified as the friction force reacted onto both the copper and the polishing pad in the finite element model. Down pressure, status of slurry and the elastic modulus of polishing pad are treated as the parameter in the simulation. Using the model, the effects of applied down pressure, pad properties, status of slurry on the non-uniformity of the wafer surface can be readily evaluated. Simulation results show that the distribution of the Von Mises stresses across a wafer’s surface correlates with experimental removal rate profiles.

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