Use of Malonic Acid in Chemical-Mechanical Polishing ( CMP ) of Tungsten

1997 ◽  
Vol 477 ◽  
Author(s):  
L. Zhang ◽  
S. Raghavan
Keyword(s):  
Zeta Potential ◽  
Malonic Acid ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Small Scale ◽  
Ph Values ◽  
Particulate Contamination ◽  
Principal Objective ◽  
Alumina Particles ◽  
Negative Zeta Potential

ABSTRACTThe use of malonic acid as an additive in alumina slurries used for the chemical mechanical polishing ( CMP ) of tungsten has been explored for the reduction of particulate contamination. The principal objective of this work was to delineate conditions under which alumina contamination on polished surfaces could be reduced.The interaction between malonic acid and alumina particles has been investigated through electrokinetic and adsorption measurements. At suitable malonic acid concentrations and pH values, tungsten and alumina surfaces develop a negative zeta potential resulting in conditions conducive to reduced particulate contamination. Small scale polishing experiments have been carried out to relate electrokinetic results to the level of particulate contamination after polishing.

Slurry Residue Removal in Post Chemical Mechanical Polishing

1999 ◽  
Author(s):  
Ahmed A. Busnaina ◽  
Naim Moumen
Keyword(s):  
Chemical Mechanical Polishing ◽  
Silicon Wafers ◽  
Mechanical Polishing ◽  
Operating Conditions ◽  
Cleaning Process ◽  
Megasonic Cleaning ◽  
Residue Removal ◽  
Particulate Contamination

Abstract The megasonic cleaning process proved to be an essential process in cleaning silicon wafers after processes such as pre-oxidation, pre-CVD, pre-EPI, post-ASH and lately post-CMP. Current post-CMP cleans are contact cleaning techniques. These contact techniques have a low throughput and may cause wafer scratching. In addition, in contact cleaning, brush shedding which occurs under many operating conditions causes additional particulate contamination. There is a need for an effective post-CMP cleaning process. Megasonic cleaning provides the best alternative or compliment to brush clean.

Studies on CO[sub 2]-Based Slurries and Fluorinated Silica and Alumina Particles for Chemical Mechanical Polishing of Copper Films

2006 ◽  
Vol 153 (12) ◽  
pp. G1064 ◽  
Author(s):  
Pamela M. Visintin ◽  
Sean K. Eichenlaub ◽  
Lauren E. Portnow ◽  
Ruben G. Carbonell ◽  
Stephen P. Beaudoin ◽  
...  
Keyword(s):  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Copper Films ◽  
Alumina Particles

Chemical Mechanical Polishing Slurry for Tungsten in ULSI With Large Particle Size Colloidal Silica Nano-Abrasive

2005 ◽  
Author(s):  
Kailiang Zhang ◽  
Zhitang Song ◽  
Songlin Feng
Keyword(s):  
Surface Roughness ◽  
Particle Size ◽  
Zeta Potential ◽  
Chemical Mechanical Polishing ◽  
Large Particle ◽  
Colloidal Silica ◽  
Removal Rate ◽  
Silica Sol ◽  
Mechanical Polishing ◽  
Large Particle Size

Silica sol nano-abrasives with large particle are prepared and characterized by TEM, PCS and Zeta potential in this paper. Results show that the silica sol nano-abrasives about 100nm are of higher stability (Zeta potential: −65mV) and narrow distribution of particle size. And then alkali CMP slurries for tungsten containing self-made silica sol nano-abrasives are prepared and applied. CMP results show that the removal rate has been improved to 367nm/min and the RMS of surface roughness has been reduced from 4.4nm to 0.80nm. In sum, one kind of alkali slurry containing 100nm silica sol for tungsten CMP is studied.

Effects of KIO4 concentration and pH values of the solution relevant for chemical mechanical polishing of ruthenium

2016 ◽  
Vol 151 ◽  
pp. 30-37 ◽  
Author(s):  
Jie Cheng ◽  
Tongqing Wang ◽  
Jie Wang ◽  
Yuhong Liu ◽  
Xinchun Lu
Keyword(s):  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Ph Values

A Particle-Augmented Mixed Lubrication Modeling Approach to Predicting Chemical Mechanical Polishing

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Elon J. Terrell ◽  
C. Fred Higgs
Keyword(s):  
Integrated Circuits ◽  
Chemical Mechanical Polishing ◽  
Material Removal ◽  
Removal Rate ◽  
Abrasive Particle ◽  
Mixed Lubrication ◽  
Mechanical Polishing ◽  
Small Scale ◽  
Modeling Approach ◽  
Fitting Parameters

Chemical mechanical polishing (CMP) is a manufacturing process that is commonly used to planarize integrated circuits and other small-scale devices during fabrication. Although a number of models have been formulated, which focus on specific aspects of the CMP process, these models typically do not integrate all of the predominant mechanical aspects of CMP into a single framework. Additionally, the use of empirical fitting parameters decreases the generality of existing predictive CMP models. Therefore, the focus of this study is to develop an integrated computational modeling approach that incorporates the key physics behind CMP without using empirical fitting parameters. CMP consists of the interplay of four key tribological phenomena—fluid mechanics, particle dynamics, contact mechanics, and resulting wear. When these physical phenomena are all actively engaged in a sliding contact, the authors call this particle-augmented mixed lubrication (PAML). By considering all of the PAML phenomena in modeling particle-induced wear (or material removal), this model was able to predict wear-in silico from a measured surface topography during CMP. The predicted material removal rate (MRR) was compared with experimental measurements of copper CMP. A series of parametric studies were also conducted in order to predict the effects of varying slurry properties such as solid fraction and abrasive particle size. The results from the model are promising and suggest that a tribological framework is in place for developing a generalized first-principle PAML modeling approach for predicting CMP.

The Effects of Particle Adhesion in Chemical Mechanical Polishing

2003 ◽  
Vol 767 ◽  
Author(s):  
Zhenyu Lu ◽  
S.V. Babu ◽  
Egon Matijević
Keyword(s):  
Chemical Mechanical Polishing ◽  
Packed Column ◽  
Mechanical Polishing ◽  
Surface Films ◽  
Strong Correlations ◽  
Abrasive Particles ◽  
Spherical Silica ◽  
Alumina Particles ◽  
Slurry Flow Rate ◽  
Film Interface

AbstractThe properties of abrasive particles, and their interactions with surface films to be polished, play a key role in chemical mechanical polishing (CMP). This study applies the packed column technique for the investigation of the adhesion phenomena at the particle/film interface as a function of different slurry chemistries relevant to polishing processes. Well-defined dispersions, including uniform spherical silica and silica cores coated with nanosized ceria, as well as calcined alumina were used to represent slurry abrasives, and copper or glass beads to simulate wafers or discs. It was shown that the pH and slurry flow rate had significant effects on particle attachment and removal. The results of deposition of silica particles on copper beads in the presence of various concentrations of H2O2 and of detachment from copper beads of alumina particles, loaded at different pH values, had strong correlations to the polish rates of the metal.

scholarly journals Agglomeration of Silicon Dioxide Nanoscale Colloids in Chemical Mechanical Polishing Wastewater: Influence of pH and Coagulant Concentration

2019 ◽  
Vol 29 (3) ◽  
pp. 252-271
Author(s):  
Mohamad Zuki Noor Aina ◽  
Jing Yao Sin ◽  
Amane Jada ◽  
Arezoo Fereidonian Dashti ◽  
Mohd Omar Fatehah
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Silicon Dioxide ◽  
Chemical Mechanical Polishing ◽  
Average Particle Size ◽  
Mechanical Polishing ◽  
Second Phase ◽  
Average Particle ◽  
Sulfate Heptahydrate ◽  
Nanoscale Clusters

Abstract Chemical mechanical polishing (CMP) wastewater generated from semiconductor manufacturing industries is known to contain residual organic and inorganic contaminants, i.e. photoresists, acids, including silicon dioxide (SiO2), nanoparticles (NPs) and others. Nanoscale colloids in CMP wastewater have strong inclination to remain in the suspension, leading to high turbidity and chemical oxygen demand (COD). Although various types of pre-treatment have been implemented, these nanoparticles remain diffused in small clusters that pass through the treatment system. Therefore, it is crucial to select suitable pH and coagulant type in the coagulation treatment process. In this research zeta potential and dynamic light scattering measurements are applied as preliminary step aimed at determining optimum pH and coagulant dosage range based on the observation of inter particle-particle behavior in a CMP suspension. The first phase of the conducted study is to analyze nanoscale colloids in the CMP suspension in terms of zeta potential and z-average particle size as a function of pH within a range of 2 to 12. Two types of coagulants were investigated - polyaluminum chloride (PACl) and ferrous sulfate heptahydrate (FeSO4·7H2O). Similar pH analysis was conducted for the coagulants with the same pH range separately. The second phase of the study involved evaluating the interaction between nanoscale colloids and coagulants in the suspension. The dynamics of zeta potential and corresponding particle size were observed as a function of coagulant concentration. Results indicated that CMP wastewater is negatively charged, with average zeta potential of -59.8 mV and 149 d.nm at pH value of 8.7. The interaction between CMP wastewater and PACl showed that positively charged PACl rapidly adsorbed colloids in the wastewater, reducing the negative surface charge of nanoscale clusters. The interaction between CMP wastewater and FeSO4·7H2O showed that larger dosage is required to aggregate nanoscale clusters, due to its low positive value to counter negative charges of CMP wastewater.

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