Potential-pH Diagrams of Interest to Chemical Mechanical Planarization of Copper Thin Films

2005 ◽  
Vol 867 ◽  
Author(s):  
Serdar Aksu
Keyword(s):  
Performance Metrics ◽  
Ethylenediaminetetraacetic Acid ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Copper Removal ◽  
Chemical Components ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Interlayer Dielectric ◽  
Cu Cmp

AbstractChemical mechanical planarization (CMP), which can globally planarize both silicon dioxide (the prevalent interlayer dielectric), and copper films, has become the key process in the damascene method used for producing integrated circuit (IC) devices with multilevel copper interconnects. Cu CMP is typically carried out with slurries containing oxidizing agents, complexing agents, and corrosion inhibitors as the principal chemical components. In such slurries, complexing agents enhance the solubility of copper and increase the dissolution rate of the abraded material in Cu CMP. They also assist achieving high copper removal rates during dynamic polishing conditions. The nature of the complexing agent used, the pH and the redox potential of the slurry system are among the main factors controlling the dissolution and passivation behaviors of copper during CMP. Consequently, these factors are intimately related to the key CMP performance metrics such as removal rate and planarity. In this paper, potentialpH diagrams of copper in aqueous systems containing a number of organic complexing agents including ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA), oxalic acid and malonic acid are presented. The predominance regions of copper complexes under different copper and ligand activities and their implications on copper removal during CMP are discussed.

Chemical-Mechanical Planarization of Copper: The Effect of Inhibitor and Complexing Agent

2003 ◽  
Vol 767 ◽  
Author(s):  
Ying Luo ◽  
Tianbao Du ◽  
Vimal Desai
Keyword(s):  
Hydrogen Peroxide ◽  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Electrochemical Process ◽  
Copper Removal ◽  
Alkaline Condition ◽  
Complexing Agent ◽  
Polarization Studies ◽  
Cu Cmp

AbstractThe present investigation was focused on understanding of the oxidation, dissolution and modification of Cu surface in slurries at various pH using hydrogen peroxide as oxidizer, glycine as complexing agent and 3-amino-triazol (ATA) as inhibitor during Cu-CMP. The electrochemical process involved in the oxidative dissolution of copper was investigated by potentiodynamic polarization studies. Surface modification of copper was investigated using Xray photoelectron spectroscopy to understand the interaction of Cu-H2O2-glycine-ATA during CMP. In the absence of glycine and ATA, the copper removal rate is found to be high in a slurry with 5% H2O2 at pH 2, then it decreases with increasing pH and reaches the minimum at pH 6, it continuously increases at alkaline condition. In the presence of 0.01M glycine, the removal rate of copper decreases in acidic slurries while increases significantly in alkaline slurries. With the further addition of ATA, the copper removal rate was reduced. However, better surface planarity was obtained. The present investigation enhanced understanding of the mechanism of Cu CMP in the presence of oxidizer, complexing agent and inhibitor for formulation of a highly effective CMP-slurry.

Modified Abrasives based on fumed SiO2 and Al2O3 for the Cu CMP Process

2004 ◽  
Vol 816 ◽  
Author(s):  
D. Zeidler ◽  
J.W. Bartha ◽  
W.L ortz ◽  
R. Brandes
Keyword(s):  
Surface Quality ◽  
High Selectivity ◽  
Removal Rate ◽  
New Method ◽  
Copper Removal ◽  
Complexing Agent ◽  
Abrasive Particles ◽  
Cu Cmp ◽  
Low Rate ◽  
Fumed Sio2

AbstractNew abrasive particles based on SiO2 and Al2O3 were produced with different coating and doping. Seven specifically designed particles were dispersed to prepare slurries for Cu CMP. Glycin was used as complexing agent and hydrogenperoxid as oxidizer. The experimentally obtained removal rate, selectivity, surface quality and planarisation ability, demonstrate a significant impact of the different abrasives tested. SiO2 particles covered with Al2O3 increased the removal rate for Cu. In comparison to this behavior, a low rate for TaN proved a high selectivity copper removal required by the Cu CMP process. A new method for the planarisation length monitoring (step polish response) shows also significant differences in planarisation length (PL) by the polish of copper with slurries composed of these new particles.

Effects of Alkaline Nano-SiO2 Abrasive on Planarization of 300mm Copper Patterned Wafer

2013 ◽  
Vol 634-638 ◽  
pp. 2949-2954
Author(s):  
Xin Liang Tang ◽  
Yu Ling Liu ◽  
Hong Yuan Zhang ◽  
Jie Bao
Keyword(s):  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Initial Step ◽  
Step Height ◽  
Copper Removal ◽  
Copper Wafers

Silica abrasive plays an important role in chemical mechanical planarization (CMP) of copper. In this paper, effect of different silica abrasive concentrations on copper removal rate and planarization performance of copper was investigated. The results show that the copper removal rate was increased as the concentration of silica abrasive increase. However, excessive abrasive will lead to a decreased copper removal rate. The initial step height values of the multilayer copper wafers were all about 2500Å, and after being polished for 30s, the remaining values of step height of slurry A, B, C and D were 717 Å, 906 Å, 1222 Å and 1493 Å. It indicates that alkaline copper slurries with different abrasive concentrations all had a good planarization performance on copper patterned wafer CMP. As the abrasive concentration increased, the planarization capability was enhanced.

Chemical Mechanical Polishing of Cu Pattern Wafer Based Alkaline Slurry in GLSI with R(NH2)n as Complexing Agent

2011 ◽  
Vol 236-238 ◽  
pp. 3020-3023 ◽  
Author(s):  
Yan Gang He ◽  
Xiao Wei Gan ◽  
Wei Hong ◽  
Yi Hu ◽  
Yu Ling Liu
Keyword(s):  
Reaction Mechanism ◽  
Chemical Mechanical Polishing ◽  
Mechanical Polishing ◽  
Complexing Agents ◽  
Complexing Agent ◽  
Mechanism Analysis ◽  
Slurry Stability ◽  
Cu Cmp ◽  
Better Than

Chemical mechanical polishing (CMP) of Cu pattern wafer based alkaline slurry in GLSI with R(NH2)n as complexing agent was investigated. In Cu CMP procedure, it is necessary to minimize the surface dishing and erosion while maintaining good planarity. This requirements are met through the complexing agents. Based on the reaction mechanism analysis of Cu in alkaline slurry with R(NH2)n as complexing agent in CMP, the performance of Cu dishing and erosion were discussed. The results showed that the slurry stability can be improved obviously by the addition of R(NH2)n as complexing agent, both Cu1 and Cu2 have good dishing and erosion performance. Furthermore, the dishing condition of Cu2 (180-230nm) is better than that of Cu1 (280-370nm), and the erosion condition of Cu2 (230-260nm) is also better than that of Cu1 (450-500nm).

Trace determination of gadolinium by conductivity-based approach

2020 ◽  
Vol 98 (10) ◽  
pp. 652-658
Author(s):  
R. Ananthanarayanan ◽  
M. Sivaramakrishna ◽  
B.S. Panigrahi
Keyword(s):  
Heavy Water ◽  
Ethylenediaminetetraacetic Acid ◽  
Limit Of Detection ◽  
Nuclear Industry ◽  
Complexing Agents ◽  
Complexing Agent ◽  
High Performing ◽  
New Class ◽  
Water Reactors

A conductivity-based technique is developed for the determination of Gd3+ in the heavy water moderators of pressurized heavy water reactors (PHWRs). The method involves monitoring extremely small shifts in conductivity, in the order of few nS/cm, due to the continuous addition of a suitable complexing agent to Gd3+ in aqueous medium. The resulting plot gives two distinct regions with vastly differing slopes. Two multidentate ligands, ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaaceticacid (DTPA), as complexing agents are compared. A high performing conductivity detector based on a new class of sensors called pulsating sensors that works entirely in the digital domain is deployed to monitor the conductivity shifts. Titration plots are studied in both H2O and D2O, and the observed difference between the plots in the two matrices is discussed in detail. Boron did not interfere in the analysis. The method was validated using the UV–vis spectrophotometric technique. The method is sensitive and rapid, as each analysis takes 3 min. The limit of detection in H2O and D2O are 1.27×10−7 mol/L and 5.1×10−7 mol/L, respectively. The precision in analysis lies between 1.9% and 5.3%. This method has important application in the nuclear industry for the routine analysis of gadolinium.

Chemical Mechanical Planarization of Cu Pattern Wafer Based Alkaline Slurry in GLSI with R(NH2)n as Complexing Agent

2011 ◽  
Vol 183-185 ◽  
pp. 2275-2278
Author(s):  
Yan Gang He ◽  
Jia Xi Wang ◽  
Xin Huan Niu ◽  
Xiao Wei Gan ◽  
Rui Shi ◽  
...  
Keyword(s):  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Complexing Agent

Chemical mechanical planarization (CMP) of Cu pattern wafer based alkaline Cu slurry in GLSI was investigated. The performance of Cu removal rate and dishing condition were discussed in this paper. Different formation of alkali CMP slurry (Cu1 and Cu2 slurry) were observed by removal rate experiments and showed that alkaline slurry provided a robust polishing performance on initial removal rate, which Cu1 and Cu2 slurry were higher than that of commercial acidity slurry, and in addition, alkaline slurry also have good ending removal rate both in Cu1 and Cu2 slurry and favorable dishing in Cu2 slurry. Furthermore, the result indicated that Cu alkaline slurry with a complexing agent of R(NH2)n, compared with commercial acidity slurry with a inhibitor of Benzotriazol (BTA), have better application foreground for 45nm nod and more advanced nodes.

scholarly journals Urea as a complexing agent for selective removal of Ta and Cu in sodium carbonate based alumina CMP slurry

2021 ◽  
pp. 49-49
Author(s):  
Arpita Shukla ◽  
Victoria Selvam ◽  
Manivannan Ramachandran
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Sodium Carbonate ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Corrosion Current ◽  
Complexing Agent ◽  
Downward Pressure

This work reports urea as a promising complexing agent in sodium carbonate (Na2CO3) based alumina slurry for chemical mechanical planarization (CMP) of tantalum (Ta) and copper (Cu). Ta and Cu were polished using Na2CO3 (1 wt.%) with alumina (2 wt.%) in the presence and absence of urea. The effect of slurry pH, urea concentration, applied downward pressure and platen rotational speed were deliberated and the outcomes were conveyed. Prior to the addition of urea, Ta removal rate (RR) was observed to enhance with pH from acidic to alkaline having maximum RR at pH 11. However, Cu RR decreases with increasing pH with minimum RR at pH 11. With the addition of urea in the slurry, Cu to Ta removal rate selectivity of nearly 1:1 is encountered at pH 11. The addition of urea boosts the Ta RR and suppresses Cu RR at the same time at 11 pH, as it adsorbs on the metal surface. Potentiodynamic polarization was conducted to determine the corrosion current (Icorr) and the corrosion potential (Ecorr). The electrochemical impedance spectroscopy (EIS) of both the metals was carried out in the proposed formulation and the obtained outcomes were elaborated.

Challenges and Rewards of Low-Abrasive Copper CMP: Evaluation and Integration for Single-Damascene Cu/Low-k Interconnects for the 90nm Node

2004 ◽  
Vol 816 ◽  
Author(s):  
Christopher L. Borst ◽  
Stanley M. Smith ◽  
Mona Eissa
Keyword(s):  
High Performance ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Low Dielectric ◽  
Process Characterization ◽  
Rate Profile ◽  
Feature Scale ◽  
Cu Cmp ◽  
Low K ◽  
Successful Integration

AbstractLow-abrasive content slurries for copper (Cu) chemical-mechanical planarization (CMP) have been developed to achieve removal rate and removal uniformity comparable to conventional slurries. They can improve post-CMP defectivity, improve topography and allow operation at lower polish pressures that are more compatible with the low-dielectric constant (low-k) materials required for current and future high-performance interconnects. Integration of these slurries into a yielding product with 9-level Cu/low-k metallization requires fundamental learning and process characterization. This paper discusses the some of the challenges encountered during development, integration, and qualification of a low-abrasive Cu CMP process for Texas Instruments (TI) Incorporated's 90 nm technology node with copper/organosilicate interconnect. As abrasive content is reduced, the slurry chemistry must play a larger role in CMP removal. A more aggressive reactive chemical formulation requires an effective inhibitive component to keep Cu static etch rate low. As a result, wafer-scale process and consumable interactions, die-scale planarization efficiency, and feature-scale removal rates each become more sensitive to process changes. Pressure and temperature have larger effects on removal rate/profile than conventional slurries, and complete clearing of Cu puddled over underlying topography becomes more difficult. Successful integration of these slurries, however, can achieve excellent results in dishing and erosion topography, Cu thickness uniformity, and Cu loss in small features such as vias and landing pads. Low-abrasive content solutions are also more stable and easy to handle in slurry distribution vessels and lines, have lower scratch and residue defectivity, and have greatly extended margin for overpolish. As lowabrasive content Cu slurry options continue to evolve to become manufacturable solutions, their benefits far outweigh the costs and challenges encountered in their successful integration.

A Review on Chemical Mechanical Planarization of Barrier Layer Metals

2021 ◽  
Vol 882 ◽  
pp. 171-180
Author(s):  
Arpita Shukla ◽  
S. Noyel Victoria ◽  
R. Manivannan
Keyword(s):  
Barrier Layer ◽  
Material Removal ◽  
Semiconductor Device ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Abrasive Particle ◽  
Mechanical Action ◽  
Complexing Agent ◽  
Whole Process ◽  
Front End

Chemical mechanical planarization (CMP) is recognized to be one of the finest polishing techniques which provides a smooth and globally planarized metal surface in the field of semiconductor device manufacturing. This process aids in material removal followed with a well finished and planarized surface by a combination of both chemical and mechanical action imparted by oxidizer and abrasive particle respectively. Semiconductor device manufacturing process is an amalgamation of two sub processes i.e. front end of line (FEOL) and back end of line (BEOL). The whole process consists of different segments comprising of several types of material that need to be planarized. The slurry components play an imperative role in metal CMP. It comprises abrasive, oxidizer, and several additives such as complexing agent, corrosion inhibitor, pH adjustor, slurry stabilizer, etc. and each imparts diverse impact on the material needs to be polished. One of the main topics of concern in this area is the removal rate selectivity of interconnects metal to the barrier layer metal. Thus, the reported review work efforts to emphasize the planarization of barrier layer materials, the various key ingredients employed in metal CMP and removal rate selectivity between interconnects and barrier layer metal.

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