Effects of Additives in KOH Based Electrolytes on Cu ECMP

2007 ◽  
Vol 991 ◽  
Author(s):  
Tae-Young Kwon ◽  
In-Kwon Kim ◽  
Jin-Goo Park
Keyword(s):  
Citric Acid ◽  
Applied Voltage ◽  
Counter Electrode ◽  
Corrosion Potential ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Corrosion Current ◽  
Dynamic State ◽  
Static State ◽  
Potentiodynamic Curves

ABSTRACTThe purpose of this study was to characterize KOH based electrolytes and effects of additives on electro-chemical mechanical planarization. The electrochemical mechanical polisher was made to measure the potentiodynamic curve and removal rate of Cu. The potentiodynamic curves were measured in static and dynamic states in investigated electrolytes using a potentiostat. Cu disk of 2 inch was used as a working electrode and Pt electroplated platen was used as a counter electrode. KOH was used as the electrolyte. H2O2 and citric acid were used as additives for the ECMP of Cu. In static and dynamic potentiodynamic measurements, the corrosion potential decreased and corrosion current increased as a function of KOH concentration. In dynamic state, different potentiodynamic curve was obtained when compared to the static state. The current density did not decrease in passivation region by mechanical polishing effect. The static etch and removal rate were measured as function of KOH concentration and applied voltage. In ECMP system, polishing was performed at 30 rpm and 1 psi. The removal rate was about 60 nm/min at 0.3 V when 5 wt% KOH was used. Also, the effect of additive was investigated in KOH based electrolyte on removal rates. As a result, The removal rate was increased to 350 nm/min when 5wt% KOH, 5vol% H2O2, 0.3 M citric acid were used.

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.

The Influence of Aggressive Environment with a High Content of Fluoride Ions on the Alloy TiAl6V4 with a Protective Ti-Al-Si Layer

2011 ◽  
Vol 287-290 ◽  
pp. 966-969
Author(s):  
Tomáš Kubatík ◽  
Marcela Kadlecová ◽  
Boleslav Eremiáš ◽  
Eva Kalabisová
Keyword(s):  
Chloride Solution ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Potential Range ◽  
Fluoride Ions ◽  
Electrochemical Tests ◽  
Aggressive Environment ◽  
Potentiodynamic Curves ◽  
Main Component ◽  
Positive Effect

This work presents results on the influence of fluoride ions on the behavior of layers whose main component is the phase TiAl0.3Si1.7 (called t2 phase), formed on TiAl6V4 substrate. Layers were prepared in AlSi20 melt at 650 ° C for 60 min. Potentiodynamic curves were measured in a chloride solution with 0 and 5000 ppm fluoride. Layer were shifted corrosion potential to more negative values and at the some time reduce the corrosion current density (Im). Values of Im are in the potential range of 300 – 1500 mV (SCE) for TiAl6V4 with Ti-Al-Si layers significantly lower in comparison with Im values found for TiAl6V4 in chloride solution containing 5000 F-. The electrochemical tests showed that Ti-Al-Si layer had marked positive effect on corrosion resistance of TiAl6V4 alloys in aggressive environment with high content of F-.

Effect of the Electrolytic Solution Composition on Properties of Ceramic Coatings on Ti Produced by PEO

2012 ◽  
Vol 174-177 ◽  
pp. 596-599
Author(s):  
Ping Yi Guo ◽  
Ning Wang ◽  
Peng Fan
Keyword(s):  
Applied Voltage ◽  
Corrosion Potential ◽  
Pure Titanium ◽  
Corrosion Current ◽  
Ceramic Coatings ◽  
Oxide Coatings ◽  
Solution Composition ◽  
Electrolytic Oxidation ◽  
State Growth ◽  
Plasma Electrolytic

Ceramic oxide coatings were produced on pure titanium by plasma electrolytic oxidation in different electrolytes. The variation of coating thickness with applied voltages revealed coating almost kept a steady-state growth rate in electrolyte A and B, but not for electrolyte C. Numerous nodules occurred on the surface of the coatings at 200V in electrolyte A and B, and then nodules disappeared with the applied voltage increasing to 300V. There was no nodules occurred, and pore size was evidently different in electrolyte C. When the applied voltage was 300V, the coating formed in electrolyte C exhibited the highest corrosion potential and lowest corrosion current density in 3.5% NaCl aqueous solution.

Al CMP for Low Resistance Gate Fill for 20nm and Beyond Replacement Metal Gate

2013 ◽  
Vol 1560 ◽  
Author(s):  
Laertis Economikos ◽  
Xing Zhang ◽  
Haigou Hwang ◽  
Unoh Kwon ◽  
Keith Wong ◽  
...  
Keyword(s):  
Corrosion Potential ◽  
Galvanic Corrosion ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Intermetallic Phase ◽  
Electrical Potential ◽  
Sulfonate Group ◽  
Metal Gate ◽  
Low Resistance ◽  
Pattern Density

ABSTRACTAluminum (Al) gate fill has been implemented in Replacement Metal Gate (RMG) due to its low resistivity. Titanium (Ti) has been widely used as wetting layer for Al to fill the gates. For low resistance gate fill in structures with small feature size and high aspect ratio, Ti-Al metal fill becomes increasingly more challenging as we move from 20nm into 14nm FinFET and 3D type structures.Cobalt (Co) is a good wetting film for Al with better fill performance and lower resistance than Ti-Al based process. However, due to the difference in corrosion potential between Al and Co, Chemical Mechanical Planarization (CMP) creates pitting type defects on Al-Co film that increases resistance variability across pattern density. CMP induced corrosion is separated in two parts; first is the static Co corrosion happened in the acidic chemical environment in the Al slurry. Second is the galvanic corrosion from Co-Al metal boundary due to high metal electrical potential. Static corrosion can be resolved by adding a Co corrosion inhibitor in the slurry formulation1. Galvanic corrosion can be minimized by controlling Co thickness deposition and formation of complete intermetallic phase. By controlling the removal rate with respect to corrosion rate we were able to suppress corrosion significantly.We looked into compositions where the corrosion potential (Ecorr) gap between Al and Co is reduced to ≤10mV leading to reduced galvanic currents. Stabilization of the corrosion currents in both Al and Co was observed using potentiodynamic scans. The effect of pH, several oxidizers and additives on the open circuit potentials (Eoc) of Al and Co was investigated and it was found that solutions of KMnO4, saccharides and sulfonate group containing compounds help reduce the Ecorr gap in between Al and Co to ∼10 mV.Controlling the Al gate height across pattern densities and gate lengths to within few nm is another challenge for Al CMP. The industry widely used approach is to clear all Al using a slurry with high selectivity to dielectric, followed by a CMP step using a non-selective Al-to-oxide slurry. Both polishing steps need to be optimized in parallel in order to remove the incoming spacer SiN divot, minimize Al loss on gates with high pattern density or long gate length, minimize oxide loss on large open areas while maintaining low defectivity.In this paper we are presenting an innovate Al CMP process that demonstrated low gate resistance with tight distribution up to 80% pattern density. This work has been supported by the independent Bulk CMOS and SOI technology development projects at the IBM Microelectronics Division Semiconductor Research & Development Center, Hopewell Junction, NY 12533.

High Planarization Efficiency and Wide Process Window Using Electro-chemical Mechanical Planarization (EcmpTM)

2005 ◽  
Vol 867 ◽  
Author(s):  
Feng Q Liu ◽  
Liang Chen ◽  
Alain Duboust ◽  
Stan Tsai ◽  
Antoine Manens ◽  
...  
Keyword(s):  
Applied Voltage ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Copper Film ◽  
Process Window ◽  
Factors Affecting ◽  
Profile Control ◽  
Planarization Process ◽  
Rate Controlled ◽  
Electrochemical Removal

AbstractEcmpTM is a revolutionary planarization technology uniquely combining removal rate controlled by charge with superior planarization efficiency in the near no shear regime. In addition, the electrochemical removal mechanism has excellent within-wafer profile control. Multiple electrical zones configuration combined with a precise end-point control by electric charge, make it more predictable to control the remaining thickness and profile of copper film. The factors affecting the planarization such as the concentration and the efficiency of the inhibitors will be discussed in this paper. Meanwhile a planarization mechanism for Ecmp will be proposed to match the high planarization efficiency. The effects of applied voltage on removal rate and planarization efficiency will be presented in this paper. The electrical feature allows Ecmp to be a planarization process with removal rate independent of down force, enabling a wide removal rate window based on applied voltage.

scholarly journals An electrochemical method to investigate the effects of compound composition on gold dissolution in thiosulfate solution

2020 ◽  
Vol 9 (1) ◽  
pp. 496-502 ◽  
Author(s):  
Zhaohui Zhang ◽  
Bailong Liu ◽  
Mei Wu ◽  
Longxin Sun
Keyword(s):  
Dissolution Rate ◽  
Current Density ◽  
Polarization Resistance ◽  
Electrochemical Method ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Gold Dissolution ◽  
Tafel Polarization ◽  
Edta Solution

AbstractThe electrochemical behavior of gold dissolution in the Cu2+–NH3–S2O32−–EDTA solution has been investigated in detail by deriving and analyzing the Tafel polarization curve, as this method is currently widely implemented for the electrode corrosion analysis. The dissolution rate of gold in Cu2+–NH3–S2O32−–EDTA solution was determined based on the Tafel polarization curves, and the effects of various compound compositions in a Cu2+–NH3–S2O32−–EDTA mixture on the corrosion potential and corrosion current density were analyzed. The results showed that the corrosion potential and polarization resistance decreased, whereas the corrosion current density increased for certain concentrations of S2O32−–NH3–Cu2+ and EDTA, indicating that the dissolution rate of gold had changed. The reason for promoting the dissolution of gold is also discussed.

scholarly journals Microstructure of Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn Alloys

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 37
Author(s):  
Wenzheng Chen ◽  
Wenlong Zhang ◽  
Dongyan Ding ◽  
Daihong Xiao
Keyword(s):  
Mechanical Properties ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Aging Treatment ◽  
Corrosion Current ◽  
Homogenization Temperature ◽  
Tafel Polarization ◽  
Al2cu Phase ◽  
Different Temperatures ◽  
Microstructural Optimization

Microstructural optimization of Al-Li alloys plays a key role in the adjustment of mechanical properties as well as corrosion behavior. In this work, Al-5Cu-1Li-0.6Mg-0.5Ag-0.5Mn alloy was homogenized at different temperatures and holding times, followed by aging treatment. The microstructure and composition of the homogenized alloys and aged alloys were investigated. There were Al7Cu4Li phase, Al3Li phase, and Al2CuLi phases in the homogenized alloys. The Al7Cu4Li phase was dissolved with an increase in homogenization temperature and holding time. Al2Cu phase and Al2CuLi phase coarsened during the homogenization process. The alloy homogenized at 515 °C for 20 h was subjected to a two-stage aging treatment. Peak-age alloy, which had gone through age treatment at 120 °C for 4 h and 180 °C for 6 h, was mainly composed of α-Al, Al20Cu2Mn3, Al2CuLi, Al2Cu, and Al3Li phases. Tafel polarization of the peak-age alloys revealed the corrosion potential and corrosion current density to be −779 mV and 2.979 μA/cm2, respectively. The over-age alloy had a more positive corrosion potential of −658 mV but presented a higher corrosion current of 6.929 μA/cm2.

scholarly journals Novel Abrasive-Impregnated Pads and Diamond Plates for the Grinding and Lapping of Single-Crystal Silicon Carbide Wafers

2021 ◽  
Vol 11 (4) ◽  
pp. 1783
Author(s):  
Ming-Yi Tsai ◽  
Kun-Ying Li ◽  
Sun-Yu Ji
Keyword(s):  
Silicon Carbide ◽  
Wear Rate ◽  
Single Crystal ◽  
Traditional Method ◽  
Removal Rate ◽  
Chemical Mechanical Planarization ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Diamond Grit ◽  
Ceramic Binder

In this study, special ceramic grinding plates impregnated with diamond grit and other abrasives, as well as self-made lapping plates, were used to prepare the surface of single-crystal silicon carbide (SiC) wafers. This novel approach enhanced the process and reduced the final chemical mechanical planarization (CMP) polishing time. Two different grinding plates with pads impregnated with mixed abrasives were prepared: one with self-modified diamond + SiC and a ceramic binder and one with self-modified diamond + SiO2 + Al2O3 + SiC and a ceramic binder. The surface properties and removal rate of the SiC substrate were investigated and a comparison with the traditional method was conducted. The experimental results showed that the material removal rate (MRR) was higher for the SiC substrate with the mixed abrasive lapping plate than for the traditional method. The grinding wear rate could be reduced by 31.6%. The surface roughness of the samples polished using the diamond-impregnated lapping plate was markedly better than that of the samples polished using the copper plate. However, while the surface finish was better and the grinding efficiency was high, the wear rate of the mixed abrasive-impregnated polishing plates was high. This was a clear indication that this novel method was effective and could be used for SiC grinding and lapping.

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.

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