Effect and mechanism analysis of sarcosine on the chemical mechanical polishing performance of copper film for GLSI

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To prevent excessive corrosion caused by the slurry in the copper (Cu) chemical mechanical polishing (CMP) process, a corrosion inhibitor is normally required. In this study, the methionine (Met) derivative FMOC-L-Methionine (Fmoc-Met-OH) was explored as a corrosion inhibitor for Cu film CMP in weak alkaline conditions (pH = 8.5). A comprehensive evaluation was conducted to confirm the efficiency of Fmoc-Met-OH as a corrosion inhibitor, combining experiments and theoretical calculations. The results showed that Fmoc-Met-OH could effectively inhibit the corrosion of Cu, with a high inhibition efficiency (IE) of 78.26% while maintaining a high removal rate (RR) of 5703 Å min−1, a low static etch rate (SER) of 676 Å min−1, and a low surface root mean square deviation (Sq) of 1.41 nm. Simultaneously, the results of X-ray photoelectron spectroscopy (XPS) tests and electrochemical analysis confirm that Fmoc-Met-OH molecules can form a dense and ordered adsorption film on the Cu surface. According to the density functional theory (DFT) calculations and molecular dynamics (MD) simulation, it was verified that Fmoc-Met-OH exhibited strong chemical adsorption on Cu substrates, as evidenced by the high binding energy (E Binding) value, low energy gap (ΔE), and radial distribution function (RDF) analysis. The findings provided theoretical evidence of the better inhibition effectiveness of Fmoc-Met-OH at a molecular or atomic level.

Section: Resultsmentioning

confidence: 96%

Surface Interaction Effect and Mechanism of Methionine Derivatives as Novel Inhibitors for Alkaline Copper CMP: Insights from Molecular Simulation and Experimental Analysis

Zhan,

Niu,

Liu

et al. 2023

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“…Surface quality analysis.-The increase of inhibition efficiency contributes to the improvement of the polished wafers surface quality. 45 Therefore, the surface tests are carried out on Cu wafers after polishing using the slurry with and without inhibitors. Figure 7 presents the surface morphology and root-mean-square surface roughness (Sq) of polished Cu wafers.…”

Section: Resultsmentioning

confidence: 99%

Multi-Scale Insight into Inhibition Mechanism of Benzo Derivatives in Chemical Mechanical Polishing of Copper Film Based on Experiments and Theoretical Calculations

Liu

Niu

Zhan

et al. 2023

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To protect the copper (Cu) surfaces from corrosion during chemical mechanical polishing (CMP), selecting appropriate inhibitors are critical. Benzo and its derivatives are potential superior inhibitors due to their diverse heteroatoms and environmentally friendliness. In this study, benzothiazole (ABT), 2-benzothiazolamine (2-ABT) and 2-aminobenzimidazole (2-ABI) were used as inhibitors to investigate the effect of molecular structure on the inhibition performance through experimental and theoretical calculation. With the addition of inhibitors, the removal rates were all inhibited effectively and the inhibition efficiency was in the following order: 2-ABI > 2-ABT > ABT. Electrochemical experiments and surface morphology tests demonstrated that the inhibitors could prevent corrosion by forming dense passivation film on Cu surfaces with a high inhibition efficiency of 88%, 94 %, and 95%, and improve the surface quality after CMP. Calculation results revealed that the introduction of amino groups (–NH2) and nitrogen(N) atom into five-membered ring enhanced the inhibition effect due to the larger adsorption energy, stronger ability to contribute electrons and denser passivation film which consistent with the experiment. Such study confirms the benzimidazole derivatives are potentially inhibitor for Cu film CMP and provides a new reference to design and select novel inhibitors.

“…The scanning range of open circuit voltage was ±0.3 V and the scanning speed was fixed at 5 mV s −1 during the test. 21 All cleaning experiments were performed using immersion contamination and immersion plus brushing for removal.…”

mentioning

confidence: 99%

Synergistic Effect of Complexing Agent TAD and Corrosion Inhibitor PZ on BTA Removal in Copper Post-CMP Cleaning

Wang,

Gao,

Zhang

et al. 2023

Self Cite

Benzotriazole (BTA) as a common corrosion inhibitor in the chemical mechanical polishing (CMP) process, can effectively protect the copper (Cu) surface, but its organic residues will form a passivation film on the wafer surface to prevent the contact between the cleaning solution and the wafer surface, so the removal of BTA is a major problem in the post-CMP cleaning. In this paper, N,N'-Bis(3-aminopropyl)-1,2-ethanediamine (TAD) and pyrazole (PZ) were used as the main components in the alkaline cleaning solution and fatty alcohol polyoxy ethylene ether was added as an auxiliary surfactant to investigate the removal of BTA. The complexation ability of TAD and the corrosion inhibition ability of PZ were verified by electrochemical experiments, and the reaction sites of the interaction between TAD and Cu surface were analyzed by quantum chemical calculations. Meanwhile, the mechanism of the synergistic removal of BTA by TAD and PZ was investigated by electrochemical methods. The final optimized cleaning solution consisted of 1 mmol/L TAD, 0.1 mmol/L PZ and 1 wt% JFCE and its good cleaning performance was verified by contact angle measurements, X-ray photoelectron spectroscopy and atomic force microscopy, which provided guidance for the development of the cleaning solution.