Tungsten passivation layer (WO3) formation mechanisms during chemical mechanical planarization in the presence of oxidizers

Poddar, Maneesh Kumar; Jalalzai, Palwasha; Sahir, Samrina; Yerriboina, Nagendra Prasad; Kim, Tae-Gon; Park, Jin-Goo

doi:10.1016/j.apsusc.2020.147862

Cited by 22 publications

(12 citation statements)

References 17 publications

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“…In the NPM cleaning solution, both H 2 O 2 and NO 3 − can produce a strong oxidizing radical −•OH, which helps cut the Ce-O-Si bond. 11,20,21 To quantitatively analyze the effect of the •OH, we use p-nitrosodimethylaniline (PNDA), which is a well-known hydroxyl radical trapping agent as an indicator of •OH. The reaction equation of PNDA with OH radical is shown in Eq.…”

Section: Discussionmentioning

confidence: 99%

“…4. 11,[20][21][22][23][24] PNDA has a strong characteristic absorption peak at 440 nm, and the hydroxyl radicals are easily consumed by PNDA to form PNDA-OH, which has a much weaker absorbance at 440 nm. It is found that acid would result in the decrease of the PNDA peak.…”

Section: Discussionmentioning

confidence: 99%

“…The negative sign corresponds to the reduction of PNDA concentration with time. 11,21 The decrease of PNDA concentration caused by the reaction of PNDA and •OH will reduce its peak intensity. When the concentration of PNDA does not change, it can be considered that a steady-state value has been reached.…”

Section: Discussionmentioning

confidence: 99%

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Cleaning Nanoceria Particles by Diluted HNO₃ with H₂O₂ Mixture (NPM) Solution at Different Temperatures

Wang¹,

Wu²,

Qiu³

et al. 2023

ECS J. Solid State Sci. Technol.

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It is difficult to remove nanoceria abrasives from the SiO2 substrate after the shallow trench isolation (STI) chemical mechanical polishing process. In this work, we studied the cleaning behavior of ceria particles by using an acidic cleaning solution instead of normal sulfuric acid and hydrogen peroxide mixture solution (SPM) at high temperatures (above 85℃) and low temperatures (below 30℃). The solution, named as NPM, consists of HNO3 (1-2 vol%), H2O2 (5-10 vol %), and deionized water (DIW). It is found that NPM may dis-solve nanoceria particles at high temperatures with higher cleaning efficiency (CE) than that of SPM. NPM can clean the A90 (90 nm ceria) particles under ultrasonic/megasonic at low temperatures, while SPM has poor CE at 20℃. The redox reaction of NPM and its effect on cleaning mechanism were systematically studied.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Cleaning Nanoceria Particles by Diluted HNO₃ with H₂O₂ Mixture (NPM) Solution at Different Temperatures

Wang¹,

Wu²,

Qiu³

et al. 2023

ECS J. Solid State Sci. Technol.

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“…In order to achieve high-efficiency and high-quality polishing, researchers have conducted extensive research on tungsten polishing methods and processes. Poddar et al [ 14 ] used a mixed oxidant composed of H 2 O 2 and Fe(NO 3 ) 3 for chemical–mechanical polishing of tungsten and found that the mixed oxidant would generate OH with stronger oxidizing ability, and its removal efficiency was higher than that of a single oxidant. Lim et al [ 15 ] found that the polishing rate could be divided into two regions with increases in Fe(NO 3 ) 3 concentration; when Fe(NO 3 ) 3 concentration was less than 0.1 wt.%, the polishing rate of tungsten increased rapidly, while when the Fe(NO 3 ) 3 concentration was higher than 0.1 wt.%, the polishing rate increased slowly.…”

Section: Introductionmentioning

confidence: 99%

Effects of pH Values and H2O2 Concentrations on the Chemical Enhanced Shear Dilatancy Polishing of Tungsten

Wang

Chen

et al. 2022

Micromachines

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In order to obtain tungsten with great surface qualities and high polishing efficiency, a novel method of chemical enhanced shear dilatancy polishing (C-SDP) was proposed. The effects of pH values and H2O2 concentrations on the polishing performance of tungsten C-SDP were studied. In addition, the corrosion behaviors of tungsten in solutions with different pH values and H2O2 concentrations were analyzed by electrochemical experiments, and the valence states of elements on the tungsten surface were analyzed by XPS. The results showed that both pH values and H2O2 concentrations had significant effects on tungsten C-SDP. With the pH values increasing from 7 to 12, the MRR increased from 6.69 µm/h to 13.67 µm/h. The optimal surface quality was obtained at pH = 9, the surface roughness (Ra) reached 2.35 nm, and the corresponding MRR was 9.71 µm/h. The MRR increased from 9.71 µm/h to 34.95 µm/h with the H2O2 concentrations increasing from 0 to 2 vol.%. When the concentration of H2O2 was 1 vol.%, the Ra of tungsten reached the lowest value, which was 1.87 nm, and the MRR was 26.46 µm/h. This reveals that C-SDP technology is a novel ultra-precision machining method that can achieve great surface qualities and polishing efficiency of tungsten.

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“…3 H 2 O 2 and citric acid are the commonly used oxidizer and complexing agent, respectively, for the cobalt CMP slurries. [4][5][6][7][8][9] Cobalt undergoes accelerated dissolution in acidic media but passivates in neutral to alkaline conditions. To control the corrosion, specialized azole-based compounds such as BTA, MBTA, TAZ, etc., are used as corrosion inhibitors.…”

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confidence: 99%

Effect of Slurry Additives on Co-BTA Complex Stability and Inhibition Property During Co CMP Process

Jalalzai

Ryu

Sahir

et al. 2022

ECS J. Solid State Sci. Technol.

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The stability of the cobalt surface after the chemical mechanical planarization process is crucial to prevent the corrosion of the surface during the wafer transfer step. The stability of the Co-BTA complex is investigated in this work by using various experimental and surface analysis techniques. The higher inhibition efficiency of the Co-BTA complex observed at pH 7 was further investigated, and a more passive Co surface was observed during the de-ionized water (DIW) rinsing step. The low stability of the Co-BTA complex in the presence of slurry additives was confirmed from the accelerated oxidative dissolution of the Co surface compared to the adsorption of BTA. Ex-situ electrochemical impedance spectroscopy was further performed to analyze the stability of the Co-BTA complex to confirm the passivation of Co during the DIW rinsing step. The corrosion resistance of the Co surface during the rinsing step is further enhanced by reducing the dissolved oxygen content.

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Tungsten passivation layer (WO3) formation mechanisms during chemical mechanical planarization in the presence of oxidizers

Cited by 22 publications

References 17 publications

Cleaning Nanoceria Particles by Diluted HNO₃ with H₂O₂ Mixture (NPM) Solution at Different Temperatures

Cleaning Nanoceria Particles by Diluted HNO₃ with H₂O₂ Mixture (NPM) Solution at Different Temperatures

Effects of pH Values and H2O2 Concentrations on the Chemical Enhanced Shear Dilatancy Polishing of Tungsten

Effect of Slurry Additives on Co-BTA Complex Stability and Inhibition Property During Co CMP Process

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Tungsten passivation layer (WO3) formation mechanisms during chemical mechanical planarization in the presence of oxidizers

Cited by 22 publications

References 17 publications

Cleaning Nanoceria Particles by Diluted HNO3 with H2O2 Mixture (NPM) Solution at Different Temperatures

Cleaning Nanoceria Particles by Diluted HNO3 with H2O2 Mixture (NPM) Solution at Different Temperatures

Effects of pH Values and H2O2 Concentrations on the Chemical Enhanced Shear Dilatancy Polishing of Tungsten

Effect of Slurry Additives on Co-BTA Complex Stability and Inhibition Property During Co CMP Process

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Product

Resources

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Cleaning Nanoceria Particles by Diluted HNO₃ with H₂O₂ Mixture (NPM) Solution at Different Temperatures

Cleaning Nanoceria Particles by Diluted HNO₃ with H₂O₂ Mixture (NPM) Solution at Different Temperatures