Unraveling the selective etching mechanism of silicon nitride over silicon dioxide by phosphoric acid: First-principles study

Park, Soyong; Jung, Hunsang; Min, K.; Kim, Junyeop; Han, Byungchan

doi:10.1016/j.apsusc.2021.149376

Cited by 12 publications

(5 citation statements)

References 49 publications

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“…We estimated the average time ( t avg ) for the fluorination of SiO 2 or Si at 25 °C by eqn (15) using transition state theory: 11,46,47 where k is the reaction rate constant, k B is the Boltzmann constant, T is room temperature, h is Planck's constant, and the Δ ‡ G ° is the standard free energy of activation. We computed the standard free energy of activation values by the free energy change from the reactant state to the transition state.…”

Section: Resultsmentioning

confidence: 99%

Selective etching mechanism of silicon oxide against silicon by hydrogen fluoride: a density functional theory study

Hidayat

Kim

Khumaini

et al. 2023

Phys. Chem. Chem. Phys.

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Section: Resultsmentioning

confidence: 99%

Selective etching mechanism of silicon oxide against silicon by hydrogen fluoride: a density functional theory study

Hidayat

Kim

Khumaini

et al. 2023

Phys. Chem. Chem. Phys.

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“…Second, a highly selective and dissolving nitride etchant is required to create a uniform 3D structure for VNAND or other 3D stacking devices. [58][59][60] Currently, 3D structures are created by the selective removal of nitride films, while oxide films are completely protected. Therefore, etch-controllable and highly diffusive nitride etchants will be more effective in creating a 3D Figure 6.…”

Section: Growth Of Importance Of Semiconductor Materialsmentioning

confidence: 99%

“…Selective ALD deposition is expected to replace the traditional semiconductor patterning processes of deposition, lithography, and etching steps in some layers. Additionally, highly uniform and ultrathin high-k ALD film technologies will be very beneficial for the DRAM capacitor fabrication process because of the high aspect ratio of the pillar features of future DRAM capacitors.Second, a highly selective and dissolving nitride etchant is required to create a uniform 3D structure for VNAND or other 3D stacking devices [58][59][60]. Currently, 3D structures are created by the selective removal of nitride films, while oxide films are completely protected.…”

mentioning

confidence: 99%

Creating the Future with Silicon

Jung

2023

Adv Materials Technologies

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The rise of AI technology, the expansion of smart and connected devices, and the COVID‐19 global pandemic have driven a change in the nature of social interactions from face‐to‐face to contact‐free/remote, which has tremendously increased the demand for various semiconductor devices. However, scaling and performance improvement of semiconductor devices are becoming more difficult every year, and extensive studies have been conducted to overcome these technological roadblocks. This paper reviews the present state of semiconductor development and discusses several approaches to overcome these scaling and performance limitations. Additionally, the importance of collaboration and the related ecosystem is emphasized to strengthen the cooperation among semiconductor stakeholders and support further semiconductor development.

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“…The primary approach for developing 3D NAND is increasing the number of Si 3 N 4 /SiO 2 multistack layers (Figure a). − However, with the growing stacking of the pair layers, the dielectric SiO 2 layers are susceptible to dissolution by the hot-concentrated phosphoric acid (PA) solution, which is the etchant for the selective Si 3 N 4 etching process (Figure b). − The resultant thinning of SiO 2 layers (Figure c) disrupts the feasibility of subsequent processes . To inhibit SiO 2 etching, additives are considered a promising approach presently.…”

Section: Introductionmentioning

confidence: 99%

Study on the SiO₂ Wet-Etching Mechanism Using γ-Ureidopropyltriethoxysilane as an Inhibitor for 3D NAND Fabrication

Zhou,

Han,

et al. 2024

ACS Appl. Electron. Mater.

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The SiO 2 layers, as the dielectric in the multistack storage cells of 3D NAND, are detrimentally dissolved by phosphoric acid (PA) during the selective Si 3 N 4 etching. The thinning of SiO 2 layers leads to the failure of subsequent processes; thus, an etching inhibitor for SiO 2 is crucial for 3D NAND fabrication. However, most inhibitors are currently limited to neutral or alkaline solutions. In this work, the γ-ureidopropyltriethoxysilane (UPTES), compatible with a hot-concentrated PA solution, was applied to the wet-etching process for the first time and exhibited an inhibitory effect on SiO 2 etching by retarding the etch rate over 60% without affecting the Si 3 N 4 etching. The saturation adsorption of UPTES on the SiO 2 substrate is confirmed to occur around the critical concentration, according to the Langmuir−Freundlich adsorption isotherm. The adsorption behavior of UPTES exhibits a reliance on its concentration. Around the critical concentration, the UPTES molecules chemisorb on the SiO 2 surface by Si−O−Si covalent bonds to form ordered UPTESsiloxane layers, avoiding contact between SiO 2 and the etchant; whereas oversaturated UPTES polymers physisorb not only on SiO 2 but also on Si 3 N 4 , impeding the Si 3 N 4 etching. This work contributes to a step forward in the effective wet-etching process in highdensity 3D NAND fabrication.

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Unraveling the selective etching mechanism of silicon nitride over silicon dioxide by phosphoric acid: First-principles study

Cited by 12 publications

References 49 publications

Selective etching mechanism of silicon oxide against silicon by hydrogen fluoride: a density functional theory study

Selective etching mechanism of silicon oxide against silicon by hydrogen fluoride: a density functional theory study

Creating the Future with Silicon

Study on the SiO₂ Wet-Etching Mechanism Using γ-Ureidopropyltriethoxysilane as an Inhibitor for 3D NAND Fabrication

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Unraveling the selective etching mechanism of silicon nitride over silicon dioxide by phosphoric acid: First-principles study

Cited by 12 publications

References 49 publications

Selective etching mechanism of silicon oxide against silicon by hydrogen fluoride: a density functional theory study

Selective etching mechanism of silicon oxide against silicon by hydrogen fluoride: a density functional theory study

Creating the Future with Silicon

Study on the SiO2 Wet-Etching Mechanism Using γ-Ureidopropyltriethoxysilane as an Inhibitor for 3D NAND Fabrication

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Product

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Study on the SiO₂ Wet-Etching Mechanism Using γ-Ureidopropyltriethoxysilane as an Inhibitor for 3D NAND Fabrication