Molecular dynamics simulation of silicon oxidation enhanced by energetic hydrogen ion irradiation

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Precise control of silicon nitride (SiN) film quality is required for SiN plasma-enhanced atomic layer deposition (PEALD) processes. In this study, we examined the interactions of SiCl4 adsorbed Si surfaces with incident ions in the desorption/nitridation half-cycle of typical SiN PEALD with nitrogen plasma irradiation. Reactions of low-energy ion beams with Cl-terminated Si surfaces were investigated with in situ X-ray photoelectron spectroscopy. It was found that N2 + ion injection in the incident energy range of 30-100 eV formed a SiNx (x ≈ 1.33) layer on a Cl-terminated Si surface at room temperature. It was also confirmed that, although low-energy ion injection tends to remove Cl atoms from the surface, some Cl atoms are pushed into a deeper layer by knock-on collisions caused by incident ions. This observation indicates that the complete removal of Cl atoms from the surface by N2 + ion irradiation only is not feasible.

Section: Discussioncontrasting

confidence: 66%

“…Such transport of Cl atoms may be considered as ion-induced enhanced diffusion. 69) In the case of (a), i.e. 30 eV N 2 ion injection, the Cl intensity of the 45°takeoff angle is much higher than that of the 20°t akeoff angle at an ion dose of 5 × 10 15 ions cm −2 .…”

Section: Removal Of CL Atoms Frommentioning

confidence: 89%

Low-energy ion irradiation effects on chlorine desorption in plasma-enhanced atomic layer deposition (PEALD) for silicon nitride

Ito

Kita

Karahashi

et al. 2022

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“…The energy transfer from the incident ion to the dissociated species such as mobile H is considered to be efficient, and some similar kinetic effects are seen in molecular dynamics (MD) simulations. 25,75,76) 5.10. V b -dependence, γ H and implanted Ar + As shown in Fig.…”

Section: Kinetic Effect Of Mobile Hmentioning

confidence: 99%

Ion-induced interface defects in a-Si:H/c-Si heterojunction: possible roles and kinetics of hot mobile hydrogens

Nunomura

Tsutsumi

Nakane

et al. 2022

Interface defects in state-of-the-art semiconductors have a strong impact on device performance. These defects are often generated during device fabrication, in which a variety of plasma processing is used for deposition, etching and implantation. Here, we present the ion-induced defects in hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si) heterojunction. The experiments of argon ion (Ar+) irradiation over an a-Si:H/c-Si stack are systematically performed. The results suggest that the defects are generated not only by the impact of Ar+ (i.e. well-known effects), but also by another unique effect associated with “hot” mobile hydrogens (H). The mobile H atoms generated near the a-Si:H surface by the impact of Ar+ diffuse deeper, and they generate the a-Si:H/c-Si interface defects such as dangling bonds. The diffusion length of mobile H is determined to be 2.7 ± 0.3 nm, which indicates efficient reactions of mobile H with weak bonds in an a-Si:H network structure.

“…To understand the mechanism causing this variation and predict the process conditions for realizing good coverage and film properties, simulation technology is an useful tool. To date, on the micro scale (order of angstrom), molecular dynamics (MD) calculations [39][40][41][42][43][44][45][46][47][48][49][50][51][52][53] and first-principles calculations [54][55][56][57][58][59][60][61][62][63] have been studied for the etching and deposition processes of various films. In the case of SiN deposition films, Guo et al 53) investigated the kinetics of the early stage of a SiN deposition process via MD calculations of the 8 × 8 nm domain region with Lennard-Jones-type potentials.…”

Section: Introductionmentioning

confidence: 99%

Modeling and simulation of coverage and film properties in deposition process on large-scale pattern using statistical ensemble method

Kuboi

Matsugai

Tatsumi

et al. 2023

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This study modeled deposition processes using statistical ensemble and feature scale voxel methods to predict the coverage and film properties on a large-scale pattern for the first time. Certain new concepts, such as the use of probabilities to express physical and chemical phenomena occurring on the surface, interaction among voxels, and super particles for fast calculations, were introduced. Further, the model was used to analyze the experimental characteristic variation between the morphology and film density of SiN in low-temperature plasma-enhanced chemical vapor deposition using a SiH4/NH3/N2 gas mixture with different SiH4 flow rates, which has not been found in SiO2 films. The simulation results demonstrated the effect of precursor mass in the gas phase on the surface migration and morphology formation. In addition, a short residence time was required to prevent generation of large and heavy precursors for realizing good SiN coverage and film properties at the low temperature.