1
|
Chowdhury T, Khumaini K, Hidayat R, Kim HL, Lee WJ. Chemisorption of silicon tetrachloride on silicon nitride: a density functional theory study. Phys Chem Chem Phys 2024; 26:11597-11603. [PMID: 38536050 DOI: 10.1039/d3cp05799b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2024]
Abstract
We studied the chemisorption of silicon tetrachloride (SiCl4) on the NH2/NH-terminated silicon nitride slab model using density functional theory (DFT) for atomic layer deposition (ALD) of silicon nitride. Initially, two reaction pathways were compared, forming HCl or NH3+Cl- as a byproduct. The NH3+Cl- complex formation was more exothermic than the HCl formation, with an activation energy of 0.26 eV. The -NH2* reaction sites are restored by desorption of HCl from the NH3+Cl- complexes at elevated temperatures of 205 °C or higher. Next, three sequential ligand exchange reactions forming Si-N bonds were modeled and simulated. The reaction energies became progressively less exothermic as the reaction progressed, from -1.31 eV to -0.30 eV to 0.98 eV, due to the stretching of Si-N bonds and the distortion of the N-Si-N bond angles. Also, the activation energies for the second and third reactions were 2.17 eV and 1.55 eV, respectively, significantly higher than the 0.26 eV of the first reaction, mainly due to the additional dissociation of the N-H bond. The third Si-N bond formation is unfavorable due to the endothermic reaction and higher activation energy. Therefore, the chemisorbed species would be -SiCl2* when the surface is exposed to SiCl4.
Collapse
Affiliation(s)
- Tanzia Chowdhury
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, Republic of Korea
| | - Khabib Khumaini
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, Republic of Korea
- Department of Chemistry, Universitas Pertamina, Jakarta 12220, Indonesia
| | - Romel Hidayat
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, Republic of Korea
- Metal-organic Compounds Materials Research Center, Sejong University, Seoul, 05006, Republic of Korea.
| | - Hye-Lee Kim
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, Republic of Korea
- Metal-organic Compounds Materials Research Center, Sejong University, Seoul, 05006, Republic of Korea.
| | - Won-Jun Lee
- Department of Nanotechnology and Advanced Materials Engineering, Sejong University, Seoul, 05006, Republic of Korea
- Metal-organic Compounds Materials Research Center, Sejong University, Seoul, 05006, Republic of Korea.
| |
Collapse
|
2
|
Vasiliev VY. COMPOSITION, STRUCTURE, AND FUNCTIONAL PROPERTIES OF THIN SILICON NITRIDE FILMS GROWN BY ATOMIC LAYER DEPOSITION FOR MICROELECTRONIC APPLICATIONS (REVIEW OF 25 YEARS OF RESEARCH). J STRUCT CHEM+ 2022. [DOI: 10.1134/s0022476622070022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
3
|
Remote Plasma Atomic Layer Deposition of SiNx Using Cyclosilazane and H2/N2 Plasma. APPLIED SCIENCES-BASEL 2019. [DOI: 10.3390/app9173531] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Silicon nitride (SiNx) thin films using 1,3-di-isopropylamino-2,4-dimethylcyclosilazane (CSN-2) and N2 plasma were investigated. The growth rate of SiNx thin films was saturated in the range of 200–500 °C, yielding approximately 0.38 Å/cycle, and featuring a wide process window. The physical and chemical properties of the SiNx films were investigated as a function of deposition temperature. As temperature was increased, transmission electron microscopy (TEM) analysis confirmed that a conformal thin film was obtained. Also, we developed a three-step process in which the H2 plasma step was introduced before the N2 plasma step. In order to investigate the effect of H2 plasma, we evaluated the growth rate, step coverage, and wet etch rate according to H2 plasma exposure time (10–30 s). As a result, the side step coverage increased from 82% to 105% and the bottom step coverages increased from 90% to 110% in the narrow pattern. By increasing the H2 plasma to 30 s, the wet etch rate was 32 Å/min, which is much lower than the case of only N2 plasma (43 Å/min).
Collapse
|
4
|
Owusu-Ansah E, Rajendran A, Shi Y. Catalytic dissociation of tris(dimethylamino)silane on hot tungsten and tantalum filament surfaces. Phys Chem Chem Phys 2019; 21:14357-14365. [PMID: 30714585 DOI: 10.1039/c8cp06669h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The dissociation of tris(dimethylamino)silane (TrDMAS) on hot tungsten and tantalum surfaces was studied under collision-free conditions. The products from the hot-wire decomposition of TrDMAS were monitored using a 10.5 eV vacuum ultraviolet laser single-photon ionization in tandem with time-of-flight mass spectrometry. Formation of a methyl radical and N-methyl methyleneimine (NMMI) was detected. A transition from a surface reaction rate-limiting regime at filament temperatures lower than 1800-2000 °C to mass transport regime at higher temperatures (>1800-2000 °C) was observed for the formation of both products. In the surface reaction regime, the Arrhenius behavior was followed in two separate temperature regions with different activation energies. It was found that low temperatures (900-1300 °C) favor the production of the methyl radical and high temperatures (1400-2000 °C) favor the production of NMMI with lower activation energies. A theoretical investigation using ab initio calculations of the concerted and stepwise formation of NMMI along with the homolytic cleavages of N-CH3 and Si-H in the gas phase has shown that the concerted pathway to form NMMI is the most energetically favorable one of all four routes with an activation barrier of 328 kJ mol-1. The lower activation energy values determined experimentally for the formation of NMMI and ˙CH3 as compared to those obtained from theoretical calculations indicate that the dissociation of TrDMAS, an N-containing organosilicon molecule, on the W and Ta surfaces is a catalytic cracking process.
Collapse
Affiliation(s)
- Ebenezer Owusu-Ansah
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
| | - Arun Rajendran
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
| | - Yujun Shi
- Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N 1N4.
| |
Collapse
|