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Title: Mechanistic study of atomic layer deposition of Al{sub x}Si{sub y}O thin film via in-situ FTIR spectroscopy

A study of surface reaction mechanism on atomic layer deposition (ALD) of aluminum silicate (Al{sub x}Si{sub y}O) was conducted with trimethylaluminum (TMA) and tetraethoxysilane (TEOS) as precursors and H{sub 2}O as the oxidant. In-situ Fourier transform infrared spectroscopy (FTIR) was utilized to elucidate the underlying surface mechanism that enables the deposition of Al{sub x}Si{sub y}O by ALD. In-situ FTIR study revealed that ineffective hydroxylation of the surface ethoxy (–OCH{sub 2}CH{sub 3}) groups prohibits ALD of SiO{sub 2} by TEOS/H{sub 2}O. In contrast, effective desorption of the surface ethoxy group was observed in TEOS/H{sub 2}O/TMA/H{sub 2}O chemistry. The presence of Al-OH* group in vicinity of partially hydroxylated ethoxy (–OCH{sub 2}CH{sub 3}) group was found to propagate disproportionation reaction, which results in ALD of Al{sub x}Si{sub y}O. The maximum thickness from incorporation of SiO{sub x} from alternating exposures of TEOS/H{sub 2}O chemistry in Al{sub x}Si{sub y}O was found to be ∼2 Å, confirmed by high resolution transmission electron microscopy measurements.
Authors:
; ; ;  [1]
  1. Department of Chemical and Biomolecular Engineering, UCLA, Los Angeles, California 90095 (United States)
Publication Date:
OSTI Identifier:
22479654
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 33; Journal Issue: 5; Other Information: (c) 2015 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 42 ENGINEERING; ALUMINIUM SILICATES; CHEMICAL REACTION KINETICS; DEPOSITION; DESORPTION; FOURIER TRANSFORM SPECTROMETERS; FOURIER TRANSFORMATION; HYDROXYLATION; INFRARED SPECTRA; OXIDATION; SILICON OXIDES; SPECTROSCOPY; SURFACES; THICKNESS; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; WATER