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Title: Characterization of plasma-enhanced atomic layer deposition of Al{sub 2}O{sub 3} using dimethylaluminum isopropoxide

In this research, Al{sub 2}O{sub 3} films were grown by remote plasma-enhanced atomic layer deposition using a nonpyrophoric precursor, dimethylaluminum isopropoxide (DMAI), and oxygen plasma. After optimization, the growth rate was determined to be ∼1.5 Å/cycle within a growth window of 25–220 °C; the higher growth rate than reported for thermal atomic layer deposition was ascribed to the higher reactivity of the plasma species compared with H{sub 2}O and the adsorption of active oxygen at the surface, which was residual from the oxygen plasma exposure. Both effects enhance DMAI chemisorption and increase the saturation density. In addition, a longer oxygen plasma time was required at room temperature to complete the reaction and decrease the carbon contamination below the detection limit of x-ray photoemission spectroscopy. The properties of the subsequent Al{sub 2}O{sub 3} films were measured for different temperatures. When deposited at 25 °C and 200 °C, the Al{sub 2}O{sub 3} films demonstrated a single Al-O bonding state as measured by x-ray photoemission spectroscopy, a similar band gap of 6.8±0.2 eV as determined by energy loss spectroscopy, a similar index of refraction of 1.62±0.02 as determined by spectroscopic ellipsometry, and uniform growth with a similar surface roughness before and after growth as confirmed by atomic forcemore » microscopy. However, the room temperature deposited Al{sub 2}O{sub 3} films had a lower mass density (2.7 g/cm{sup 3} compared with 3.0 g/cm{sup 3}) and a higher atomic ratio of O to Al (2.1 compared with 1.6) as indicated by x-ray reflectivity and Rutherford backscattering spectroscopy, respectively.« less
Authors:
; ;  [1] ;  [2]
  1. Department of Physics, Arizona State University, Tempe, Arizona 85287-1504 (United States)
  2. School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287-6106 (United States)
Publication Date:
OSTI Identifier:
22258637
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 32; Journal Issue: 2; Other Information: (c) 2014 American Vacuum Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ALUMINIUM OXIDES; ATOMIC FORCE MICROSCOPY; CARBON; CHEMISORPTION; COMPARATIVE EVALUATIONS; DENSITY; ELLIPSOMETRY; ENERGY-LOSS SPECTROSCOPY; FILMS; OXYGEN; PHOTOEMISSION; PLASMA; REFLECTIVITY; REFRACTIVE INDEX; ROUGHNESS; RUTHERFORD BACKSCATTERING SPECTROSCOPY; TEMPERATURE RANGE 0273-0400 K; X RADIATION