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Title: Direct Measurements of Half-Cycle Reaction Heats during Atomic Layer Deposition by Calorimetry

Here, we introduce a new high-temperature adsorption calorimeter that approaches the ideal limit of a heat detector whereby the signal at any time is proportional to the heat power being delivered to the sample and prove its sensitivity for measuring pulse-to-pulse heats of half-reactions during atomic layer deposition (ALD) at 400 K. The heat dynamics of amorphous Al 2O 3 growth via sequential self-limiting surface reaction of trimethylaluminum (TMA) and H 2O is clearly resolved. Calibration enables quantitation of the exothermic TMA and H 2O half-reactions with high precision, -343 kJ/mol TMA and -251 kJ/mol H 2O, respectively. A time resolution better than 1 ms is demonstrated, allowing for the deconvolution of at least two distinct surface reactions during TMA microdosing. It is further demonstrated that this method can provide the heat of reaction versus extent of reaction during each precursor’s half-reaction, thus providing even richer mechanistic information on the surface processes involved. The broad applicability of this novel calorimeter is demonstrated through excellent signal-to-noise ratios of less exothermic ALD half-reactions to produce TiO 2 and MnO.
Authors:
 [1] ;  [1] ; ORCiD logo [1] ;  [2] ; ORCiD logo [2]
  1. Univ. of Washington, Seattle, WA (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
SC0012702
Type:
Published Article
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Volume: 29; Journal Issue: 20; Journal ID: ISSN 0897-4756
Publisher:
American Chemical Society (ACS)
Research Org:
Regents of the Univ. of Minnesota, Minneapolis, MN (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
OSTI Identifier:
1398132
Alternate Identifier(s):
OSTI ID: 1414910