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

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 Al2O3 growth via sequential self-limiting surface reaction of trimethylaluminum (TMA) and H2O is clearly resolved. Calibration enables quantitation of the exothermic TMA and H2O half-reactions with high precision, -343 kJ/mol TMA and -251 kJ/mol H2O, 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 precursors 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 TiO2 and MnO.
Authors:
 [1] ;  [2] ; ORCiD logo [3] ;  [4] ; ORCiD logo [4]
  1. Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States
  2. Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
  3. Department of Chemical Engineering, University of Washington, Seattle, Washington 98195, United States; Department of Chemistry, University of Washington, Seattle, Washington 98195, United States
  4. Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States
Publication Date:
Grant/Contract Number:
AC02-06CH11357; 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:
Argonne National Lab. (ANL), Argonne, IL (United States); 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: 1411036; OSTI ID: 1414910

Lownsbury, James M., Gladden, James A., Campbell, Charles T., Kim, In Soo, and Martinson, Alex B. F.. Direct Measurements of Half-Cycle Reaction Heats during Atomic Layer Deposition by Calorimetry. United States: N. p., Web. doi:10.1021/acs.chemmater.7b01491.
Lownsbury, James M., Gladden, James A., Campbell, Charles T., Kim, In Soo, & Martinson, Alex B. F.. Direct Measurements of Half-Cycle Reaction Heats during Atomic Layer Deposition by Calorimetry. United States. doi:10.1021/acs.chemmater.7b01491.
Lownsbury, James M., Gladden, James A., Campbell, Charles T., Kim, In Soo, and Martinson, Alex B. F.. 2017. "Direct Measurements of Half-Cycle Reaction Heats during Atomic Layer Deposition by Calorimetry". United States. doi:10.1021/acs.chemmater.7b01491.
@article{osti_1398132,
title = {Direct Measurements of Half-Cycle Reaction Heats during Atomic Layer Deposition by Calorimetry},
author = {Lownsbury, James M. and Gladden, James A. and Campbell, Charles T. and Kim, In Soo and Martinson, Alex B. F.},
abstractNote = {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 Al2O3 growth via sequential self-limiting surface reaction of trimethylaluminum (TMA) and H2O is clearly resolved. Calibration enables quantitation of the exothermic TMA and H2O half-reactions with high precision, -343 kJ/mol TMA and -251 kJ/mol H2O, 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 precursors 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 TiO2 and MnO.},
doi = {10.1021/acs.chemmater.7b01491},
journal = {Chemistry of Materials},
number = 20,
volume = 29,
place = {United States},
year = {2017},
month = {10}
}