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Title: Thermodynamic assessment and experimental verification of reactive ion etching of magnetic metal elements

A thermodynamic analysis of etch chemistries for Co, Fe, and Ni using a combination of hydrogen, oxygen, and halogen gases suggested that a single etchant does not work at 300 K; however, a sequential exposure to multiple etchants results in sufficiently high partial pressure of the reaction products for the process to be considered viable. This sequential dose utilized the two reactions, a surface halogenation followed by the secondary etchant exposure. (MX{sub 2} (c) + 3Y →MY(g) + 2XY(g), where M = Co, Fe, Ni; X = F, Cl, Br; Y = O, H) The volatilization reaction induced by sequential plasma exposure changed the equilibrium point, increasing the partial pressure of the etch product. Amongst all combinations, Cl{sub 2} or Br{sub 2} plasmas followed by H{sub 2} plasma were the most effective. From both the gas phase diagnostics and surface composition analysis, H{sub 2} plasma alone could not etch metallic Co, Fe, and Ni films but alternating doses of Cl{sub 2} and H{sub 2} plasmas resulted in more effective removal of chlorinated metals and increased the overall etch rate.
Authors:
; ;  [1]
  1. Chemical and Biomolecular Engineering, UCLA, Los Angeles, California 90095 (United States)
Publication Date:
OSTI Identifier:
22318049
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Vacuum Science and Technology. A, Vacuum, Surfaces and Films; Journal Volume: 32; Journal Issue: 4; Other Information: (c) 2014 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; BROMINE; CHLORINE; ETCHING; HALOGENATION; HYDROGEN; METALS; OXYGEN; PARTIAL PRESSURE; PLASMA; THERMODYNAMICS