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Title: Reaction kinetics during the thermal activation of the silicon surface passivation with atomic layer deposited Al{sub 2}O{sub 3}

The excellent surface passivation of crystalline silicon provided by Al{sub 2}O{sub 3} requires always an activation by a thermal post-deposition treatment. In this work, we present an indirect study of the reaction kinetics during such thermal activation treatments for Al{sub 2}O{sub 3} synthesized by atomic layer deposition. The study was performed for Al{sub 2}O{sub 3} deposited at varying temperatures, which results in different micro-structures of the films and, in particular, different hydrogen concentrations. The effective carrier lifetime was measured sequentially as a function of the annealing time and temperature. From these data, the reaction rate R{sub act} and the activation energy E{sub A} were extracted. The results revealed a rather constant E{sub A} in the range of 1.4 to 1.5‚ÄČeV, independent of the deposition temperature. The reaction rate, however, was found to increase with decreasing deposition temperature, which correlates with an increasing amount of hydrogen being incorporated in the Al{sub 2}O{sub 3} films. This is a strong indication for an interface hydrogenation that takes place during the thermal activation, which is limited by the amount of hydrogen provided by the Al{sub 2}O{sub 3} layer.
Authors:
; ; ;  [1]
  1. Fraunhofer Institute for Solar Energy Systems (ISE), Heidenhofstrasse 2, 79110 Freiburg (Germany)
Publication Date:
OSTI Identifier:
22283146
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 6; Other Information: (c) 2014 AIP Publishing LLC; 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; ANNEALING; CARRIER LIFETIME; CONCENTRATION RATIO; DEPOSITION; HYDROGEN; HYDROGENATION; INTERFACES; LAYERS; MICROSTRUCTURE; PASSIVATION; REACTION KINETICS; SILICON; SURFACES; THIN FILMS