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Excellent silicon surface passivation with 5 Å thin ALD Al 2 O 3 layers: Influence of different thermal post‐deposition treatments
Author(s) -
Richter Armin,
Benick Jan,
Hermle Martin,
Glunz Stefan W.
Publication year - 2011
Publication title -
physica status solidi (rrl) – rapid research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.786
H-Index - 68
eISSN - 1862-6270
pISSN - 1862-6254
DOI - 10.1002/pssr.201105188
Subject(s) - passivation , atomic layer deposition , annealing (glass) , silicon , materials science , boron , common emitter , deposition (geology) , analytical chemistry (journal) , saturation current , thin film , layer (electronics) , chemical engineering , nanotechnology , chemistry , optoelectronics , metallurgy , electrical engineering , paleontology , organic chemistry , engineering , chromatography , sediment , biology , voltage
Thin layers of Al 2 O 3 always require a thermal post‐deposition treatment to activate the passivation on crystalline silicon surfaces. In this work, we studied the influence of different thermal post‐deposition treatments for the activation of passivating ALD Al 2 O 3 single layers and Al 2 O 3 /SiN x stacks. For the stacks, especially with less than 5 nm Al 2 O 3 , a short high temperature process at ∼800 °C results in a remarkably lower surface recombination compared to a commonly applied annealing at 425 °C. We observed that four ALD cycles of Al 2 O 3 are sufficient to reach the full potential of surface passivation, and even with one atomic layer of Al 2 O 3 (one ALD cycle) emitter saturation current densities as low as 45 fA/cm 2 can be reached on boron‐diffused emitters. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)