Change of electrical properties of rutile- and anatase-TiO2 films by atomic layer deposited Al2O3

Toshihide Nabatame, Ippei Yamamoto, Tomomi Sawada, Akihiko Ohi, Thang Duy Dao, Tomoji Ohishi, Tadaaki Nagao

Research output: Chapter in Book/Report/Conference proceedingConference contribution


The electrical characteristics of rutile- and anatase-type TiO2 films were investigated by supplying alternatively pulses of trimethylaluminum (TMA) and H2O vapours after AI2O3 deposition using atomic layer deposition (ALD). As-grown rutile- and anatase-TiO2 films had an insulative property of ∼105ωcm, but its resistivity dropped dramatically to 10-1-10-2 ωcm and stayed low after supplying 5 cycles for ALD of AI2O3. The carrier density values of both TiO2 films were 1019-1020 cm-3 in the low-resistivity region. The Hall mobility values were 0.5-15 cm2V-1s-1, which correspond well with the literature values of 0.2-6 and 10 cm2V-1s-1 for thin-film and single-crystal anatase-TiO2, respectively. We propose one mechanism that oxygen vacancies must be formed by the reaction of adsorbed TMA precursor and the oxygen in TiO2 film after ALD-AI2O3 deposition and leads to electron generation, and results in change of resistivity from an insulative into a semiconductor characteristic.

Original languageEnglish
Title of host publicationAtomic Layer Deposition Applications 15
EditorsFred Roozeboom, Stefan De Gendt, Jolien Dendooven, Jeffrey W. Elam, Oscar van der Straten, Chanyuan Liu, Ganesh Sundaram, Andrea Illiberi
PublisherElectrochemical Society Inc.
Number of pages7
ISBN (Print)9781607688778
Publication statusPublished - 2019
EventInternational Symposium on Atomic Layer Deposition Applications 15 - 236th ECS Meeting - Atlanta, United States
Duration: 2019 Oct 132019 Oct 17

Publication series

NameECS Transactions
ISSN (Print)1938-6737
ISSN (Electronic)1938-5862


ConferenceInternational Symposium on Atomic Layer Deposition Applications 15 - 236th ECS Meeting
Country/TerritoryUnited States

ASJC Scopus subject areas

  • Engineering(all)


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