TY - GEN
T1 - Change of electrical properties of rutile- and anatase-TiO2 films by atomic layer deposited Al2O3
AU - Nabatame, Toshihide
AU - Yamamoto, Ippei
AU - Sawada, Tomomi
AU - Ohi, Akihiko
AU - Dao, Thang Duy
AU - Ohishi, Tomoji
AU - Nagao, Tadaaki
N1 - Funding Information:
This study was supported by the World Premier International Research Center Initiative (WPI) and the Ministry of Education, Culture, Sports, Science and Technology (MEXT) of Japan, and partly supported by the CREST "Phase Interface Science for Highly Efficient Energy Utilization" (JPMJCR13C3), Japan Science and Technology Agency (JST). The authors thank all staff members of the Nanofabrication group of the National Institute for Materials Science (N1MS) for their support.
Publisher Copyright:
© The Electrochemical Society.
PY - 2019
Y1 - 2019
N2 - 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.
AB - 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.
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U2 - 10.1149/09203.0015ecst
DO - 10.1149/09203.0015ecst
M3 - Conference contribution
AN - SCOPUS:85077217572
SN - 9781607688778
T3 - ECS Transactions
SP - 15
EP - 21
BT - Atomic Layer Deposition Applications 15
A2 - Roozeboom, Fred
A2 - De Gendt, Stefan
A2 - Dendooven, Jolien
A2 - Elam, Jeffrey W.
A2 - van der Straten, Oscar
A2 - Liu, Chanyuan
A2 - Sundaram, Ganesh
A2 - Illiberi, Andrea
PB - Electrochemical Society Inc.
T2 - International Symposium on Atomic Layer Deposition Applications 15 - 236th ECS Meeting
Y2 - 13 October 2019 through 17 October 2019
ER -