TY - JOUR
T1 - Microwave properties and microstructures of (Ba,Sr)TiO3 thin films on various substrates with annealing temperature
AU - Cho, Kwang Hwan
AU - Kang, Chong Yun
AU - Yoon, Seok Jin
AU - Kim, Hyun Jai
N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.
PY - 2007/7
Y1 - 2007/7
N2 - The dielectric properties of (Ba0.5 Sr0.5)TiO3 ferroelectric thin films have been investigated according to the substrates in order to optimize the their properties. MgO, r-plane sapphire, and poly-crystalline sapphire (Alumina) substrates have been used to deposite (Ba0.5 Sr0.5)TiO3 ferroelectric thin films by RF magnetron sputtering. The BST thin films deposited on the single crystal (100)MgO substrates have high tunability and low dielectric loss. These results are caused by a low misfit between the lattice parameters of the BST films and the substrate. The BST films deposited on r-plane sapphire have relatively high misfit, and the tunability of 17% and dielectric loss of 0.0007. To improve the dielectric properties of the BST films, the post-annealing methods has been introduced. The BST films deposited on (100)MgO, (1102)r-plane sapphire, and poly-crystalline sapphire substrates have best properties in post-annealing conditions of 1050°C, 1100°C, and 1150°C, respectively. The different optimal post-annealing conditions have been found according to the different misfits between the films and substrates, and thermal expansion coefficients. Moreover, the films deposited on alumina substrate which is relatively cheap have a good tunability properties of 23% by the post-annealing.
AB - The dielectric properties of (Ba0.5 Sr0.5)TiO3 ferroelectric thin films have been investigated according to the substrates in order to optimize the their properties. MgO, r-plane sapphire, and poly-crystalline sapphire (Alumina) substrates have been used to deposite (Ba0.5 Sr0.5)TiO3 ferroelectric thin films by RF magnetron sputtering. The BST thin films deposited on the single crystal (100)MgO substrates have high tunability and low dielectric loss. These results are caused by a low misfit between the lattice parameters of the BST films and the substrate. The BST films deposited on r-plane sapphire have relatively high misfit, and the tunability of 17% and dielectric loss of 0.0007. To improve the dielectric properties of the BST films, the post-annealing methods has been introduced. The BST films deposited on (100)MgO, (1102)r-plane sapphire, and poly-crystalline sapphire substrates have best properties in post-annealing conditions of 1050°C, 1100°C, and 1150°C, respectively. The different optimal post-annealing conditions have been found according to the different misfits between the films and substrates, and thermal expansion coefficients. Moreover, the films deposited on alumina substrate which is relatively cheap have a good tunability properties of 23% by the post-annealing.
KW - BST
KW - Ferroelectric
KW - Microwave tunable devices
KW - Thin film
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U2 - 10.3740/MRSK.2007.17.7.386
DO - 10.3740/MRSK.2007.17.7.386
M3 - Article
AN - SCOPUS:34548037253
VL - 17
SP - 386
EP - 389
JO - Korean Journal of Materials Research
JF - Korean Journal of Materials Research
SN - 1225-0562
IS - 7
ER -