Kim, HS Kim, HG Kim, ID Kim, KB Lee, JC 2024-01-21T04:06:20Z 2024-01-21T04:06:20Z 2021-09-02 2005-11-21 0003-6951 https://pubs.kist.re.kr/handle/201004/135981 In this Letter, we report on high-tunability and low-microwave-loss properties of Ba0.6Sr0.4TiO3 (BST) thin films by use of atomic-layer-deposited TiO2 films as the microwave buffer layer between BST and high-resistivity Si substrate. The interdigital capacitor fabricated on BST films grown on TiO2/high resistivity Si (2 k Omega cm) substrates showed the much enhanced tunability value of 33.2% while retaining an appropriate Q factor, as compared to the tunability values of BST (21%) films grown on MgO single-crystal substrates and BST (8.2%) films grown on TiO2/normal Si (10 Omega cm) substrates. The coplanar waveguide BST phase shifter fabricated on TiO2/high resistivity Si exhibited a phase shift of 95 degrees and insertion loss of 3.09 dB at 15 GHz and an applied voltage of 50 V. ALD-grown TiO2 buffer layers enable the successful integration of BST-based microwave tunable devices onto high-resistivity Si wafers. (c) 2005 American Institute of Physics. English AMER INST PHYSICS TA2O5 High-tunability and low-microwave-loss Ba0.6Sr0.4TiO3 thin films grown on high-resistivity Si substrates using TiO2 buffer layers Article 10.1063/1.2133888 1 APPLIED PHYSICS LETTERS, v.87, no.21 APPLIED PHYSICS LETTERS 87 21 scie scopus 000233362300060 2-s2.0-27844580370 Physics, Applied Physics Article TA2O5