Abstract
In this letter, we report on increased tunability of Ba 0.6Sr 0.4TiO 3 (BST) thin films by use of Ta 2O 5 and TiO 2 films as buffer layers between BST and Si substrates. Ta 2O 5 and TiO 2 buffer layers were grown by atomic layer deposition (ALD) onto Si substrates followed by pulsed laser deposition of Ba 0.6Sr 0.4TiO 3 thin films onto the buffer layers. The randomly oriented BST films deposited on TiO 2/Si substrates exhibited a broader grain size distribution than the (110) textured BST films grown on Ta 2O 5/Si substrates. At an applied voltage of 10 V, the BST films grown on Ta 2O 5/Si and TiO 2/Si substrates showed much enhanced tunability values of 53.1% and 72.9%, respectively, as compared to the 20.7% value obtained with BST films grown on MgO single crystal substrates. Successful integration of BST low voltage microwave tunable devices onto Si substrates thus appears possible with the aid of ALD grown Ta 2O 5 or TiO 2 buffer layers.
Original language | English |
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Pages (from-to) | 4705-4707 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 85 |
Issue number | 20 |
DOIs | |
State | Published - 15 Nov 2004 |