Title :
Integration of coplanar (Ba,Sr)TiO/sub 3/ microwave phase shifters onto Si wafers TiO/sub 2/ buffer layers
Author :
Kim, Ki Byoung ; Yun, Tae Soon ; Lee, Jong Chul ; Kim, Hyun Suk ; Kim, Ho Gi ; Kim, Il Doo
Author_Institution :
RFIC Res. & Educ. Center, Kwangwoon Univ., Seoul, South Korea
fDate :
3/1/2006 12:00:00 AM
Abstract :
In this paper, a Ba/sub 0.6/Sr/sub 0.4/TiO/sub 3/ (BST) tunable phase shifter with TiO/sub 2/ films as microwave buffer layer between BST and silicon (Si) substrates is presented. The TiO/sub 2/ buffer layer is grown by atomic layer deposition (ALD) onto Si substrate followed by pulsed laser deposition (PLD) of BST thin films onto the TiO/sub 2/ buffer layer. The phase shifter fabricated on BST films grown on TiO/sub 2//Si substrate shows a good figure of merit (FOM) of 75.4/spl deg//dB by exhibiting improved tunability while retaining an appropriate dielectric Q as compared to 55.1/spl deg//dB of BST/MgO structure. The TiO/sub 2/ buffer layer grown by ALD enables successful integration of BST-based microwave tunable devices with high resistive Si wafer.
Keywords :
atomic layer deposition; barium compounds; buffer layers; dielectric thin films; microwave materials; microwave phase shifters; pulsed laser deposition; strontium compounds; titanium compounds; ALD; BST thin films; PLD; atomic layer deposition; coplanar microwave phase shifters; dielectric Q; microwave buffer layer; pulsed laser deposition; tunable phase shifter; wafers; Binary search trees; Buffer layers; Dielectric substrates; Dielectric thin films; Phase shifters; Pulsed laser deposition; Semiconductor films; Silicon; Strontium; Tunable circuits and devices;
Journal_Title :
Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on
DOI :
10.1109/TUFFC.2006.1610559
