Tunable (Ba, Sr)TiO3 interdigital capacitor onto Si wafer for reconfigurable radio

✍ Scribed by Ki-Byoung Kim; Tae-Soon Yun; Jong-Chul Lee; Mohamed Chaker; Ke Wu

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 536 KB
• Volume: 49
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.22657

✦ Synopsis

Abstract

In this article, the potential feasibility of integrating BST films into Si wafer by adopting tunable interdigital capacitor (IDC) with TiO~2~ thin film buffer layer is suggested. TiO~2~ as buffer layer is grown onto Si substrate by atomic layer deposition and the coplanar IDC on Ba~x~Sr~1−x~TiO~3~(500 nm)/TiO~2~(50 nm)/high resistivity Si (HR‐Si) is fabricated. BST interdigital tunable capacitors integrated on HR‐Si substrate with high tunability and low loss tangent are characterized for their microwave performances. BST/HR‐Si and BST/TiO~2~/HR‐Si IDCs show much enhanced tunability values of 31% and 40%, respectively as compared to the value of 21% obtained with BST film on MgO single crystal substrate at the bias of 5 kV/cm. BST/TiO~2~/HR‐Si structure shows much improved figure of merit of 504.4 as compared to 418.53 and 101.68 of BST/MgO and BST/HR‐Si structure, respectively. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2144–2148, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.22657