Tunable barium strontium titanate thin film capacitors for RF and microwave applications

• Published in: IEEE microwave and wireless components letters Vol. 12; no. 1; pp. 3 - 5
• Main Authors: Tombak, A., Maria, J.-P., Ayguavives, F., Zhang Jin, Stauf, G.T., Kingon, A.I., Mortazawi, A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.01.2002; Institute of Electrical and Electronics Engineers
• Subjects: Applied sciences; Barium; Barium strontium titanates; Binary search trees; Capacitance; Capacitors; Circuit properties; Devices; Dielectric loss; Dielectric losses; Dielectric measurements; Diodes; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; Radio frequencies; Radio frequency; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Strontium; Thin films; Titanium compounds; Transistors; Varactors; Performance evaluation; Dielectric loss; Barium titanate; Q factor; Large signal behavior; Microwave; Radiofrequency; Voltage control; Modeling; Thin film capacitor; Quaternary compound; Varactor diode; Strontium titanates
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/7260.975716

The measurement results for thin film barium strontium titanate (BST) based voltage tunable capacitors intended for RF applications are reported. At 9 V DC, BST capacitors fabricated using MOCVD (metalorganic chemical vapor deposition) method achieved 71% (3.4:1) tunability. The measured device quality factor (Q) for BST varactors is comparable with the device Q for commercially available varactor diodes of similar capacitance. The typical dielectric loss tangent was in the range 0.003-0.009 at VHF. Large signal measurement and modeling results for BST thin film capacitors are also presented.