Buried tantalate-niobate microwave varactors
2007 (English)In: 2006 15TH IEEE INTERNATIONAL SYMPOSIUM ON APPLICATIONS OF FERROELECTRICS, 2007, 347-350 p.Conference paper (Refereed)
We present characteristics of microwave variable capacitors (varactors) buried in 2.5 mu m thick AgTa0.5Nb0.5O3 (ATN) film pulsed laser deposited on sapphire single crystal. 2 gm gap interdigital capacitors (IDC) were fabricated by photolithographic, dry etching and lift-off processes. For comparison, similar IDCs were also defined on top of ATN film. Capacitance and loss tangent have been determined using a modified de-embedding technique in the microwave range 25 MHz - 40 GHz. Buried structures show higher values of capacitance and tunability, keeping the same level of losses compared to standard topped devices and resulting in an increased K-factor = tunability/tan delta. Experimental results are explained within equivalent circuit model. Besides the increased performance, the new design avoids the need of a successive planarization step, which could be required in an integration process.
Place, publisher, year, edition, pages
2007. 347-350 p.
, IEEE International Symposium on Applications of Ferroelectrics, ISSN 1099-4734
Silver-tantalate-niobate, voltage tunability, buried interdigital capacitors
Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-6580DOI: 10.1109/ISAF.2006.4387902ISI: 000262360900084ISBN: 978-1-4244-1331-7OAI: oai:DiVA.org:kth-6580DiVA: diva2:11330
15th IEEE International Symposium on Applications of Ferroelectrics Sunset Beach, NC, JUL 30-AUG 03, 2006
QC 201009062006-12-122006-12-122011-04-04Bibliographically approved