Air-Gap Transmission Lines on Organic Substrates for Low-Loss Interconnects

• Published in: IEEE transactions on microwave theory and techniques Vol. 55; no. 9; pp. 1919 - 1925
• Main Authors: Spencer, T.J., Joseph, P.J., Tae Hong Kim, Swaminathan, M., Kohl, P.A.
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.09.2007; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Air gaps; Applied sciences; Capacitance measurement; Channels; Circuit properties; Design. Technologies. Operation analysis. Testing; Dielectric constant; Dielectric loss measurement; dielectric losses; Dielectric measurements; Dielectric substrates; Dielectrics; Electric, optical and optoelectronic circuits; Electronics; Exact sciences and technology; Fabrication; Frequency; High frequencies; Integrated circuit interconnections; Integrated circuits; Integrated circuits by function (including memories and processors); Low frequencies; Microwave circuits, microwave integrated circuits, microwave transmission lines, submillimeter wave circuits; Microwaves; multiprocessor interconnection; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Tangents; Transmission line measurements; Transmission lines; Dielectric loss; Parameter estimation; Air gaps; multiprocessor interconnection; Low frequency; transmission lines; Multiprocessor; Microwave integrated circuits; Effective dielectric constant; Transmission line; Interconnection; s parameter; Integrated circuit; Air gap; Capacitance; dielectric losses; Monolithic integrated circuit; High frequency
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2007.904326

The fabrication of low-loss transmission line structures with an air dielectric layer is described. The channels are characterized at low frequency (10 and 100 kHz) using capacitance and loss tangent and at high frequency (500 MHz to 10 GHz) using -parameter measurements. The incorporation of an air gap resulted in structures with effective dielectric constants between 1.5-1.8 and significantly lower loss tangents. The fabrication technique could be used to create more complicated air gap transmission line structures for use in monolithic microwave integrated circuits.