On-Wafer Measurement Errors Due to Unwanted Radiations on High-Q Inductors

• Published in: IEEE transactions on microwave theory and techniques Vol. 64; no. 9; pp. 2905 - 2911
• Main Authors: Bushueva, Olga, Viallon, Christophe, Ghannam, Ayad, Parra, Thierry
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Computer simulation; Devices; Electronics; Engineering Sciences; Fixtures; High-Q inductor; high-resistivity substrate; Inductors; Mathematical models; Microwaves; on-wafer measurements; Probes; Q-factor; quality factor; radiation; Radio frequency; RF probe; Simulation; Solenoids; Solid modeling; Spirals; RF probe; high-Q inductor; radiation; On-wafer measurements; high-resistivity substrate; quality factor
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2016.2588486

This paper investigates the disagreements that may occur between on-wafer measurements and electromagnetic (EM) simulations of high-Q inductive devices. Such disagreements are highlighted on a planar spiral inductor and a 3-D solenoid which exhibit measured maximum Q-factors of 27 and 35, respectively, while 42 and 45 were expected from EM simulations. Both devices are fabricated on high-resistivity substrates. A radiative interaction is identified between RF probe and inductive device under test. By using EM simulations, extra-losses associated with this parasitic effect are fully modeled through the calculation of radiation and dissipation related Q-factors. Adjustments of on-wafer probe setup are proposed to reduce this parasitic effect. Finally, the 3-D solenoid inductor is characterized using a new experimental fixture, and the maximum Q of 45 predicted by EM simulation is retrieved.