Abstract
In recent years, the high quality factor and high inductance are the main tendency in micro-inductors. In this study, we designed and fabricated RF-inductors and low-frequency inductors, respectively. It is expected to obtain high quality factor and high inductance characteristics. For RF-inductors, we designed and fabricated a suspended double-layer circular spiral inductor on glass substrate by using MEMS technology. Electroplating process and thick photoresist technology were be used to fabricate copper coils. The glass substrate were be used to reduce substrate loss and parallel parasitic effects. The double-layer suspended inductor structure can reduce the capacitive coupling with the substrate effectively and achieve a large inductance per unit area. The S-parameters of RF-inductors were measured in the frequency range from 45 MHz to 20.045 GHz by using hp 8510C vector network analyzer, and then extracted inductance, quality factor and resistance of device by ADS software. It is found that maximum quality factor of 47.7 with an inductance of 3.12 nH and resonance frequency of 15.6 GHz. Compared with other RF-inductors, the performance of quality factor of above suspended double-layer circular spiral inductor is relatively excellent. For low-frequency inductors, Ni80Fe20 alloy is used as the magnetic core material to mantle suspended double-layer circular spiral inductor to reduce loss of magnetic flux. The series inductance and series resistance has been measured using hp 4284A LCR Meter in the frequency range from 10 KHz to 100 KHz. The series inductance value has been achieved 619 nH and 448.55 nH/mm2. Compared with air magnetic core, the use of Ni80Fe20 alloy and closed magnetic path increase inductance value 97.69 times.