Microwave Inductors on Silicon Substrates

Microwave inductive structures are fabricated on high resistivity (3 k to 7 k ¿-cm, measured) Si, GaAs, and quartz substrates under two conditions: metal-substrate and metal-insulator-substrate. The insulators are sandwiches of: SiO2(field)/Si3N4 and SiO2(field)/Si3N4 with SiO2(gate). The measured unloaded Q of single layer spirals and meander inductors on Si substrates are comparable to the measured unloaded Q of the same structures realized on GaAs and quartz substrates. These results are in agreement with the ones obtained using coplanar transmission lines (CPW´s), which further confirm that high resistivity Si can be used as a microwave substrate.