Hafnium dioxide capacitors for microwave integrated circuits

Anodized, sputtered hafnium (hafnium dioxide) produces a high-dielectric-constant (∼40) capacitor that has low electric loss. Measurements to 10,5 GHz on capacitors in the range 6 to 96 pF show good performance as dc blocks and bypass capacitors in actual use. Series resistance at 3 GHz is below 0.3 Ω series inductance is of the order of 50 pHy. Temperature effects, processing techniques, and measurements are described. These capacitors are compatible with standard microwave-integrated-circuit processing techniques used to make both lumped and distributed circuits. The results described were obtained on chip versions of these capacitors.