Patent ID: 7490390

Claim:
A method of manufacturing a voltage controlled oscillator in which a thin film Bulk Acoustic Wave (BAW) resonator and a variable capacitor element are formed on a first substrate, comprising: forming the thin film BAW resonator which includes: forming an insulating film on the first substrate; forming a lower electrode layer, which is positioned to face the first substrate, on the insulating film; forming a first piezoelectric film on the lower electrode layer; forming an upper electrode layer on the first piezoelectric film; and selectively patterning the lower electrode layer, the first piezoelectric film and the upper electrode layer such that the insulating film is patterned in a manner to form a first support section, thereby forming one laminate structure of the lower electrode, the first piezoelectric film, and the upper electrode, which is supported on the first support section with one gap formed between the first substrate and the laminate structure; and forming the variable capacitor element, which includes: forming a stationary electrode on the first substrate; covering the stationary electrode with a dielectric film; forming another insulating film on the first substrate section; forming a first electrode on the another insulating film; forming a second piezoelectric film on the first electrode; forming a second electrode on the second piezoelectric film; selectively patterning the first electrode, the second piezoelectric film and the second electrode so as to form an actuator of another laminate structure of the first electrode, the second piezoelectric film, and the second electrode and to form a movable electrode positioned to face the stationary electrode and mechanically coupled to and supported on the actuator; and selectively patterning the another insulating film so as to form another gap between the movable electrode and the stationary electrode and to form a second support section for supporting the actuator.