PIEZOELECTRIC RESONATOR, PIEZOELECTRIC OSCILLATOR USING THIS AND METHOD FOR MANUFACTURING PIEZOELECTRIC RESONATOR

摘要

PROBLEM TO BE SOLVED: To provide a piezoelectric resonator which has a smooth end face at a floating structure part becoming the oscillation part of an acoustic wave and obtains excellent frequency characteristic even in a high frequency area. SOLUTION: In the piezoelectric resonator provided with a silicon substrate where a through hole is bored, a boron doped layer consisting of silicon, doped with boron and supported by the silicon substrate so as to cover the through hole, an insulator layer arranged on the boron doped layer and a piezoelectric body layer where an upper electrode and a lower electrode consisting of film- like conductor provided on the insulator are formed on a front surface and a rear surface, the boron doped layer is thinner than the insulator layer.