Patent ID: 7022540

Claim:
A fabrication method of a cantilever sensor, comprising: depositing a silicon nitride film respectively onto the top and the bottom surfaces of a silicon substrate; depositing a silicon oxide film onto the top silicon nitride film; depositing a lower electrode onto the silicon oxide film; depositing a first piezoelectric film and a second piezoelectric film onto the lower electrode so as not to contact with each other; depositing an upper electrode respectively onto the first and second piezoelectric films; depositing a protecting film onto the silicon oxide film, the lower electrode, the first and second piezoelectric films and the upper electrodes; forming a first opening on the protecting film of the upper electrode and forming a second opening on the protecting film of the lower electrode; forming a first and second contact pads respectively on the first and second openings; removing part of the silicon nitride film on the bottom surface of the substrate; forming a membrane of predetermined thickness by etching the silicon substrate in which the silicon nitride film is removed; and forming a cantilever by removing part of the membrane by etching the surrounding portion of the cantilever.