Solidly mounted resonator having electromagnetic shielding structure, and manufacturing process

A method for manufacturing a solidly mounted resonator having an electromagnetic shielding structure, comprising:

• S1, fabricating a piezoelectric layer on a first substrate;
• S2, fabricating a lower electrode layer and then an acoustic-wave reflecting layer on the lower electrode layer, and fabricating a first metal shielding wall on a periphery of the lower electrode layer and the acoustic-wave reflecting layer, wherein the first metal shielding wall surrounds an effective region in the lower electrode layer and the acoustic-wave reflecting layer;
• S3, bonding a second substrate onto the acoustic-wave reflecting layer;
• S4, removing the first substrate to expose a back surface of the piezoelectric layer, wherein the back surface faces away from the lower electrode layer;
• S5, etching the piezoelectric layer at a position corresponding to the first metal shielding wall to expose at least a part of the first metal shielding wall;
• S6, fabricating a second metal shielding wall which fills a cavity in the piezoelectric layer and is electrically connected to the first metal shielding wall, wherein the cavity is formed by the etching;
• and
• S7, fabricating an upper electrode layer on the back surface of the piezoelectric layer.