Piezoelectric single-crystal element, mems device using same, and method for manufacturing same

A piezoelectric single-crystal element, comprising:

• a wafer;
• a lower electrode stacked on the wafer;
• a piezoelectric single-crystal thin film stacked on the lower electrode;
• and
• an upper electrode stacked on the piezoelectric single-crystal thin film,
• wherein the piezoelectric single-crystal thin film is composed of PMN-PT, PIN-PMN-PT or Mn:PIN-PMN-PT, and
• the piezoelectric single-crystal thin film has a polarization direction set to a <001> axis, a <011> axis or a <111> axis,
• wherein the upper electrode includes an operation-part-side upper terminal portion,
• the lower electrode includes an operation-part-side lower terminal portion,
• the piezoelectric single-crystal thin film has an operation part formation hole formed over the periphery of a central portion,
• the element further comprises a vibrable operation part defined as a central portion surrounded by the operation-part-side upper terminal portion, the operation-part-side lower terminal portion, and the operation part formation hole of the piezoelectric single-crystal thin film, and
• a lower operation space is formed below the operation part on the wafer to define the operation performance of the operation part.