METHOD FOR MEASURING PIEZOELECTRIC COEFFICIENT OF PIEZOELECTRIC THIN FILMS BY STRAIN-MONITERING PNEUMATIC LOADING METHOD AND APPARATUS THEREFOR

摘要

PURPOSE: A method of measuring the piezoelectric coefficient of a piezoelectric thin film by using an SMPLM(Strain-Monitoring Pneumatic Loading Method) and a measuring apparatus thereof are provided to be capable of simply and exactly measuring piezoelectricity constant without using a complicated equipment. CONSTITUTION: After preparing a substrate/sample coupled body, the substrate/sample coupled body is located at the center portion of a chamber(10). At this time, the substrate/sample coupled body includes a substrate(12), the first electrode(16) formed on the upper surface of the substrate, a piezoelectric sample(14) formed at the upper portion of the resultant structure, and the second electrode(17) formed on the sample. Then, a strain gauge(18) is attached on the lower surface of the substrate. Pressure variation is measured while vertically applying pressure to the surface of the sample by supplying gas into the chamber. After measuring the electric charge variation of the sample according to the pressure variation of the two electrode, the strain variation of the sample surface is measured according to the pressure variation of the strain gauge. Then, piezoelectric constant is obtained by using the measured values.