Evaluation of acoustic wave velocities in piezoelectric, dielectric and intrinsic semiconductor materials using thermal wave propagation

In the development of various SAW devices, it is very important to evaluate some qualities of materials before we start any fabrication process of the devices. Last year, we proposed a new non-destructive method to evaluate the acoustic wave velocity by thermal measurement and evaluated the acoustic wave velocity in a thin diamond film grown on Si. We extended this technique to other materials such as intrinsic Si and yz lithium niobate wafers and re-examined the approximations used in the previous report. We could evaluate the acoustic wave velocities in these materials within about 10% error of the known values measured by other accurate methods. Thus, we could demonstrate the feasibility of this simple technique again for quick evaluation of the materials. The detail of the experimental results, the evaluation processes and related problems are discussed