| 摘要 |
PROBLEM TO BE SOLVED: To measure the propagation velocity of leakage surface acoustic waves(LSAW) efficiently by correcting the changes in the propagation characteristics of LSAW due to the effects of reflected waves from the backside of a sample through the use of a conversion curve created from frequency characteristics. SOLUTION: The changes in the measured LSAW velocity due to the effects of back surface reflected waves at each point of measurement are estimated from the corresponding relation ship between a conversion curve created on the basis of the frequency characteristics of LSAW velocity at one certain point on a sample surface and the finite difference between measured values at two frequencies at another point of measurement to correct measured values. In the case of correcting the measured value of LSAW velocity on a sample A with thickness distribution in the shape of, for example, a recessed surface, a point of measurement P0 on a sample surface of a thickness h0 is selected, and the frequency characteristics of LSAW at the point are measured. Frequency characteristics VVSAW (f, h0 ) such as a curve B due to the effects of backside reflected waves are obtained. By taking a moving average at a period ΔF on it, the true value VLSAW of LSAW velocity at the point of measurement P0 is found. |
