| 摘要 |
PURPOSE:To measure the thickness in a sample in submicrons, by measuring the degree of attenuation in reflected wave, which is leaked and yielded from an elastic surface wave, which is propagated on the surface of the sample. CONSTITUTION:The ultrasonic wave generated by a piezoelectric transducer 2 is converged and projected on a sample 5 through a liquid coupler 4, which is filled between an acoustic lens 3 and the sample 5. The reflected wave from the sample 5 is returned to the piezoelectric transducer 2 and converted into an electric signal proportional to the amplitude of the reflected wave. The signal is sent to a receiver 8 through a circulator 1. The signal, which is sent to the receiver 8, is imparted to a gate circuit 9, where only the desired leaked elastic surface wave is extracted and sent to a computer 13 through a peak detector 10, an A/D converter 11, and an interface 12. The thickness of the sample 5 is computer by the computer 13. |
