Thickness Measurement of Ni Thin Film Using Dispersion Characteristics of a Surface Acoustic Wave

Abstract In this study, we suggest a method to measure the thickness of thin films nondestructively using the dispersion characteristics of a surface acoustic wave propagating along the thin film surface. To measure the thickness of thin films, we deposited thin films with different thicknesses on a Si (100) wafer substrate by controlling the deposit time using the E-beam evaporation method. The thickness of the thin films was measured using a scanning electron microscope. Subsequently, the surface wave velocity of the thin films with different thicknesses was measured using the V(z) curve method of scanning acoustic microscopy. The correlation between the measured thickness and surface acoustic wave velocity was verified. The wave velocity of the film decreased as the film thickness increased. Therefore, thin film thickness can be determined by measuring the dispersion characteristics of the surface acoustic wave velocity. Keywords: Scanning Acoustic Microscopy, V(z) Curve, Dispersion, Surface Wave Velocity, Thin Film Thickness[접수일: 2014. 3. 31, 수정일: 2014. 4. 17, 게재확정일: 2014. 4. 17] *한양대학교, **서울과학기술대학교, ***한국표준과학연구원 ✝Corresponding Author: Department of Mechanical and Automotive Engineering, Seoul National University of Science and Technology, Seoul 139-743, Korea (E-mail: ikpark@seoultech.ac.kr)