NOVEL IMAGING METHOD IN SCANNING ACOUSTIC MICROSCOPY FOR THIN-FILMS

A novel virtual cavity scanning acoustic microscope (VSAM), in which a resonating acoustic cavity is formed by a PZT plate mirror and an aco ustic lens, has been developed. Resonance conditions were obtained by placing a PZT mirror in the focal plane of the acoustic lens and air b ubble samples were examined. Practical geometry conditions and express ions for the acoustic resonance quality factor and loss, are given. Th is resonance phenomenon is used for high amplification of small acoust ic signals and for the signature identification of surface and subsurf ace soft features in acoustic microscopy. A dedicated 3D image process ing software has been used to extract detailed images of the scanned o bjects in resonance.