Michelson microscope interference objective for micro-structure topography measuring

Abstract

Nowadays, the trends of miniaturization of sensors and inspection devices have been of major importance in science and technology. The characterization of microchips, integrated circuits, MEMS, and micro-sensors is important to determine their proper operation. Due to their element small size may have structural fails for improper handling of them. This paper proposes the use of a Michelson interferometric objective for the determination of topographical features in materials at micro and nanoscale level. The main advantage of this method is its non-invasive nature that allows testing in soft materials without damage. The Michelson interferometric microscope objective with a magnification of 5X illuminated with a 632nm He-Ne laser is used. Fringes that allow the study of the topography of these structures are properly analyzed. The acquisition of the interferograms was performed by a CCD, which are handled by the method of phase-stepping. An integrated circuit of a CCD as target is used. A reconstruction of the microscopic topography of the sample produced results with a statistical error in the topography of 12nm. Application of this method is to conduct quality control tests in manufacture of electronic components such as micro-chips and integrated circuits.

Phase-shifting interference microscope with extendable field of measurement

“…The configurations of IMs are based on the theory of optical interferometry, which can be classified as follows: Michelson [19][20][21], Mirau [22][23][24], and Linnik [21,25]. When using IMs, the sample is normally illuminated and the phase-shifting technique is used to retrieve the contours.…”