Step-height and step-transition measurements with the heterodyne differential interferometer

ABSTRACT The express method of determination of microstep parameters (height and width) based on the comparisonof the complex simulated responses with the experimental one has been elaborated. A superresolution indetermination of object lateral parameters is obtained with using a priori information. Keywords: heterodyne microscopy, interferometry, optical superresolution, laser metrology1. INTRODUCTION Restoration of the microobject profile on apparatus response is the actual problem of modern microscopy,especially of heterodyne microscopy [1, 2]. The advantages of heterodyne microscopy are not only its highsensitivity to object relief but also the possibility of simultaneous determination of amplitude and phasecomponents of the complex response. This peculiarity enlarges the opportunity of the response processing [3, 4] . The heterodyne differential interferometer (HDI) with the common path scheme [5, 6] possesses high immunity to acoustic noise. The processing of the differential response for this type of HDI is more complicatedthan nondifferential response processing but previously developed solution algorithm of direct optical problem