Abstract: An improved apparatus and method for the analysis of surface data collected using a sub-micron scale metrology instrument which provides a persistent user experience by allocating set portions of the display to major functional regions thereby allowing a quick to learn and easy to user interface for the setup, analysis, and display of microscopic 3D surface data measurements and resulting analytic data with a variety of 3D surface scanners.

Abstract: An interferometric profiler is used to measure object motion by modifying the motion of the scanner so that the phase variation at each scanning step is kept within the acceptable limits of the algorithm used to calculate phase changes. The scanner motion is so manipulated on the basis of prior knowledge about the nature of the object motion, or knowledge obtained by pre-calibration, or by real-time feedback based on current measurements. The object motion is recovered from the scanning information by subtracting the scanner position from the object position as it evolves during the scan.

Abstract: Two threshold parameters are used to identify the intensity modulation peaks corresponding to the interfaces of the two sides of a thin film with the adjacent media. The first parameter is used to distinguish modulation data from noise and is set on the basis of actual background noise data measured during the interferometric scan. The second parameter is used to separate actual contrast data from signals of relatively high modulation that satisfy the first parameter but do not in fact result from interference fringes. Data that satisfy both parameters are considered valid modulation data and the peak of each modulation envelope is then calculated using conventional means. The thickness of the film at each pixel is obtained by dividing the scanning distance corresponding to the two peaks by the group index of refraction of the film material.

Abstract: Average fringe contrast is determined by PSI measurements at each step of relatively large translations of the reference optics and mirror of a white-light Linnik interference objective and the resulting data are used to minimize the OPD between the reference and test beam paths of the instrument. Utilizing the same algorithms used in the art to perform conventional vertical scanning interferometry, the position of minimum OPD is determined by finding the position of maximum average fringe contrast. Furthermore, by automating the system with a precise translation mechanism, operator-to-operator variations are completely eliminated and the precision of the process of OPD minimization is greatly improved. In another embodiment of the invention, the optimal focal position of the reference mirror is found at the same time by calculating the average lateral variation of fringe contrast as a function of OPD and focal position.

Abstract: A method of operation of a scanning mechanism that produces multiple constant-speed translations within the scanning range of operation. According to one aspect of the invention, when the instrument translates over a region where useful fringes are substantially absent, such as over the steep portion of a step discontinuity, the scanner is quickly accelerated to a higher constant speed and collection of intensity data is stopped until it reaches a new region of observable fringes. The scanner then is quickly decelerated to a slower constant speed and acquisition of intensity data resumes. According to another aspect of the invention, the position of the scanner during the nonlinear transition between regions of different constant speeds is determined by applying a transition factor based on the rate of acceleration (or deceleration) during the transition period.