Methods and systems for mapping surface topography of semiconductor substrates

Abstract

Methods and systems for high throughput and high resolution measurement of surface topography of substrates employed in semiconductor device manufacturing are described herein. A beam steering device scans an illumination beam along a beam scan path incident on a substrate surface. In addition, a specimen positioning system moves the substrate with respect to the illumination beam. In some embodiments, a hypercentric focusing lens in the illumination beam path between the beam steering device and the substrate eliminates the need for an optical element in the optical path between the surface under measurement and a position sensitive detector in the optical path of the reflected beam. A computing system generates a map of wafer tilt based on the detected position of the reflected beam at the detector. In a further aspect, a high resolution surface height map is generated based on the measured surface tilt map.

Images