INTERFERENCE MEASURING APPARATUS AND INTERFERENCE MEASURING METHOD

摘要

An interference measuring apparatus measuring a distance to a surface for inspection is provided. The interference measuring apparatus includes a light dividing unit that divides each of the plurality of light fluxes into light to be inspected and reference light; an objective lens that transmits light to be inspected; a photoelectric conversion element that receives interference light between the light to be inspected and the reference light for each of the plurality of light fluxes and output an interference signal obtained by converting the interference light into an electrical signal; and a calculation unit that calculates the distance to the surface to be inspected based on a phase obtained by subtracting a defocused wavefront from a phase component of a complex amplitude at the pupil position of the objective lens which transmitted light to be inspected for each of the plurality of light fluxes by using the interference signal.

主权项

1. An interference measuring apparatus that measures a distance to a surface to be inspected using a plurality of light fluxes whose wavelengths are different from each other, the interference measuring apparatus comprising:
a light dividing unit configured to divide each of the plurality of light fluxes into light to be inspected and reference light; an objective lens configured so that the light to be inspected is transmitted through said objective lens; a photoelectric conversion element configured to receive interference light between the light to be inspected and the reference light for each of the plurality of light fluxes and output an interference signal obtained by converting the interference light into an electrical signal; and a calculation unit configured to calculate the distance to the surface to be inspected based on a phase obtained by subtracting a defocused wavefront from a phase component of a complex amplitude at the pupil position of the objective lens through which light to be inspected has been transmitted for each of the plurality of light fluxes by using the interference signal.