Apparatus for measuring thickness and surface profile of multilayered film structure using imaging spectral optical system and measuring method

An apparatus for measuring a thickness and a surface profile of a multilayered film structure using an imaging spectral optical system to obtain thickness information and surface profile information of an object to be measured coated with a thin film, the apparatus comprising:

• an illumination optical module having a light source which emits light;
• an interferometer module having a beam splitter which splits light emitted from the illumination optical module, a reference mirror which emits second reflected light by causing some light split by the beam splitter to be incident thereon and then reflecting the light, and a blocking plate which selectively blocks the some light which is incident onto the reference mirror;
• a piezoelectric actuator which changes a distance between the interferometer module and the object to be measured configured by a multilayered thin film;
• a plate driver which drives the blocking plate to selectively block the some light which is incident onto the reference mirror;
• and
• an imaging spectrometer module which causes the remaining light of the split light to be incident onto an object to be measured covered with a thin film and then obtains first reflected light obtained by light reflected from an upper layer and a lower layer of the thin film being interfered with each other and obtains interference light obtained by combining the first reflected light and the second reflected light to calculate an absolute reflectance value from an interference fringe of the first reflected light and extract a phase component value having thickness information and surface profile information from the interference fringe of the interference light, measure thin film thickness information from the absolute reflectance value and the phase component value, and measure thin film surface profile information from the measured thin film thickness information and the phase component value.