METHOD AND SYSTEM FOR MEASURING AERIAL IMAGE USING TRANSMITTED LIGHT AND REFLECTED LIGHT

PROBLEM TO BE SOLVED: To inspect the effect of various defects on a pattern by irradiating a photomask with the light from a light source, covering selected one of transmitted light or reflected light into an electric signal and forming an aerial image. SOLUTION: Light from a light source 102 is split through a beam splitter 160 into a light passing through a transmitted light path 100A and a light passing through a reflected light path 100B. The paths 100A, 100B are arranged, respectively, with on/off blinkers 170A, 170B for passing or blocking the transmitting light. The light passing through the reflected light path 100B is reflected on a reflector 162 toward the surface of a chromium pattern 152 on a photomask 150. The reflected light is transmitted, along with the light passing through the transmitted light path 100A of a light transmitting means 180 and transmitted through the photomask 150, to a CCD camera 130 through an objective lens 112, a tubular lens 114, etc. Consequently, an aerial image is formed and the defective state is grasped by means of an aerial image measurement system 140.