| 摘要 |
<p>PURPOSE:To discriminate the flaw of a phase member by irradiating a phase shift mask with inspection light to compare the phase difference detection signal obtained from the transmitted light from said mask with a reference signal. CONSTITUTION:Inspection lights L3, L4 are allowed to irradiate a phase shift mask 33 through an XY stage 32 to transmit through the pattern formed to the mask and receive a phase change at this time to be incident to phase difference microscopes 34a, 34b and the phase difference data thereof are converted to the intensities of lights and these intensities are detected by photodetectors 35a, 35b to be inputted to an image processing circuit 36. The circuit 36 collects the phase difference data over the whole of the pattern and respectively stores the images due to the inspection lights L3, L4 in image memories 37a, 37b. Subsequently, the image of the former is compared with the image of the latter by a comparison circuit 38 and the flow of the phase part of the mask 33 is detected from the comparison result by a flow detection circuit 39.</p> |
