| 摘要 |
PURPOSE:To improve the measuring accuracy of dimensions on an element having high surface irregularity and roughness by forming a cross section being a reference for measurement on a transparent coat formed on a specimen to be measured and forming the mirror image of the specimen to be measured on the cross section. CONSTITUTION:The transparent coat 2 with its surface LM flat is formed on the specimen 1 to be measured. A boundary part MN is formed in a flat shape by machining. When light beams u1-u3 are made incident on the surface LM of the specimen to be measured, the reflected light beams turn out to be v1-v3. The reflected light beam v3 is total-reflected on the boundary part MN and made into the light beam from a mirror image a' at a point (a), and the light beam u3 and the reflected light beam v3 approach each other in parallel. When the reflected light beam is projected on the screen of the monitor television of a micro scope not shown in figure, a dark part 15 with an excellent contrast and micro width can be obtained on an intermediate part of an actual image (a) and the mirror image a' with respect to the dark parts of staged parts (c) and (d) in terms of patterns (a)-(d). With this dark part 15 as a reference position distances w1 and w2 up to arbitrary points are measured. Thus the accuracy of the dimension measurement of the element having surface irregularity and roughness can be improved. |
