| 摘要 |
PURPOSE:To measure length between 2 points exactly and quickly, by reflecting an image of a sample on a screen of a cathode ray tube, and moving the first and second markers reflected by brilliance modulation, to each part corresponding to the end part between 2 points of this image, respectively. CONSTITUTION:A wafer 21 is placed in a barrel CM of a scanning-type electronic microscope, and is scanned by an electronic beam 14 in accordance with signals from saw-tooth wave generating circuits 5, 6. A secondary electron goes into a detector 22, pases through amplifiers 23, 24, and reflects a pattern image 59 on a picture 9a of a cathode ray tube 9. By a marker generating circuit 25, marks MK1, MK2 are generated on the picture, and can be moved to a position of an object to be measured. By a threshold level deciding circuit 29 set by a control panel 38, a threshold level is set to a suitable position of a video signal Aa of a pattern, is binary-coded, a mark signal of both sides of a pattern line is detected by a circuit pattern measuring circuit 48, and width of the pattern is operated and displayed 57 by an operating circuit 52. |
