| 摘要 |
PURPOSE:To accurately measure the surface cleanness degree of a specimen without relying on visual observation, by allowing a specimen to emit electrons from the entire surface thereof by applying energy having a specific value to said specimen and detecting electrons from the surface not covered with a contamination layer. CONSTITUTION:A specimen 7 having a contamination layer 9 adhered to a part of the surface thereof is irradiated with monochromatic light, which has energy equal to or more than the photoelectric function of the specimen but below that of the contamination layer 9, from a light source 10 through a spectroscope 11 and slits 12. Then, the electrons from the part covered with the contamination layer 9 are caught while electrons are allowed to discharge from the uncovered surface of the specimen 7 and the number of said discharged electrons are counted by a count means 16 through grid electrodes 6, 8, pulse generators 14, 15 and an amplifier 16 while the calculated result is outputted to an operation means 17 which in turn performs operation based on formula T=N/N1 (wherein N is the count number when the number of electrons from the surface not covered with the contamination layer are detected and N1 is the count number when the surface of the specimen is a perfectly cleaned one) to calculate a cleanness degree T. By this method, the surface cleanness degree of the specimen can be accurately measured. |
