Abstract: Disclosed is an electron beam metrology system for measuring the width of a pattern on a specimen by scanning the specimen with a deflected electron beam, detecting a pattern image signal provided by secondary electrons emitted from the specimen, and measuring the pattern width on the specimen on the basis of the pattern detection signal. The system comprises a signal detecting device including at least one set of two detectors disposed toward the scanning direction of the electron beam in a relation symmetrical with respect to the optical axis of the electron beam for detecting pattern image signals independently of each other, a device for recognizing surface topography of the pattern using an output signal of the signal detecting device, and a device for measuring the pattern width while discriminating as to whether the pattern is a raised-profile pattern or a hollow-profile pattern.

Abstract: An electron beam metrology system for measuring the width of a pattern on a surface of a sample in such a manner that the surface of the sample is scanned with an electron beam, secondary electrons emitted from the surface are detected to obtain a detection signal, and the width of the pattern is measured by using the detection signal, is disclosed in which a pair of detectors are disposed symmetrically with respect to the optical axis of the electron beam in a scanning direction thereof, a ratio of one of the output signals of the detectors to the other output signal and a ratio of the other output signal to the one output signal are formed, and a sum signal indicative of the sum of two ratios is produced, to be used for measuring the width of the pattern correctly and accurately, without being affected by a change in pattern material.

Abstract: Disclosed is an apparatus for focusing a charged particle beam onto a speciman, which comprises a scanner for scanning a pre-formed standard pattern with a charged particle beam, a converging unit capable of converging the charged particle beam onto a specimen, a detector for detecting secondary charged particles emitted as a result of scanning the standard pattern by the scanner, a circuit for deriving a standard frequency component determined by the period of scanning with the charged particle beam and the shape of the portion of the standard pattern in the region being scanned with the charged particle beam, and a circuit cooperating with the converging unit for finding the maximum value of the amplitude of the standard frequency component thereby identifying attainment of focusing of the charged particle beam with high accuracy.

Abstract: A small-dimension measurement system by scanning electron beam comprises an electron optical column including an electron source for emitting an electron beam to scan a sample, at least one pair of detectors disposed symmetrically with respect to an optical axis of the electron optical column for detecting position information from the sample by scanning of the electron beam, and a signal selecting circuit for subjecting the outputs of the paired detectors to a predetermined signal selection. The signal selecting circuit selectively and alternately provides maximum or peak portions of the outputs of the paired detectors which portions correspond to opposite edge portions of the sample. The output of the signal selecting circuit is applied to a signal processing circuit for conversion into a dimension of a predetermined pattern on the sample.