Hitachi, Ltd.

Nippon Telegraph and Telephone Public Corporation

Tsuneo Okubo

Norio Saitou

Susumu Ozasa

Haruo Yoda

Yasuo Kato

Nobuo Shimazu

Kazuo Ichino

Tadahito Matsuda

Genya Matsuoka

Nobuo Hamamoto

An exposure method with an electron beam exposure apparatus in which an electron beam is emitted onto a substrate such as a silicon wafer on which an electron-beam sensitive resist is coated, thereby directly forming or writing patterns. A substrate having thereon a number of chips are divided into blocks, which each contain a plurality of chips. Marks are provided on each of the blocks, the positions of the marks are detected and the writing exposure positions of the chips within each block are modified on the basis of the detection results. According to this invention, efficient writing exposure can be made with high accuracy.

Exposure method with electron beam exposure apparatus

A method and apparatus of deflection calibration for a charged particle beam exposure apparatus having an electromagnetic deflector and an electrostatic deflector both for deflecting a charged particle beam and a movable stage structure. The electromagnetic deflector is previously subjected to a calibration operation known per se. With a fiducial mark positioned in a predetermined location, the beam is deflected by the calibrated electromagnetic deflector instead of moving the stage structure, the beam is then deflected by the electrostatic deflector to detect the location of the fiducial mark, and deflection data are measured of the electrostatic deflection for the detection of the location of the fiducial mark. According to the present invention the calibration is performed in a short time without causing degradation of the precision of, e.g., lithography due to heat generated by movement of the stage structure.

Method and apparatus of deflection calibration for a charged particle

A method of measuring the diameter of an electron beam in which the electron beam diameter is measured from the leading edge or trailing edge of a detector signal that is obtained as the mark area formed on the specimen is scanned by the electron beam. This method comprises the following steps: scanning the specimen by the electron beam at least once to find the maximum and minimum values of the detector signal; setting two threshold levels based on the maximum and minimum values; scanning the mark area by the electron beam to measure the time interval during which the level of the detector signal is within the two threshold levels; and calculating the beam diameter.

Method and system for measuring the diameter of an electron beam

This invention relates to a method of detecting a mark by an electron beam, the mark being provided on a sample, which includes the steps of scanning the electron beam over an area of the mark in such a manner that the electron beam is subjected to chopping by sampling pulses having a higher frequency than the scanning frequency, eliminating a component of noise from a detected signal representative of the mark, synchronously rectifying the detected mark signal, binary-coding the detected mark signal as compared with a suitable threshold value, and detecting a position of the mark by using the binary-coded signal.

Method of detecting a mark by an electron beam and an apparatus therefor

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Hachioji, Japan

Tsuneo Okubo