Hitachi, Ltd.

Hitachi Electronics Engineering Co., Ltd.

Kyo Suda

Katsumi Takami

Yasuo Yatsugake

Shinobu Hase

Susumu Saito

Yoshitoshi Ito

Michio Suzuki

Shigeharu Kimura

Yuzo Taniguchi

Chusuke Munakata

Hiroto Nagatomo

Akira Shintani

Kazuya Tsukada

Kanji Kinameri

Fukuo Iwaya

Kensaku Takahashi

Mikihito Saito

Makoto Ito

Hideo Takizawa

Kenji Aiko

A laser length measuring instrument in which a first and a second sinusoidal wave interference signals differing in phase by .pi./2 are generated from a plurality of interference wave signals received from an interferometer; a plurality of third sinusoidal wave interference signals differing in phase by m.pi./2 n (where n=integer 2 or greater; m=positive integer sequentially selected from among 0&lt;m.pi./2n&lt;.pi.) with respect to the first sinusoidal wave interference signal are generated out of the first and the second sinusoidal wave interference signals in a phase difference signal generating circuit; a signal indicating the polarity inversion of each sinusoidal wave interference signal is generated, out of the plurality of third sinusoidal wave interference signals generated therein, and the first and the second sinusoidal wave interference signals, utilizes a polarity inversion signal generating circuit to render the signal indicating the polarity inversion corresponding to either first or second sinusoidal wave interference signal into a first measuring signal, and the signal indicating a plurality of polarity inversions respectively corresponding to the plurality of third sinusoidal wave interference signals, and the first and the second sinusoidal wave interference signals into a second measuring signal. The two kinds of measuring signals are combined for measuring purposes to suppress the accumulation of errors affecting the results of measurement in order to obtain accurate, high-resolution displacement measuring data which is hardly affected by signal detection errors on the whole.

Laser length measuring instrument

A pattern defect inspection apparatus detects presence or absence of a defect in a pattern formed on a semiconductor wafer by scanning the pattern normally to the surface thereof by a coherent light beam of a predetermined spot size, detecting reflected diffraction lights generated thereby and processing the detected lights. It comprises an abnormal direction signal detector including photo-detectors having wide light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from a normal pattern do not normally reach, a normal pattern detector including photo-detectors having large light receiving areas arranged in a plurality of spatial areas which the reflected diffraction lights from the normal pattern reach, and a defect discriminator for determining if the abnormal direction signals are due to a true defect or not in accordance with the signals from the abnormal direction signal detector and the normal pattern detector.

Pattern defect inspection apparatus

In a small particle detection system for use in detecting small particles, which float in a gas, by utilizing the light scattering effect thereof, a detecting cell is disposed in an external optical resonator which is adapted to resonate with the output light from a laser oscillator. When the detecting cell is disposed in the laser oscillating optical resonator, the position is selectively determined; the former is set in the position in the latter in which the diameter of a laser beam is minimal.

Small particle detection system

A light beam scanning apparatus projects a light beam swept by a light scanner to a spherical mirror and scans by a light beam spot reflected and focused by the spherical mirror a surface of an object arranged to oppose to the spherical mirror at a position spaced from the spherical mirror by a distance equal to a focal distance f of the spherical mirror. An optical path length between the light scanner and the spherical mirror is set to 0.78 f-0.84 f to minimize a curvature of field (circle of confusion).

Light beam scanning apparatus and the method

In forming a film of a purposive substance on a substrate by a chemical vapor deposition (CVD), the size of the film-forming substance particles formed in a reactor is detected as an electrical signal and flow rates of respective gases introduced into the reactor are controlled in response to this electrical signal. According to this control method, the fogging phenomenon owing to formation of the film-forming substance in the gas flow can be effectively prevented.

Method for controlling chemical vapor deposition

Growing community of inventors

Hachioji, Japan

Kyo Suda