Hitachi, Ltd.

Masaaki Itou

Shigeo Moriyama

Tsuneo Terasawa

Soichi Katagiri

Hiroaki Oizumi

Hiroshi Fukuda

Shinji Okazaki

Kozo Mochiji

A semiconductor wafer includes a top surface on which a semiconductor circuit pattern is to be fabricated, and a bottom surface on which alignment marks for positioning the semiconductor circuit pattern are arranged. The alignment marks are arranged at a predetermined pitch and in an arrangement that is not unique to the pattern formed on the top surface.

Workpiece having alignment marks for positioning a pattern at a

Reduction projection type X-ray lithography with an exposing beam wavelength of 40-150A, longer than in conventional 1:1 proximity exposure, has a high-vacuum space. This would reduce wafer replacement work efficiency and contaminate optical mirrors with substances released by a resist decomposed during exposure except for separating an optical system chamber and a wafer exposing chamber by a differential pumping section and a thin-film window. Wafer exposure is under atmospheric pressure, improving productivity, accuracy of exposure and longevity of the optical devices.

Projection type X-ray lithography apparatus

In a reflection mask, there is formed at least one laminate structure comprising a high reflectivity portion, a middle portion and a high reflectivity portion. When there is a defect in the high reflectivity portion as the top layer, this high reflectivity portion and the underlying middle portion are removed in that defective position, thereby allowing the high reflectivity portion as the bottom layer to be exposed to repair the defect.

Reflection mask

In printing patterns on a mask onto a wafer with high accuracy via a reflective reduction projection optical system by using an X-ray or vacuum ultraviolet beam there is an elliptical mirror having a source position defined in an X-ray source and a position of reflection image of entrance pupil of an imaging optical system with respect to the mask as foci and introducing means for synchronously scanning the mask and wafer. Due to inserting a plane mirror for bending an X-ray by approximately 90.degree. at at least one point in the imaging optical system so that the plane of incidence may be perpendicular to the polarization plane the reflectivity does not lower even when the angle of incidence is 45.degree.. A reflecting mirror or an X-ray filter having a lower reflectivity in the peripheral part thereof as compared with the reflectivity of the central part thereof in the stop position of the imaging optical system, brings about an effect of lessened influence of mutual interference between adjacent pattern provides pattern printing with high shape accuracy.

X-ray pattern masking by a reflective reduction projection optical system

A method for detecting position detection marks on the bottom surface of a sample substrate and for determining the pattern forming positions on the top surface of the sample on the basis of the detected mark positions makes it possible to virtually eliminate the measurement errors caused by sample tilt in the position measurements regarding the sample top surface. When the sample tilts, a positional difference occurs between the top and bottom surfaces of the sample, and errors are accordingly generated in the position measurements from the sample top surface. According to the invention, the mark position measurements from the sample bottom surface are made to contain a deviation that varies with the tilt angle of the sample. The deviation is used to cancel the errors in the measured positions.

Method of position detection and the method and apparatus of printing

An X-ray exposure apparatus comprises an X-ray source, a reflecting mirror for deflecting an X-ray beam radiated from the X-ray source to an object, and mechanisms for rotating the reflecting mirror about an axis of rotation apart from a reflecting surface of the reflecting mirror. The reflecting mirror has such a shape that the angle of incidence remains constant relative to the X-ray beam at given angles of rotation.

Growing community of inventors

Higashimurayama, Japan

Masaaki Itou