Nikon Corporation

Masaya Komatsu

Satoru Anzai

Kyoichi Suwa

Kazuo Ushida

Masato Shibuya

Hiroshi Ooki

Masaomi Kameyama

Toshihiko Ozawa

Yoshifumi Tokoyoda

An exposure method comprises the steps of: providing a resist-coated substrate; providing a first mask including first and second regions having respective patterns formed therein; conducting a first exposure process in which the patterns in the first and second regions of the first mask are projected onto the substrate so as to expose first and second regions of the substrate which correspond to the patterns, respectively; and conducting a second exposure process after completion of said first exposure process so as to make an additional exposure of the second region of the substrate. By virtue of the incorporation of the second exposure process so as to make an additional exposure of the second region of the substrate, the resist linewidth which would be otherwise produced in the second region of the substrate by the first exposure process can be compensated through the second exposure process.

Exposure method

The present invention relates to a projection exposure method and an exposure apparatus for projecting a pattern on a photo-mask through a projection optical system onto a predetermined photosensitive material. The photosensitive material is a nonlinear photosensitive material in which the effective light intensity distribution is nonlinear to the intensity of incident exposure light. Further, multiple exposure is made with plural patterns having a certain lateral shift therebetween, or multiple exposure is made with shifting the position of an identical pattern, whereby multiple exposure is effected with patterns different in intensity distribution on the photosensitive material. A high-resolution pattern can be formed over the resolution limit of projection optical system by the above arrangement.

Exposure method and apparatus

A photomask is provided having a stepped portion formed on at least one of a first and second areas corresponding to a stepped structure within an exposure area on the sensitive substrate onto which the pattern is to be exposed to make different height positions of the first and second areas of the pattern forming surface of the transparent substrate in the optical axis direction of the projection optical system. Also provided is an exposure method involving the step of shifting an image forming surface of a projection optical system in an optical axis direction corresponding to a stepped structure of an exposure area on a sensitive substrate, The image forming surface of the projection optical system coincides with the exposure area surface when exposing the pattern on an original substrate onto the sensitive substrate through the projection optical system. A projection exposure apparatus is also provided including a projection optical system for projecting and forming an image of a pattern on the original substrate on the sensitive substrate, and a stage for retaining the sensitive substrate so that the surface of the sensitive substrate is disposed close to the image forming surface, The exposure apparatus also has an image surface compensating member for shifting the image forming surface in the optical axis direction corresponding to the stepped structure.

Photomask, an exposure method and a projection exposure apparatus

A photomask is provided having a stepped portion formed on at least one of a first and second areas corresponding to a stepped structure within an exposure area on the sensitive substrate onto which the pattern is to be exposed to make different height positions of the first and second areas of the pattern forming surface of the transparent substrate in the optical axis direction of the projection optical system. Also provides is an exposure method involving the step of shifting an image forming surface of a projection optical system in an optical axis direction corresponding to a stepped structure of an exposure area on a sensitive substrate. The image forming surface of the projection optical system coincides with the exposure area surface when exposing the pattern on an original substrate onto the sensitive substrate through the projection optical system. A projection exposure apparatus is also provided including a projection optical system for projecting and forming an image of a pattern on the original substrate on the sensitive substrate, and a stage for retaining the sensitive substrate so that the surface of the sensitive substrate is disposed close to the image forming surface. The exposure apparatus also has an image surface compensating member for shifting the image forming surface in the optical axis direction corresponding to the stepped structure.

A phase-shifted photo mask capable of discrimination between phase shifting portions and a transparent portion (a bare surface portion of a substrate) by microscope observation with visible light. An SOG (spin-on-glass) layer mixed with inorganic colored ions (Co.sup.2+, Mn.sup.3+, Ni.sup.2+ or the like) having an absorption characteristic to the visible light is formed on the surface of the substrate which is substantially transparent to an exposure light (ultraviolet light) and the undesired portions of the SOG layer excluding the portions which are to form the phase shifting portions are removed.

Growing community of inventors

Tokyo, Japan

Masaya Komatsu