# US 5,703,675 A · Projection-exposing apparatus with deflecting grating member > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,703,675 A - Document ID: US5703675A - Status: Granted - Kind: A - Application number: 08/476,908 - Filed: 1995-06-07 - Granted: 1997-12-30 - Earliest claimed: 1992-01-17 - Assignees: Nikon Corporation - Inventors: Shigeru Hirukawa; Naomasa Shiraishi; Masaomi Kameyama - Web page: https://patentgrep.com/patent/US5703675A ## CPC - G03F 7/70358: {Scanning exposure, i.e. relative movement of patterned beam and workpiece during imaging} - G03F 7/70108: {Off-axis setting using a light-guiding element, e.g. diffractive optical elements [DOEs] or light guides} - G03F 7/70225: {Optical aspects of catadioptric systems, i.e. comprising reflective and refractive elements} - G03F 7/70333: {Focus drilling, i.e. increase in depth of focus for exposure by modulating focus during exposure [FLEX]} - G03F: PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR; (phototypographic composing devices B41B; photosensitive materials or processes for photographic purposes G03C; electrophotography, sensitive layers or processes therefor G03G) ## Abstract A projection-exposing apparatus has a mask which has a pattern formed with a pitch P.sub.R, an illuminating optical system for applying illuminating light from a light source to the mask, a projection optical system for projecting an image of the pattern onto a photosensitive substrate, and a deflecting grating member formed with a pitch P.sub.G disposed between the light source and the pattern of the mask for generating diffracted light. The pitch P.sub.G of the deflecting grating member is defined in the relation P.sub.G =2P.sub.R. The diffraction grating member is remote from the pattern on the mask by a distance .DELTA.t, where .DELTA.t .gtoreq.P.sub.G /2NA.sub.IL, NA.sub.IL being the numerical aperture of the illumination optical system. ## Claims ### Claim 1 A projection exposure apparatus comprising: an illumination optical system for applying illuminating light from a light source onto a mask; a projection optical system for projecting an image of a pattern on said mask onto a photosensitive substrate; and a diffraction grating plate disposed on the light source side and remote from the pattern on said mask by a distance .DELTA.t, wherein the following condition is established: .DELTA.t.gtoreq.P.sub.G /2NA.sub.IL wherein P.sub.G : pitch of said diffraction grating plate, NA.sub.IL : numerical aperture of said illumination optical system. ### Claim 2 (depends on 1) An apparatus according to claim 1, further comprising a moving device for moving an image plane of said projection optical system and said photosensitive substrate relative to each other, in a direction of an optical axis of said projection optical system. ### Claim 3 (depends on 1) An apparatus according to claim 1, further comprising a movable member for moving said diffraction grating plate relative to the pattern on said mask. ### Claim 4 (depends on 1) An apparatus according to claim 1, wherein the pattern on said mask is comprised of a transmitting portion, and a semi-transmitting portion which gives a phase difference of the illuminating light and of which the transmittance to the illuminating light is equal to or less than the order of 1/4 of the transmittance of said transmitting portion. ### Claim 5 A projection-exposing apparatus comprising: a mask which has a pattern formed with a pitch P.sub.R ; an illuminating optical system for applying illuminating light from a light source to said mask; a projection optical system for projecting an image of said pattern onto a photosensitive substrate; and a deflecting grating member formed with a pitch P.sub.G, disposed between the light source and the pattern of said mask with a predetermined spacing therefrom, for generating .+-.1st-order and higher order diffracted light; wherein said pitch P.sub.G of said deflecting grating member is defined in the relation P.sub.G =2P.sub.R. ### Claim 6 (depends on 5) The projection-exposing apparatus of claim 5, wherein a coherence factor of said illuminating optical system is determined to the order of 0.1-0.3. ### Claim 7 (depends on 5) The projection-exposing apparatus of claim 5, wherein said deflecting grating member is a diffraction grating pattern formed on a substrate substantially transparent to said illuminating light. ### Claim 8 (depends on 7) The projection-exposing apparatus of claim 7, further comprising: a holding member for holding said substrate, said holding member being rotatable in a plane perpendicular to the optical axis of said projection optical system. ### Claim 9 (depends on 8) The projection-exposing apparatus of claim 8, wherein said holding member holds said substrate so that the spacing .DELTA.t between the pattern of said mask and said diffraction grating pattern with respect to the direction of the optical axis of said projection optical system may satisfy the relation that .DELTA.t.gtoreq.P.sub.G /2NA.sub.IL, where NA.sub.IL is the numerical aperture of said illuminating optical system. ### Claim 10 (depends on 5) The projection-exposing apparatus of claim 5, further comprising: a light intercepting member provided between said projection optical system and said deflecting grating member for intercepting the expanse of the light beam by said deflecting grating member. ### Claim 11 (depends on 10) The projection-exposing apparatus of claim 10, wherein said light intercepting member is a light intercepting zone formed on said mask. ### Claim 12 (depends on 10) The projection-exposing apparatus of claim 10, wherein said light intercepting member is comprised of a plurality of movable blades. ### Claim 13 (depends on 5) The projection-exposing apparatus of claim 5, further comprising: a limiting member for limiting the side of the area of incidence of said illuminating light onto said deflecting grating member so that said area of incidence may be larger by a predetermined amount than the formation area of the pattern of said mask. ### Claim 14 (depends on 5) The projection-exposing apparatus of claim 5, further comprising: an adjusting device for making a coherence factor of said illuminating optical system variable. ### Claim 15 (depends on 14) The projection-exposing apparatus of claim 14, wherein said adjusting device varies the coherence factor of said illuminating optical system within a range of 0.1-0.7. ### Claim 16 (depends on 14) The projection-exposing apparatus of claim 14, wherein said adjusting device is a variable aperture stop provided in or near the Fourier transformation plane in said illuminating optical system for the pattern of said mask. ### Claim 17 (depends on 14) The projection-exposing apparatus of claim 14, wherein said illuminating optical system includes an optical integrator, and said adjusting device is a zoom lens system for making the beam diameter of the illuminating light incident on said optical integrator variable. ### Claim 18 (depends on 14) The projection-exposing apparatus of claim 14, wherein said adjusting devices includes a variable aperture stop for making the beam diameter of said illuminating light in said illuminating optical system variable, and a changing device for changing the aperture diameter of said variable aperture stop in conformity with the kind of said deflecting member. ### Claim 19 (depends on 5) The projection-exposing apparatus of claim 5, further comprising: an interchange device for interchanging said deflecting grating member in conformity with the pattern of said mask. ### Claim 20 A projection-exposing apparatus comprising: a mask which has a pattern formed with a pitch P.sub.R ; an illuminating optical system for applying illuminating light from a light source to said mask; a projection optical system for projecting an image of said pattern onto a photosensitive substrate; a deflecting grating member formed with a pitch P.sub.G, disposed between the light source and the pattern of said mask with a predetermined spacing therefrom, for generating .+-.1st-order and higher order diffracted light; and a movable device holding said deflecting grating member and movable in a predetermined direction and/or rotatable in a plane perpendicular to an optical axis of said projection optical system; wherein said pitch P.sub.G of said deflecting grating member is defined in the relation P.sub.G =2P.sub.R. ### Claim 21 (depends on 20) The projection-exposing apparatus of claim 20, wherein said movable device includes a holding member for holding said deflecting grating member, and a driving device for driving said holding member while the pattern of said mask is exposed onto said photo-sensitive substrate. ### Claim 22 A projection-exposing apparatus comprising: a mask which has a pattern formed with a pitch P.sub.R ; an illuminating optical system for applying illuminating light from a light source to said mask; a projection optical system for projecting an image of said pattern onto a photosensitive substrate; the pattern of said mask being comprised of a transmitting portion of which the transmittance to said illuminating light is approximately 1, and a semi-transmitting portion which gives a phase difference of approximately (2m+1).pi.(m being an integer) to the illuminating light transmitted through said transmitting portion and of which the transmittance to said illuminating light is equal to or less than the order of 1/4 of the transmittance of said transmitting portion; and a deflecting grating member formed with a pitch P.sub.G, disposed between the light source and the pattern of said mask, with a predetermined spacing therefrom, for generating .+-.1st-order and higher order diffracted light; wherein said pitch P.sub.G of said deflecting grating member is defined in the relation P.sub.G =2P.sub.R. ### Claim 23 A projection-exposing apparatus comprising: a mask which has a pattern formed with a pitch P.sub.R ; an illuminating optical system for applying illuminating light from a light source to said mask; a projection optical system for projecting an image of said pattern onto a photosensitive substrate; a scanning system moving said mask and said photosensitive substrate in synchronization with each other, in order to expose said photosensitive substrate with said pattern image; and a diffraction grating plate formed with a pitch P.sub.G, disposed between the light source and the pattern of the mask for generating, when said illuminating light is incident, .+-.1st-order and higher order diffracted light; wherein said pitch P.sub.G of said diffraction grating plate is defined in the relation P.sub.G =2P.sub.R. ### Claim 24 (depends on 23) The projection-exposing apparatus of claim 23, wherein said diffraction grating plate is such that the formation area of the diffraction grating thereof for generating said diffracted light is determined to an arcuate shape or a rectangular slit-like shape. ### Claim 25 (depends on 24) The projection-exposing apparatus of claim 24, wherein the formation area of said diffraction grating is determined to a size equal to or larger than the degree of the illuminated area of the pattern of said mask. ### Claim 26 (depends on 23) An apparatus according to claim 23, wherein said scanning system includes a mask stage movable for carrying said mask, a substrate stage movable for carrying said photosensitive substrate, and a driving device for driving said mask stage and said substrate stage with a speed ratio corresponding to a magnification of said projection optical system.