초록 ▼

Disclosed is a horizontal position detecting device for maintaining the surface of a body to be inspected vertically to the optical axis of a main objective lens. The device includes an illumination optical system and a condenser lens system. The illumination optical system supplies parallel light r

Disclosed is a horizontal position detecting device for maintaining the surface of a body to be inspected vertically to the optical axis of a main objective lens. The device includes an illumination optical system and a condenser lens system. The illumination optical system supplies parallel light rays to the surface of the body from the direction oblique to the optical axis of the objective lens. The condenser lens system condenses the light rays supplied by the illumination optical system and reflected by the surface of the body. The optical axes of the illumination optical system and the condenser lens system are arranged substantially symmetrically with respect to the axis of the objective lens.

대표청구항 ▼

1. A leveling device for maintaining the surface of an object to be inspected vertically relative to the optical axis of an image forming means comprising: support means for supporting the object so as to be able to control the inclination of the object surface with respect to said optical axis o

1. A leveling device for maintaining the surface of an object to be inspected vertically relative to the optical axis of an image forming means comprising: support means for supporting the object so as to be able to control the inclination of the object surface with respect to said optical axis of said image forming means; an illuminating optical system having an optical axis obliquely arranged to the optical axis of said image forming means for supplying parallel light rays to the object surface from a direction oblique to the optical axis of said image forming means; a condenser optical system having an optical axis arranged symmetrically with said optical axis of said illumination optical system with respect to said optical system of said image forming means for condensing the parallel light rays supplied from said illuminating optical system and reflected on said object surface, said condenser optical system including converging unit for converging the parallel light rays reflected on said object surface and a light receiving member disposed at the position where said parallel light rays are converged by said converging unit and generating signals corresponding to the position of said converged light rays; and control means for controlling said support means based on the signals generated by said light receiving member so as to maintain the position of said converged light rays at a predetermined position on said light receiving member. 2. A leveling device according to claim 1, in which the illumination optical system comprises a light source, a condensing lens to form the image of the light source, a stop having a pin hole disposed at a position where the light source image is formed, and an illuminating objective lens, of which the focal point coniciding with the position of said pin hole of the stop. 3. A leveling device according to claim 2 further comprising a first beam splitter located between the illuminating objective lens and the stop in the illumination optical system; a second beam splitter located between the condensing objective lens and the light receiving element in the condenser optical system; a projection optical system for projecting an aperture image on the surface of the object to be inspected through the first beam splitter and the illuminating objective lens; and an image forming, optical system for focussing the aperture image projected on the surface of the body on another light receiving element. 4. A leveling device according to claim 3, in which said first and second beam splitters are dichroic mirrors, respectively, and said projection optical system has a light source producing a light having a wave length different from a wave length of the light emitted from the light source in the illumination optical system. 5. A leveling device according to claim 1, wherein said converging unit includes a condenser objective lens for condensing the parallel light rays reflected on said object surface at a rear focal plane of the condenser objective lens, a filtering stop for eliminating diffraction lights caused on the object surface, disposed at the rear focal point of said condenser objective lens, and a condenser lens for forming a conjugate position with said rear focal point of the condenser objective lens with respect to the condenser lens, and wherein said light receiving member is disposed at the conjugate position with said rear focal point of the condenser objective lens. 6. A leveling device according to claim 5, wherein said illuminating optical system illuminates a region of the object surface which region is substantially equal to the region inspected through said image forming means. 7. A leveling device for projection type exposure apparatus including projection objective means, a reticle having a projection pattern thereon and a wafer disposed to receive on a predetermined region thereof a projected image of said projection pattern of said reticle through said projection objective means, said leveling device comprising: support means for supporting the wafer so as to be able to control the inclination of the wafer with respect to the optical axis of said projection objective means; an illuminating optical system having an optical axis obliquely arranged to the optical axis of said projection objective means for supplying parallel light rays to the wafer from a direction oblique to the optical axis of said projection objective means; a condenser optical system having an optical axis arranged symmetrically with said optical axis of said illumination optical system with respect to said optical axis of said projection objective means for condensing the parallel light rays supplied from said illuminating optical system and reflected on said wafer, said condenser optical system including converging unit for converging the parallel light rays reflected on said wafer and a light receiving member disposed at the position where said parallel light rays are converged by said converging unit for generating signals corresponding to the position of said converged light rays; and control means for controlling said support means based on the signals generated by said light receiving member so as to maintain the position of said converged light rays at a predetermined position on said light receiving member. 8. A leveling device according to claim 7, wherein said illuminating optical system illuminates the region on the wafer which region is substantially equal to said predetermined region of the wafer on which the image of said projection pattern of said retical is to be projected. 9. A leveling device according to claim 8, wherein said converging unit includes a condenser objective lens for condensing the parallel light rays reflected on said wafer at a rear focal plane of the condenser objective lens, a filtering stop member, for eliminating diffraction lights caused on the wafer, disposed at the rear focal point of said condenser objective lens, and a condenser lens for forming a conjugate position with said rear focal point of the condenser objective lens with respect to the condenser lens, and wherein said light receiving member is disposed at the conjugate position with said rear focal point of the condenser objective lens. 10. A leveling device according to claim 9, wherein said illuminating optical system comprising, a light source, a condensing lens to form the image of the light source, a stop having a pin hole disposed at a position where the light source image is formed, and an illuminating objective lens, of which the focal point coinciding with the position of said pin hole of the stop. 11. A leveling device according to claim 10, further comprises a first beam splitter located between the illuminating objective lens and the stop having a pin hole in the illumination optical system; a second beam splitter located between the condenser objective lens and the light receiving element in the condenser optical system; a projection optical system for projecting a linear aperture image on the wafer through the first beam splitter and the illuminating objective lens; and an image forming optical system for focusing the linea aperture image projected on the wafer onto another light receiving element through said condenser objective lens and said second beam splitter. 12. A leveling device according to claim 11, wherein said image forming optical system includes an oscillating mirror for oscillating the linear aperture image on the light receiving surface of said another light receiving element, and wherein said another light receiving element generates signals corresponding to the focusing condition of the wafer relative to said projection objective means. 13. A leveling device according to claim 11, wherein said first and second beam splitters are dichroic mirrors, respectively, and said projection optical system has a light source emitting a light having a wave length different from a wave length of the light emitted from the light source in the illuminating optical system. 14. A leveling device according to claim 13, wherein a wave length of the exposure light of said exposure apparatus is different from both wave length of the illuminating optical system and wave length of said projection optical system.