Horizontal position detecting device
AssigneeNippon Kogaku K.K.
InventorsMakoto Uehara, Takeshi Sudo, Fujio Kanatani
Life of this patent
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Abstract
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.
Claims14
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.
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.
Dependencies are inferred from the claim text.