Projection exposure method and apparatus capable of performing focus detection with high accuracy

A projection exposure apparatus comprising:

• a projection optical system for projecting a pattern of a mask on a photosensitive substrate;
• a stage, for holding the photosensitive substrate, movable in an optical-axis direction of said projection optical system and in a predetermined direction perpendicular to the optical axis;
• a position detection system for outputting a detection signal, corresponding to a deviation between an imaging plane of said projection optical system and a surface of the photosensitive substrate in said optical-axis direction, by projecting a light beam having a predetermined shape on the photosensitive substrate and, at the same time, photoelectrically detecting light reflected from the photosensitive substrate;
• a device for driving said stage in the optical-axis direction of said projection optical system based on the detection signal outputted from said position detection system;
• a fiducial member provided on said stage and having a fiducial pattern assuming a predetermined shape;
• a memorizing device for memorizing positional information regarding said fiducial pattern;
• and
• a device for controlling a movement of said stage through said driving device in accordance with the detection signal outputted from said position detection system when the fiducial pattern and the light beam are relatively moved in the predetermined direction perpendicular to the optical axis of said projection optical system, and based on the positional information memorized in said memorizing device.

A projection exposure apparatus comprising:

• a projection optical system for projecting a pattern of a mask on a photosensitive substrate;
• a stage, for holding the photosensitive substrate, movable in an optical-axis direction of said projection optical system and in a predetermined direction perpendicular to the optical axis;
• a position detection system including a light projecting system for projecting a light beam having a predetermined shape onto said photosensitive substrate and shifting a position irradiated by said light beam within a plane perpendicular to the optical axis of said projection optical system, and a light receiving system for photoelectrically detecting light reflected from said photosensitive substrate, said position detection system outputting a detection signal corresponding to a deviation between an imaging plane of said projection optical system and a surface of the photosensitive substrate in said optical-axis direction;
• a fiducial member provided on said stage and having a fiducial pattern assuming a predetermined shape;
• a device for detecting an irradiation position of the light beam within a plane perpendicular to the optical axis of said projection optical system based on variations in intensity of a detection signal outputted from said position detection system when the fiducial pattern and the light beam are relatively moved in the predetermined direction perpendicular to the optical axis of said projection optical system;
• and
• a driving device for driving said light projecting system to shift the irradiation position of the light beam based on the detected irradiation position.

An exposing method of exposing a pattern of a mask onto a photosensitive substrate through a projection optical system, comprising the steps of:

• projecting a light beam having a predetermined shape onto said photosensitive substrate, opto-electrically detecting light reflected from said photosensitive substrate, and outputting a detection signal corresponding to a deviation between an imaging plane of said projection optical system and a surface of said photosensitive substrate, said deviation being along the optical axis of said projection optical system;
• memorizing positional information regarding a fiducial pattern provided on a stage;
• and
• detecting a position irradiated by said light beam within a plane perpendicular to the optical axis of said projection optical system, in accordance with variations of an intensity of said detection signal when said fiducial pattern and said light beam are relatively moved along a predetermined direction perpendicular to the optical axis of said projection optical system based on the memorized positional information.

A projection exposure apparatus comprising:

• a projection optical system for projecting a pattern of a mask on a photosensitive substrate;
• a stage, for holding the photosensitive substrate, movable in an optical-axis direction of said projection optical system and in a direction perpendicular to the optical axis;
• a focus detection system including a light projecting system for projecting a pattern image onto said photosensitive substrate, and a light receiving system for photoelectrically detecting light reflected from said photosensitive substrate, said focus detection system outputting a detection signal corresponding to a deviation between an imaging plane of said projection optical system and a surface of the photosensitive substrate in the optical-axis direction of said projection optical system;
• a pattern light receiving system having a light receiving plane provided on said stage, for photoelectrically detecting said pattern image;
• a detection system for detecting an imaging status of said pattern image based on a photoelectric signal output from said pattern light receiving system when said pattern image is projected on said light receiving plane;
• and
• a driving member for driving at least one of a plurality of optical elements constituting said light projecting system, along an optical-axis direction of said light projecting system, based on the detected imaging status.

A projection exposure apparatus comprising:

• a projection optical system for projecting a pattern of a mask on a photosensitive substrate;
• a position detection system for projecting a pattern image on said photosensitive substrate and photoelectrically detecting light reflected from said photosensitive substrate so as to detect a position or a positional deviation of said photosensitive substrate in an optical-axis direction of said projection optical system;
• and
• an adjustment device for driving at least one optical element of said position detection system, and adjusting at least one of an imaging status of said pattern image and a position of said pattern image in a plane perpendicular to the optical axis of said projection optical system.

A projection exposure apparatus comprising:

• a projection optical system for projecting a pattern of a mask on a photosensitive substrate;
• a stage, for holding the photosensitive substrate, movable in an optical-axis direction of said projection optical system and in a direction perpendicular to the optical axis;
• a focus detection system for outputting a detection signal corresponding to a deviation between an imaging plane of said projection optical system and a surface of the photosensitive substrate in the optical-axis direction of said projection optical system, by projecting a pattern image on said photosensitive substrate and photoelectrically detecting light reflected from said photosensitive substrate;
• a reflection member provided on said stage and having at least two areas of different reflectivity;
• a memorizing device for memorizing positional information regarding said reflection member;
• a detection system for relatively scanning said pattern image and said reflection member based on the positional information memorized in said memorizing device, and detecting an imaging status of said pattern image based on a photoelectric signal output from said focus detection system caused by said scanning;
• and
• an adjustment device for adjusting a focal point of said pattern image on said photosensitive substrate based on said detected imaging status.