Exposure apparatus

An exposure apparatus for printing a pattern of a mask on a wafer, said apparatus comprising:

• a mask chuck for holding the mask;
• a mask stage for moving said mask chuck;
• a wafer chuck for holding the wafer;
• a wafer stage for moving said wafer chuck along a coordinate system;
• laser interferometric distance measuring means for producing data related to a change in position of said wafer chuck in the coordinate system when said wafer chuck is moved by said wafer stage;
• a photoelectric detector, movable integrally with said wafer chuck when said wafer chuck is moved by said wafer stage, for receiving a light beam and for producing an output;
• a frame member for supporting said mask stage and said wafer stage;
• a light emitting element fixed to and provided integrally with said frame member, for projecting a light beam toward said photoelectric detector to form a light spot at a position which is immovable with respect to the coordinate system;
• and
• correcting means for correcting the data produced by said distance measuring means, on the basis of the output produced by said photoelectric detector in response to receiving the light beam.

An exposure apparatus for printing a pattern of a mask on a wafer, said apparatus comprising:

• a mask chuck for holding the mask;
• a wafer chuck for holding the wafer;
• a wafer stage for moving said wafer chuck along a stage coordinate system;
• an alignment detecting optical system for projecting a light beam for alignment of the mask and the wafer;
• a photoelectric detector for receiving the light beam and for producing an output;
• a movable stage for moving said alignment detecting optical system so that said photoelectric detector receives the light beam from said alignment detecting optical system each time said alignment detecting optical system is moved to a different position by said movable stage;
• and
• control means for processing outputs of said photoelectric detector produced successively in response to receiving the light beam from said alignment detecting optical system being moved by said movable stage to different positions, to detect a change in position, caused by movement of said alignment detecting optical system, of a light spot formed by the light beam in terms of positional information related to the coordinate system of said wafer stage, and for controlling movement of said alignment detecting optical system by said movable stage based on the obtained position information.

An alignment method usable in an exposure apparatus for printing a pattern of a mask on a wafer placed on a wafer chuck movable along a predetermined coordinate system, said method comprising the steps of:

• providing a movable alignment detecting optical system for projecting a light beam for alignment of the mask and the wafer;
• providing a photoelectric detector integrally with the wafer chuck for receiving the light beam;
• moving the alignment detecting optical system to a first position;
• moving the wafer chuck along the predetermined coordinate system so that the photoelectric detector receives the light beam from the alignment detecting optical system;
• displacing the alignment detecting optical system to a next position;
• processing an output of the photoelectric detector produced in response to receiving the light beam from the alignment detecting optical system when the alignment detecting optical system is displaced and detecting a change in position of a light spot formed by the light beam resulting from the displacement of the alignment detecting optical system, in terms of position information related to the predetermined coordinate system;
• memorizing the obtained position information;
• moving and positioning the alignment detecting optical system to effect alignment of the mask and the wafer based on the memorized positional information;
• and
• aligning the mask and the wafer using the positioned alignment detecting optical system and using a light beam from the alignment detecting optical system.

In a method of manufacturing semiconductor devices by using an exposure apparatus for printing a pattern of a mask on a wafer, wherein the exposure apparatus includes a mask chuck for supporting the mask and being movable by a mask stage, a wafer chuck for supporting the wafer and being movable by a wafer stage, the improvement comprising the steps of:

• providing a light emitting element for emitting a light beam and being movable integrally with the mask chuck when the mask chuck is moved by the mask stage;
• providing a photoelectric detector movable integrally with the wafer chuck when the wafer chuck is moved by the wafer stage;
• moving the mask chuck through the mask stage successively to different positions;
• detecting, through the photoelectric detector, the light beam from the light emitting element each time the mask chuck is moved to a different position, such that the photoelectric detector produces a plurality of measurement data;
• detecting, on the basis of the plurality of measurement data, a change in position of the mask caused in response to movement of the mask chuck, in terms of positional information related to a stage coordinate system;
• and
• controlling, on the basis of the positional information, the movement of the wafer chuck through the wafer stage for printing the pattern of the mask on a zone of the wafer.

In a method of manufacturing semiconductor devices by using an exposure apparatus for printing a pattern of a mask on a wafer, wherein the exposure apparatus includes a mask stage for supporting and moving the mask and being supported by a frame member, a wafer chuck for supporting the wafer and being movable by a wafer stage, and laser interferometric distance measuring means including a mirror integrally movable with the wafer chuck when the wafer chuck is moved by the wafer stage, for measuring a change in position of the mirror with respect to a coordinate system of the wafer stage, the improvement comprising the steps of:

• providing a light emitting element in a fixed positional relation on the frame member;
• providing a photoelectric detector movable integrally with the wafer chuck when the wafer chuck is moved by the wafer stage;
• moving the wafer chuck through the wafer stage;
• causing the laser interferometric distance measuring means to measure a change in position of the mirror, during movement of the wafer chuck, through the wafer stage;
• detecting, through a photoelectric detector, a light beam emitted from the light emitting element;
• and
• correcting a measured value of the laser interferometric distance measuring means, on the basis of the detection of the light beam through the photoelectric detector, for correct printing of the pattern of the mask on a zone of the wafer.

In a method of manufacturing semiconductor devices by using an exposure apparatus for printing a pattern of a mask on a wafer, wherein the exposure apparatus includes an alignment detecting optical system for supplying a light beam and being movable by a movable stage, and a wafer chuck for supporting the wafer and being movable by a wafer stage, the improvement comprising the steps of:

• providing a photoelectric detector movable integrally with the wafer chuck when the wafer chuck is moved by the wafer stage;
• moving the alignment detecting optical system through the movable stage successively to different positions;
• detecting, through the photoelectric detector, the light beam from the alignment detecting optical system each time the alignment detecting optical system is moved to a different position, such that the photoelectric detector produces a plurality of measured values;
• detecting, on the basis of the produced plurality of measured values, a change in position of the light beam caused in response to movement of the alignment detecting optical system;
• and
• controlling, on the basis of the detection of the change in position of the light beam, movement of the alignment detecting optical system through the movable stage, for correct printing of the pattern of the mask on a zone of the wafer.