Exposure method and exposure apparatus

An optical scanner, comprising:

• projection optics;
• a wafer stage on which a wafer coated with a photo resist layer is placed;
• a focus-leveling sensor for detecting a height and a tilt of the wafer;
• and
• a controller for controlling the wafer stage and the focus-leveling sensor, and including a processor and a memory storing a program, wherein:
• the program, when executed by the processor, causes the controller to perform:
• obtaining a wafer exposure map, which defines a matrix of exposure fields per wafer and a matrix of sub-areas within one exposure field;
• defining, based on the wafer exposure map, valid sub-areas when an entirety of a given sub-area is within a first circular perimeter, the valid sub-areas including at least one first sub-area an entirety of which is within a second circular perimeter having a smaller diameter than the first circular perimeter, and at least one second sub-area which overlaps the second circular perimeter, and defining, based on the wafer exposure map, invalid sub-areas each of which overlaps the first circular perimeter;
• and
• exposing one exposure field of the matrix of exposure field, the exposing one exposure field comprises:
• measuring focus-leveling data by using the focus-leveling sensor providing a plurality of laser beams arranged in an X direction, while moving the wafer in a Y direction;
• and
• exposing a part of a scanning area by an exposing light having a slit shape extending in the X direction by using one or more measured focus-leveling data, while moving the wafer in the Y direction, and
• the measured focus-leveling data corresponding to valid sub-areas are used in the exposing to control focus-leveling, and the measured focus-leveling data corresponding to the invalid sub-areas are not used in the exposing.

A method executed in an exposure apparatus, comprising:

• obtaining a wafer exposure map, which defines a matrix of exposure fields per wafer and a matrix of sub-areas within one exposure field;
• defining a focus control effective region and a focus control exclusion region, based on the wafer exposure map;
• exposing one exposure field of the matrix of exposure field, wherein:
• a boundary between the focus control effective region and the focus control exclusion region is across at least one exposure field,
• the exposing one exposure field comprises:
• measuring focus-leveling data by using a focus-leveling sensor providing a plurality of laser beams arranged in an X direction, while moving the wafer in a Y direction;
• and
• exposing a part of a scanning area by an exposing light having a slit shape extending in the X direction by using one or more measured focus-leveling data, while moving the wafer in the Y direction, and
• the measured focus-leveling data corresponding to sub-areas within the focus control effective region are used in the exposing to control focus-leveling, and the measured focus-leveling data corresponding to sub-areas within the focus control exclusion region are not used in the exposing.