Illumination optical system and exposure apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorKenichiro Mori
Life of this patent
Estimating the term…
Abstract
An illumination optical system for illuminating a target surface using light from a light source, includes a sensor for detecting a light intensity of the light, a light splitter for splitting part of the light, and an optical element, arranged between the light source and the light splitter, for transmitting the light, and for reflecting the part of the light that has been split by the light splitter, towards the sensor.
Claims22
An illumination optical system for illuminating a target surface using light from a light source, said illumination optical system comprising:
- a light splitter for splitting part of the light;
- an optical element, arranged between the light source and said light splitter, for transmitting the light and for reflecting the part of the light that has been split by said light splitter;
- and
- a sensor for detecting a light intensity of the light reflected by the optical element.
An illumination optical system for illuminating a target surface using light from a light source, said illumination optical system comprising:
- a light splitter for splitting part of the light;
- and
- an optical element arranged between the light source and the light splitter, said optical element having a reflective surface that has a reflectance of 2% or higher and reflects the part of the light that has been split by said light splitter and;
- a sensor for detecting a light intensity of the light reflected by the optical element.
An exposure apparatus comprising:
- a projection optical system for projecting light from a light source that passes a pattern onto an object to be exposed;
- a light splitter arranged between the light source and the pattern, said light splitter splitting part of the light that reaches the object;
- an optical element arranged between the light source and the light splitter, said optical element reflecting part of the light that has been split by said light splitter, towards said sensor;
- and
- a sensor for detecting the light split by the light splitter and reflected by the optical element, and for monitoring an exposure dose on the object.
Dependencies are inferred from the claim text.