Optical system with improved durability for projection exposure apparatus and method for manufacturing optical system for projection exposure apparatus
AssigneeNikon Corporation
InventorsHiroki Jinbo, Seishi Fujiwara
Life of this patent
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Abstract
An optical system is provided in a projection exposure apparatus for processing an excimer laser beam. The optical system includes at least one optical member made of silica glass having a chlorine concentration of about 1 ppm or less, and at least one optical member made of silica glass having a chlorine concentration of about 1 ppm to about 200 ppm.
Claims4
An optical system for use in a projection exposure apparatus for processing an excimer laser beam, the optical system comprising:
- at least one optical member made of silica glass having a chlorine concentration of about 1 ppm or less;
- and
- at least one optical member made of silica glass having a fluorine content of about 0.01 wt % to about 0.5 wt %,
- wherein, both optical members are located in accordance with an energy density of light that each said optical member is to process.
An optical system for use in a projection exposure apparatus for processing an excimer laser beam, the optical system comprising:
- at least one optical member made of silica glass having a chlorine concentration of about 1 ppm to about 200 ppm;
- and,
- at least one optical member made of silica glass having a fluorine content of about 0.01 wt % to about 0.5 wt %,
- wherein both optical members are located in accordance with an energy density of light that each said optical member is to process.
An optical system for use in a projection exposure apparatus for processing an excimer laser beam, the optical system comprising:
- at least one optical member made of silica glass having a chlorine concentration of about 1 ppm or less;
- and,
- at least one optical member made of silica glass having a chlorine concentration of about 1 ppm to about 200 ppm;
- and,
- at least one optical member made of silica glass having a fluorine content of about 0.01 wt % to about 0.5 wt % each, wherein each optical member is located in accordance with an energy density of light that each said optical member is to process.
Dependencies are inferred from the claim text.