Exposure method and apparatus

An exposure apparatus comprising:

• a projection optical system for projecting a predetermined pattern formed on a mask onto an object to be exposed;
• an illumination optical system for varying an effective light source distribution for illuminating the mask;
• and
• a controller for forming the effective light source shape based on a combination of a Zernike sensitivity coefficient that represents sensitivity of a change of image quality of the predetermined pattern to a change of a Zernike coefficient, when wave front aberration in the projection optical system is developed into a Zernike polynomial for plural point light sources that divide an effective light source area for illuminating the mask by intensity of each point light source.

A program that enables a computer to execute an exposure method for projecting, through a projection optical system, a predetermined pattern formed on a mask onto an object to be exposed,

• wherein said exposure method includes the steps of:
• dividing an effective light source area for illuminating the mask into plural point light sources;
• calculating a Zernike sensitivity coefficient that represents sensitivity of a change of image quality of the predetermined pattern to a change of a Zernike coefficient, when wave front aberration in the projection optical system is developed into a Zernike polynomial for all divided point light sources;
• determining an effective light source distribution based on a combination of Zernike sensitivity coefficient of all divided point light sources;
• and
• forming the effective light source distribution by intensity of each point light source.

A device fabrication method comprising the steps of:

• exposing an object using an exposure apparatus;
• and
• performing a predetermined process for the object exposed, wherein the exposure apparatus includes:
• (i) a projection optical system for projecting a predetermined pattern formed on a mask onto an object to be exposed;
• (ii) an illumination optical system for varying an effective light source distribution for illuminating the mask;
• and
• (iii) a controller for forming the effective light source shape based on a combination of a Zernike sensitivity coefficient that represents sensitivity of a change of image quality of the predetermined pattern to a change of a Zernike coefficient, when wave front aberration in the projection optical system is developed into a Zernike polynomial for plural point light sources that divide an effective light source area for illuminating the mask by intensity of each point light source.