Correcting variations in the intensity of light within an illumination field without distorting the telecentricity of the light

An apparatus for changing an aggregate intensity of a light within an illumination field of a photolithography system, comprising:

• a blade structure configured to be positioned along an optical path of the photolithography system between an illumination system of the photolithography system and a reticle stage of the photolithography system so that, when said illumination system provides the light having the illumination field, said blade structure is substantially at a center of the illumination field and a first portion of the light within the illumination field impinges upon said blade structure, said blade structure is one of translucent to a wavelength of the light and opaque to said wavelength, said first portion of the light having a first area;
• and
• a first actuator coupled between a first portion of said blade structure and a frame of the photolithography system and configured to move at least said first portion of said blade structure in a first direction so that, when said illumination system provides the light having the illumination field, a second portion of the light within the illumination field impinges upon said blade structure, said second portion of the light having a second area, said second area different from said first area;
• wherein, when said illumination system provides the light having the illumination field, the illumination field is shaped as a rectangle;
• and
• wherein said blade structure has a blade structure length, a blade structure width, and a blade structure height and is oriented so that, when said illumination system provides the light having the illumination field, said blade structure length is substantially parallel to an illumination field length, said blade structure width is substantially parallel to an illumination field width, and said blade structure width substantially intersects a line that passes through a midpoint of said illumination field width, said line substantially parallel to said illumination field length.

An apparatus for changing an aggregate intensity of a light within an illumination field of a photolithography system, comprising:

• a blade structure configured to be positioned along an optical path of the photolithography system between an illumination system of the photolithography system and a reticle stage of the photolithography system so that, when said illumination system provides the light having the illumination field, said blade structure is substantially at a center of the illumination field and a first portion of the light within the illumination field impinges upon said blade structure, said blade structure is one of translucent to a wavelength of the light and opaque to said wavelength, said first portion of the light having a first area;
• and
• a first actuator coupled between a first portion of said blade structure and a frame of the photolithography system and configured to move at least said first portion of said blade structure in a first direction so that, when said illumination system provides the light having the illumination field, a second portion of the light within the illumination field impinges upon said blade structure, said second portion of the light having a second area, said second area different from said first area;
• wherein, when said illumination system provides the light having the illumination field, the illumination field is shaped as an annulus sector;
• and
• wherein said blade structure has a blade structure outer arc, a blade structure inner arc, a blade structure width, and a blade structure height and is oriented so that, when said illumination system provides the light having the illumination field, said blade structure outer arc is substantially similar to an illumination field outer arc, said blade structure inner arc is substantially similar to an illumination field inner arc, and said blade structure width substantially intersects an arc located midway between said illumination field outer arc and said illumination field inner arc.

An apparatus for changing an aggregate intensity of a light within an illumination field of a photolithography system, comprising:

• a blade structure configured to be positioned along an optical path of the photolithography system between an illumination system of the photolithography system and a reticle stage of the photolithography system so that, when said illumination system provides the light having the illumination field, said blade structure is substantially at a center of the illumination field and a first portion of the light within the illumination field impinges upon said blade structure, said blade structure is one of translucent to a wavelength of the light and opaque to said wavelength, said first portion of the light having a first area;
• and
• a first actuator coupled between a first portion of said blade structure and a frame of the photolithography system and configured to move at least said first portion of said blade structure in a first direction so that, when said illumination system provides the light having the illumination field, a second portion of the light within the illumination field impinges upon said blade structure, said second portion of the light having a second area, said second area different from said first area;
• wherein said first portion of said blade structure is a flap, said flap coupled to a second portion of said blade structure.

An apparatus for changing an aggregate intensity of a light within an illumination field of a photolithography system, comprising:

• a blade structure configured to be positioned along an optical path of the photolithography system between an illumination system of the photolithography system and a reticle stage of the photolithography system so that, when said illumination system provides the light having the illumination field, said blade structure is substantially at a center of the illumination field and a first portion of the light within the illumination field impinges upon said blade structure, said blade structure is one of translucent to a wavelength of the light and opaque to said wavelength, said first portion of the light having a first area defined by a first value;
• and
• a first actuator coupled between said blade structure and a frame of the photolithography system and configured to rotate said blade structure in a first direction so that, when said illumination system provides the light having the illumination field, a second portion of the light within the illumination field impinges upon said blade structure, said second portion of the light having a second area defined by a second value;
• wherein said first actuator is configured to rotate said at least said first portion of said blade structure, so that a difference of said second value subtracted from said first value is equal to any value within a continuous range.

A method for changing an aggregate intensity of a light within an illumination field of a photolithography system, comprising the steps of:

• (1) causing an illumination system of the photolithography system to provide the light having the illumination field;
• (2) positioning a blade structure along an optical path of the photolithography system between the illumination system and a reticle stage of the photolithography system and substantially at a center of the illumination field so that a first portion of the light within the illumination field impinges upon the blade structure, the blade structure is one of translucent to a wavelength of the light and opaque to the wavelength, the first portion of the light having a first area defined by a first value;
• and
• (3) moving at least a portion of the blade structure in a direction so that a second portion of the light within the illumination field impinges upon the blade structure, the second portion of the light having a second area, the second area different from the first area defined by a second value;
• wherein a difference of the second value subtracted from the first value is equal to any value within a continuous range.

A method for changing an aggregate intensity of a light within an illumination field of a photolithography system, comprising the steps of:

• (a) causing an illumination system of the photolithography system to provide the light having the illumination field;
• (b) positioning a blade structure along an optical path of the photolithography system between the illumination system and a reticle stage of the photolithography system and substantially at a center of the illumination field so that a first portion of the light within the illumination field impinges upon the blade structure, the blade structure is one of translucent to a wavelength of the light and opaque to the wavelength, the first portion of the light having a first area;
• (c) moving a first portion of a plurality of portions in a direction by a first distance so that a third portion of the light within the illumination field impinges upon the blade structure, the third portion of the light having a third area;
• and
• (d) moving a second portion of the plurality of portions in the direction by a second distance so that a fourth portion of the light within the illumination field impinges upon the blade structure, the fourth portion of the light having a fourth area, the second distance different from the first distance, the second area equal to a sum of the third area and the fourth area.