Optical element manufacturing system, an illumination system, and an exposure apparatus

• US 6,301,001 B1
• Filed: 03/03/2000
• Issued: 10/09/2001
• Est. Priority Date: 10/03/1996
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Unno, Yasuyuki
• Primary Examiner(s): Adams, Russell
• Assistant Examiner(s): FULLER, RODNEY EVAN
• Application Number:
  US09/518,103
• Time in Patent Office: 585 Days
• Field of Search: 355/67, 356/399, 356/401, 430/30, 430/321, 430/394, 430/22, 430/396, 359/565, 359/575
• US Class Current: 355/67
• CPC Class Codes: G02B 5/1857 using exposure or etching means, e.g. holography, photolithography, exposure to electron or ion beams
• CPC Class Codes: G02B 5/1876 Diffractive Fresnel lenses; Zone plates; Kinoforms G02B5/1842, G02B5/1847 take precedence; optical systems having diffractive correction means G02B27/0037; Fresnel lenses operating by refraction G02B3/08
• CPC Class Codes: G02B 5/188 Plurality of such optical elements formed in or on a supporting substrate
• CPC Class Codes: G03F 7/70633 Overlay, i.e. relative alignment between patterns printed by separate exposures in different layers, or in the same layer in multiple exposures or stitching
• CPC Class Codes: G03F 9/70 for microlithography measuring printed patterns for monitoring overlay G03F7/70633 or focus G03F7/70641; projection system adjustment G03F7/70258; position control G03F7/70775

Abstract

An optical element manufacturing method includes a first process for forming a mask pattern on a substrate, and a second process for forming a step-like structure on the substrate by use of the mask pattern, wherein the first and second processes are repeated N times, and wherein, before execution of the (k)th time second process where 2≦k≦N, there is a process for determining a relative alignment error between a mask pattern as formed through the (k)th time first process and a mask pattern as formed through the (k−1)th time first process, and wherein the height of the step-like structure to be defined by the (k)th time second process is determined in accordance with the alignment error.

Claims

1. An optical element manufacturing system, comprising:

means for forming a mask pattern on a substrate;

means for determining a relative alignment error between a mask pattern just having been formed and a mask pattern previously formed; and

means for forming a step-like structure on the substrate by use of the mask pattern just having been formed, wherein the height of the step-like structure to be formed through said step-like structure forming means is determined in accordance with the determined alignment error determined by said determining means.

2. An illumination system, comprising:

a light directing device configured to direct illumination light supplied from a light source to an object to be illuminated,

said light directing device including an optical element,

said optical element having been manufactured through a procedure which includes a first process for forming a mask pattern on a substrate, and a second process for forming a step-like structure on the substrate by use of the mask pattern, wherein the first and second processes are repeated N times, and wherein, before execution of the (k)th time second process where 2≦

k≦

N, the relative alignment error between a mask pattern as formed through the (k)th time first process and a mask pattern as formed through the (k−

1)th time first process is detected, and wherein the height of the step-like structure to be defined by the (k)th time second process is determined in accordance with the detected alignment error,

wherein said optical element has a step-like structure having a detected-alignment-error-determined height.

3. An illumination system, comprising:

a light directing device configured to direct illumination light supplied from a light source to an object to be illuminated,

said light directing device including an optical element,

said optical element having been manufactured through a procedure which includes a first process for forming a first mask pattern on a substrate, a second process for forming a step-like structure on the substrate by use of the first mask pattern, a third process for forming a second mask pattern on the substrate, a fourth process for detecting a relative alignment error between the first and second mask patterns, and a fifth process for forming a step-like structure on the substrate by use of the second mask pattern, wherein the height of the step-like structure to be formed through the fifth process is determined in accordance with the detected alignment error detected by the fourth process,

wherein said optical element has a step-like structure having a detected-alignment-error-determined height.

4. An illumination system comprising:

a light directing device configured to direct illumination light supplied from a light source to an object to be illuminated,

said light directing device including an optical element,

said optical element having been manufactured through a procedure which includes a first process for forming a mask pattern on a substrate, a second process for detecting a relative alignment error between a mask pattern just having been formed and a mask pattern previously formed, and a third process for forming a step-like structure on the substrate by use of the mask pattern just having been formed, wherein the height of the step-like structure to be formed through the third process is determined in accordance with the detected alignment error,

wherein said optical element has a step-like structure having a detected-alignment-error-determined height.

5. An exposure apparatus, comprising:

illumination means for directing illumination light supplied from a light source to a reticle; and

projection means for projecting an image of the reticle on to a wafer;

wherein at least one of said illumination means and said projection means includes an optical element,

said optical element having been manufactured through a procedure which includes a first process for forming a mask pattern on a substrate, and a second process for forming a step-like structure on the substrate by use of the mask pattern, wherein the first and second processes are repeated N times, and wherein, before execution of the (k)th time second process where 2≦

k≦

N, a relative alignment error between a mask pattern as formed through the (k)th time first process and a mask pattern as formed through the (k−

1)th time first process is detected, and wherein the height of the step-like structure to be defined by the (k)th time second process is determined in accordance with the detected alignment error,

wherein said optical element has a step-like structure having a detected-alignment-error-determined height.

6. An exposure apparatus, comprising:

illumination means for directing illumination light supplied from a light source to a reticle; and

projection means for projecting an image of the reticle on to a wafer;

wherein at least one of said illumination means and said projection means includes an optical element,

said optical element having been manufactured through a procedure which includes a first process for forming a first mask pattern on a substrate, a second process for forming a step-like structure on the substrate by use of the first mask pattern, a third process for forming a second mask pattern on the substrate, a fourth process for detecting a relative alignment error between the first and second mask patterns, and a fifth process for forming a step-like structure on the substrate by use of the second mask pattern, wherein the height of the step-like structure to be formed through the fifth process is determined in accordance with the detected alignment error,

wherein said optical element has a step-like structure having a detected-alignment-error-determined height.

7. An exposure apparatus, comprising:

illumination means for directing illumination light supplied from a light source to a reticle; and

projection means for projecting an image of the reticle on to a wafer;

wherein at least one of said illumination means and said projection means includes an optical element,

said optical element having been manufactured through a procedure which includes a first process for forming a mask pattern on a substrate, a second process for detecting a relative alignment error between a mask pattern just having been formed and a mask pattern previously formed, and a third process for forming a step-like structure on the substrate by use of the mask pattern just having been formed, wherein the height of the step-like structure to be formed through the third process is determined in accordance with the detected alignment error,

wherein said optical element has a step-like structure having a detected-alignment-error-determined height.