Large field of view projection optical system with aberration correctability

• US 20070195304A1
• Filed: 12/28/2006
• Published: 08/23/2007
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: ASML Holding NV, ASML Netherlands BV (ASML Holding NV)
• Original Assignee: ASML Holding NV, ASML Netherlands BV (ASML Holding NV)
• Inventors: Gui, Cheng-Qun, De Jager, Pieter, Harned, Robert
• Granted Patent: US 7,643,128 B2
• Time in Patent Office: Days
• US Class Current: 355/55
• CPC Class Codes: G02B 17/061 on-axis systems with at least one of the mirrors having a central aperture
• CPC Class Codes: G03B 27/52 Details
• CPC Class Codes: G03F 7/70233 Optical aspects of catoptric systems, i.e. comprising only reflective elements, e.g. extreme ultraviolet [EUV] projection systems
• CPC Class Codes: G03F 7/70308 Optical correction elements, filters or phase plates for manipulating imaging light, e.g. intensity, wavelength, polarisation, phase or image shift
• CPC Class Codes: G03F 7/706 Aberration measurement
• CPC Class Codes: G03F 7/70791 Large workpieces, e.g. glass substrates for flat panel displays or solar panels

Abstract

An exposure system for manufacturing flat panel displays (FPDs) includes a reticle stage adapted to support a reticle. A substrate stage is adapted to support a substrate. A reflective optical system is adapted to image the reticle onto the substrate. The reflective optical system includes a primary mirror including a first mirror and a second mirror, and a secondary mirror. The reflective optical system has sufficient degrees of freedom for both alignment and correction of third order aberrations when projecting an image of the reticle onto the substrate by reflections off the first mirror, the secondary mirror, and the second mirror.

Claims

1. A system, comprising:

a reticle;

a substrate; and

a reflective optical system configured to image the reticle onto the substrate, the reflective optical system comprising a primary mirror, the primary mirror including a first mirror and a second mirror, and a secondary mirror,

wherein the reflective optical system has ten (10) degrees of freedom for both alignment and correction of aberrations when projecting an image of the reticle onto the substrate by reflections off the first mirror, the secondary mirror, and the second mirror.

2. The exposure system of claim 1, wherein the first and second mirrors are concave, and the secondary mirror is convex.

3. The exposure system of claim 1, wherein the first, second or secondary mirrors are aspheric.

4. The exposure system of claim 1, wherein a radius of curvature of the secondary mirror is approximately half of a radii of curvature of the first and second mirrors.

5. The exposure system of claim 1, wherein centers of curvature of the secondary mirror and the first and second mirrors are nominally coincident.

6. The system of claim 1, wherein the centers of curvatures of the first and second mirrors are displaceable to provide fine magnification adjustment.

7. The system of claim 1, wherein the centers of curvatures of the first and second mirrors are displaceable to minimize aberrations resulting from magnification adjustment.

8. The system of claim 1, wherein the centers of curvatures of the first and second mirrors are displaceable to correct for any of residual optical manufacturing, coating, and mount induced errors.

9. The system of claim 1, wherein the first and second mirrors have the substantially the same curvatures.

10. The system of claim 1, further including at least one of a first parallel glass plate optically aligned between the reticle and the first mirror and a second parallel glass plate optically aligned between the substrate and the second mirror.

11. The system of claim 10, wherein either of the first and second glass plates have any of a spherical profile, an aspheric profile, a flat surface and a spherical surface, two spherical surfaces, a spherical surface and an aspherical surface, and two aspherical surfaces.

12. The system of claim 11, wherein any of the spherical and aspherical surfaces have concave or convex curvatures.

13. The system of claim 10, wherein either of the first or second parallel glass plates compensate for residual aberrations.

14. The system of claim 1, further including a meniscus lens near the first glass plate and between the first glass plate and the first concave mirror.

15. The system of claim 14, wherein the meniscus lens has an aspheric profile on one or both of its surfaces.

16. The system of claim 1, further including at least one of a nominally flat mirror with an aspheric profile positioned at an angle to the reticle and near the reticle and a nominally flat mirror with an aspheric profile positioned at an angle to the substrate and near the substrate.

17. The system of claim 16, wherein the aspheric profile is different in a vertical and horizontal axes.

18. The system of claim 1, further including at least one of a powered mirror with an aspheric profile positioned at an angle to the reticle and near the reticle and a powered mirror with an aspheric profile positioned at an angle to the substrate and near the substrate.

19. The system of claim 1, wherein the first and second mirrors having centers of curvature substantially coincident with the secondary mirror.

20. The system of claim 1, wherein the first and second mirrors are substantially symmetrically positioned with respect to a center of the secondary mirror.