SOLUTION TO OPTICAL CONSTRAINT ON MICROTRUSS PROCESSING

• US 20110195361A1
• Filed: 02/05/2010
• Published: 08/11/2011
• Est. Priority Date: 02/05/2010
• Status: Active Grant

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: GM Global Technology Operations Incorporated (General Motors Company)
• Inventors: Rock, Jeffrey A.
• Granted Patent: US 8,367,307 B2
• Time in Patent Office: Days
• US Class Current: 430/322
• CPC Class Codes: G02B 2006/1219 Polymerisation
• CPC Class Codes: G03F 1/50 Mask blanks not covered by G03F1/20 - G03F1/34; Preparation thereof
• CPC Class Codes: G03F 7/201 characterised by an oblique exposure; characterised by the use of plural sources; characterised by the rotation of the optical device; characterised by a relative movement of the optical device, the light source, the sensitive system or the mask
• CPC Class Codes: G03F 7/2041 in the presence of a fluid, e.g. immersion; using fluid cooling means

Abstract

A system for fabricating a radiation-cured structure is provided. The system includes a radiation-sensitive material having a first refractive index; a mask formed from a mask material having a second refractive index; and a radiation source. The mask is disposed between the radiation source and the radiation-sensitive material, and has a plurality of substantially radiation transparent apertures. The radiation source is configured to generate radiation beams for at least one of initiating, polymerizing, and crosslinking the radiation-sensitive material. The system includes at least one of a) an at least one normalizing surface disposed between the radiation source and the mask, b) a refractive fluid having a third refractive index disposed between the radiation source and the mask, and c) the refractive fluid having the third refractive index disposed between the mask and the radiation-sensitive material. A method for fabricating the radiation-cured structure is also provided.

Claims

1. A system for fabricating a radiation-cured structure, comprising:

a radiation-sensitive material having a first refractive index;

a radiation source configured to generate a plurality of radiation beams for at least one of initiating, polymerizing, crosslinking, and dissociating the radiation-sensitive material; and

a mask disposed between the radiation-sensitive material and the radiation source, the mask having a plurality of substantially radiation transparent apertures, wherein the mask is formed from a mask material having a second refractive index, and at least one of a) an at least one normalizing surface is disposed between the radiation source and the mask, b) a refractive fluid having a third refractive index is disposed between the radiation source and the mask, and c) the refractive fluid having the third refractive index is disposed between the mask and the radiation-sensitive material.

2. The system of claim 1, further comprising a prism disposed adjacent the mask, the prism having the at least one normalizing surface.

3. The system of claim 2, wherein the prism, the radiation-sensitive material, and the mask are at least partially immersed in the refractive fluid.

4. The system of claim 1, wherein the mask has a plurality of facets providing the at least one normalizing surface.

5. The system of claim 1, wherein the third refractive index is intermediate the first refractive index and the second refractive index.

6. The system of claim 1, wherein the third refractive index is substantially the same as the first refractive index.

7. The system of claim 1, wherein the third refractive index is intermediate the refractive index of air and the second refractive index.

8. The system of claim 1, wherein the refractive fluid forms a layer between the mask and the radiation-sensitive material.

9. The system of claim 1, wherein the radiation-sensitive material and the mask are immersed in the refractive fluid.

10. The system of claim 9, wherein the radiation source is at least partially immersed in the refractive fluid.

11. The system of claim 10, wherein the radiation source has a lens with parallel sides substantially normal to the radiation beams, the lens at least partially immersed in the refractive fluid.

12. The system of claim 1, wherein the radiation-sensitive material is disposed on a substrate.

13. A system for fabricating a radiation-cured structure, comprising:

a radiation-sensitive material having a first refractive index;

a radiation source configured to generate radiation beams for at least one of initiating, polymerizing and crosslinking the radiation-sensitive material;

a mask disposed between the radiation-sensitive material and the radiation source, the mask formed from a mask material having a second refractive index and having a plurality of substantially radiation transparent apertures;

a refractive fluid having a third refractive index disposed between the mask and the radiation-sensitive material; and

a prism having at least one normalizing surface disposed between the radiation source and the mask.

14. A method for fabricating a radiation-cured structure, the comprising the steps of:

providing a radiation-sensitive material having a first refractive index, a mask having a plurality of substantially radiation transparent apertures, the mask formed from a material having a second refractive index, and a radiation source configured to generate radiation beams for at least one of initiating, polymerizing and crosslinking the radiation-sensitive material;

placing the mask between the radiation-sensitive material and the radiation source;

at least one of

a) disposing an at least one normalizing surface between the radiation source and the mask,

b) disposing a refractive fluid having a third refractive index between the radiation source and the mask, and

c) disposing the refractive fluid having the third refractive index between the mask and the radiation-sensitive material; and

exposing the radiation-sensitive materials to a plurality of radiation beams through the radiation transparent apertures in the mask, whereby the radiation-cured structure is formed.

15. The method of claim 14, wherein the step of disposing the refractive fluid between the radiation source and the mask includes the step of at least partially immersing the radiation source, the mask, and the radiation-sensitive material in the refractive fluid.

16. The method of claim 14, wherein the step of disposing the refracting fluid between the mask and the radiation-sensitive material includes the step of applying a layer of the refractive fluid to the radiation-sensitive material prior to placing the mask adjacent thereto.

17. The method of claim 14, wherein the step of disposing the at least one normalizing surface between the radiation source and the mask includes the step of placing a prism atop the mask.

18. The method of claim 14, wherein the step of disposing the at least one normalizing surface between the radiation source and the mask includes the step of providing the mask with a faceted surface.

19. The method of claim 14, further comprising the step of selecting the refractive fluid to have one of the third refractive index intermediate the first refractive index and the second refractive index, the third refractive index substantially the same as the first refractive index, and the third refractive index between the refractive index of air and the second refractive index.

20. The method of claim 14, further comprising the step of selecting the angle of the normalizing surface to allow the radiation beams to contact the normalizing surface at about normal to the normalizing surface, thereby minimizing a refraction of the radiation beams as they pass through the normalizing surface.