Method of manufacturing surface textured high-efficiency radiating devices and devices obtained therefrom

• US 6,812,161 B2
• Filed: 10/16/2002
• Issued: 11/02/2004
• Est. Priority Date: 07/28/1998
• Status: Expired due to Term

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: IMEC International
• Inventors: Heremans, Paul, Kuijk, Maarten, Windisch, Reiner, Borghs, Gustaaf
• Primary Examiner(s): Smith, Matthew
• Assistant Examiner(s): Yevsikov, Victor V
• Application Number:
  US10/272,690
• Publication Number:
  US 20030075723A1
• Time in Patent Office: 748 Days
• Field of Search: 430/5, 430/30, 378/35, 438/782, 438/778
• US Class Current: 438/782
• CPC Class Codes: G02B 6/4224 using visual alignment markings, e.g. index methods
• CPC Class Codes: G02B 6/4249 comprising arrays of active devices and fibres
• CPC Class Codes: G02B 6/4292 the light guide being disconnectable from the opto-electronic element, e.g. mutually self aligning arrangements
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 33/025 Physical imperfections, e.g. particular concentration or distribution of impurities
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/30 containing only elements of Group III and Group V of the Periodic Table
• CPC Class Codes: H01L 33/385 the electrode extending at least partially onto a side surface of the semiconductor body
• CPC Class Codes: H01L 33/405 Reflective materials
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector

Abstract

A method of texturing a surface of a substrate, includes providing a substrate, and distributing separate particles of an overlayer material in a substantially random pattern over at least a part of a surface of the substrate. The substantially random pattern of separate particles is used as a mask for a subsequent processing of the substrate.

Claims

1. A method of texturing a surface of a substrate, comprising:

providing a substrate;

distributing separate particles of an overlayer material in a substantially random pattern over at least a part of a surface of the substrate;

subjecting the distributed separate particles to a predetermined environment, which reduces the size of the particles; and

using the substantially random pattern of separate particles as a mask for a subsequent processing of the substrate.

2. The method of claim 1, wherein the size reduction of the particles results in coverage of about 50% of the surface.

3. The method of claim 2, wherein the particles are applied in an essentially two-dimensional monolayer.

4. The method of claim 3, further comprising applying a sacrificial layer over at least the part of the surface of the substrate, and transferring the pattern to the sacrificial layer.

5. The method of claim 4, wherein said sacrificial layer is applied prior to distributing said separate particles.

6. The method of claim 4, wherein said sacrificial layer includes a photosensitive material.

7. The method of claim 6, wherein said photosensitive material is of a positive type, and wherein the subsequent processing of the substrate includes forming islands of photosensitive material aligned to the particles.

8. The method of claim 6, wherein said photosensitive material is of a negative type, and wherein the subsequent processing of the substrate includes forming holes in the photosensitive material aligned to the particles.

9. The method of claim 1, wherein the subsequent processing comprises transferring the pattern to the surface;

and wherein the transfer results in a roughening of the surface, the surface thereby being rendered diffusive for electromagnetic radiation impinging on the surface.

10. A method of texturing a surface of a substrate, comprising:

providing a substrate;

applying a layer of photosensitive material over at least a part of a surface of the substrate;

illuminating the layer of photosensitive material in accordance with a substantially random pattern of predetermined separate features, wherein illuminating the layer of photosensitive material comprises forming an optical mask containing the substantially random pattern of predetermined separate features and illuminating the layer of photosensitive material through the optical mask;

developing the layer of photosensitive material; and

using the developed layer as a mask for subsequent processing of the substrate, wherein forming the optical mask comprises;

providing an optical substrate;

distributing particles of an overlayer material in the substantially random pattern over at least a part of a surface of the optical substrate; and

reducing the size of said particles.

11. The method of claim 10, wherein illuminating the layer of photosensitive material comprises applying a beam of electromagnetic radiation upon the layer of photosensitive material in a substantially random pattern.

12. A method of texturing a surface of a substrate, comprising:

applying an overlayer material to at least a part of a surface of a substrate to form a first masking layer having a pattern of substantially randomly distributed predetermined features, wherein the predetermined features include islands of overlayer material; and

using the first masking layer as a mask for subsequent processing of said substrate.

13. The method of claim 12, wherein said subsequent processing includes etching pillars in said substrate.

14. The method of claim 12, wherein applying the overlayer material includes applying particles of a predetermined size and reducing the size of the particles, wherein the particles reduced in size form said predetermined features.

15. The method of claim 12, wherein applying the overlayer material includes applying a layer of photosensitive material covering said part of said surface, illuminating said layer, and developing said layer to form said predetermined features.

16. A method of texturing a surface of a substrate, comprising:

providing a substrate;

distributing particles of an overlayer material in a substantially random pattern over at least a part of a surface of the substrate;

separating said particles, wherein separating said particles comprises reducing a size of said particles; and

using the substantially random pattern of said separated particles as a mask for a subsequent processing of the substrate.

17. The method of claim 16, further comprising creating at least one device for emitting radiation at a predetermined wavelength in the substrate.

18. The method of claim 17, wherein said at least one device has a cavity, and wherein said surface is at least a part of edges of said cavity.

19. The method of claim 16, further comprising creating an array of devices for emitting radiation at a predetermined wavelength in said material, wherein edge patterns on edges of at least two devices of said array are substantially identical.

20. The method of claim 19, wherein the size reduction of the particles is in a range of about 50% to about 200% of the predetermined wavelength in the substrate.

21. A method of texturing a surface of a substrate, comprising:

providing a substrate;

distributing particles of an overlayer material in a substantially random pattern over at least a part of a surface of the substrate to form a layer, the layer comprising particles which touch one another, thereby forming groups of particles;

subjecting the layer to a predetermined environment such that the particles of the groups of particles are separate and no longer touch one another; and

using the substantially random pattern of separate particles as a mask for a subsequent processing of the substrate.