Method for Fine Processing of Substrate, Method for Fabrication of Substrate, and Light Emitting Device

• US 20090114944A1
• Filed: 03/30/2007
• Published: 05/07/2009
• Est. Priority Date: 03/31/2006
• Status: Active Grant

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Kasahara, Kenji, Ono, Yoshinobu, Ueda, Kazumasa
• Granted Patent: US 7,645,625 B2
• Time in Patent Office: Days
• US Class Current: 257/103
• CPC Class Codes: H01L 21/30608 Anisotropic liquid etching H01L21/3063 takes precedence
• CPC Class Codes: H01L 21/308 using masks H01L21/3063, H01L21/3065 take precedence
• CPC Class Codes: H01L 2933/0083 Periodic patterns for optical field-shaping in or on the semiconductor body or semiconductor body package, e.g. photonic bandgap structures
• 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 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: Y10S 977/856 including etching/cutting

Abstract

The present invention provides a method for fine processing of a substrate, a method for fabrication of a substrate, and a light emitting device. In the method for fine processing of a substrate, after removing a single particle layer from the substrate having the single particle layer, a hole having an inner diameter smaller than a diameter of a particle and centering on a position on the substrate where each particle constructing the single particle layer has been placed is formed by etching. The method for fabrication of a substrateincludesthefollowingsteps (I) to (V) inthisorder:

• (I) forming the single particle layer by arranging the particles on the substrate;
• (II) reducing the diameter of each of the particles by etching the obtained substrate;
• (III) forming a thin film composed of a mask material on the obtained substrate;
• (IV) removing the particle from the substrate and forming a mask having a hole with an inner diameter equivalent to the diameter of the particle at the position where the individual particle has existed; and
• (V) forming a hole with a diameter equivalent to the inner diameter of the hole of the mask on the substrate below the hole of the mask by etching the substrate using the mask. The light emitting device is made of a nitride semiconductor and is formed with a fine hole on an entire surface or a partial region of a light extraction surface and/or an opposing surface.

Claims

1. A method for fine processing of a substrate which comprises, after removing a single particle layer from the substrate having the single particle layer, forming a hole having an inner diameter smaller than a diameter of a particle and centering on a position on the substrate where each particle constructing the single particle layer has been placed is formed by etching.

3. The method of claim 1 or 2, wherein the substrate in the step (I) is made of at least one selected from a semiconductor, a dielectric, a light-transmitting (conductive) material, and a metal.

4. The method of claim 3, wherein the semiconductor is made of a nitride.

5. The method of claim 3, wherein the substrate is made of the semiconductor and the light-transmitting (conductive) material.

6. The method of claim 3, wherein the light-transmitting material is made of ITO.

7. The method of claim 3, wherein the substrate is made of the semiconductor and the metal.

8. The method of claim 1 or 2, wherein each of the particles in the step (I) is made of an inorganic substance or a organic substance.

9. The method of claim 8, wherein the inorganic substance is made of at least one selected from an oxide, a nitride, a carbide, a boride, a sulfide, and a metal.

10. The method of claim 9, wherein the oxide is silica.

11. The method of claim 8, wherein the organic substance is a polymeric material.

12. The method of claim 11, wherein the polymeric material is polystyrene.

2. A method for fabrication of a substrate, comprising the following successive steps of (I) to (V):

(I) forming a single particle layer by arranging particles on the substrate;

(II) reducing a diameter of each of the particles by etching the obtained substrate;

(III) forming a thin film composed of a mask material on the obtained substrate;

(IV) removing the particle from the substrate and forming a mask having a hole with an inner diameter equivalent to the diameter of the particle at the position where the individual particle has existed; and

(V) forming a hole with the diameter equivalent to the inner diameter of the hole of the mask on the substrate below the hole of the mask by etching the substrate using the mask.

13. The method of claim 2, wherein the formation in the step (I) is performed by a advection and accumulation method, a dip-coating method, or a spin coating method.

14. The method of claim 2, wherein the etching in the step (II) is performed using a gas containing fluorine or a gas containing oxygen as an etching gas.

15. The method of claim 14, wherein the gas containing fluorine is at least one selected from CF₄, CHF₃, C₂H₂F₂, and C₂F₃Cl₃.

16. The method of claim 2, wherein the etching in the step (II) is performed by an anisotropic etching having a selectivity (=etching rate for the particle/etching rate for the substrate) of not less than 1.

17. The method of claim 2, wherein the etching in the step (II) is performed under a condition that the particle has the diameter corresponding to not less than 10% and not more than 95% of the particle diameter before the etching.

18. The method of claim 2, wherein the etching in the step (II) is performed under a condition that the particle is flattened.

19. The method of claim 2, wherein the mask material in the step (III) satisfies that a selectivity (=etching rate for the substrate/etching rate for the mask) of the etching in the step (V) is not less than 1.

20. The method of claim 2, wherein the mask material is Ni.

21. The method of claim 2, wherein the formation of the mask in the step (III) is performed by a vapor phase deposition method, a vacuum deposition method, an ion beam sputtering method, or a laser ablation method.

22. The method of claim 2, wherein the formation of the mask in the step (III) is performed by depositing the mask to a thickness of not more than 50% of a height of the particle having the reduced particle diameter at an incident angle of a particle of the mask material which is adjusted to be generally perpendicular to a surface of the substrate.

23. The method of claim 2, wherein the removal in the step (IV) is performed using an etching liquid which is excellent in particle solubility and poor in mask solubility.

24. The method of claim 2, wherein each of the particles in the step (I) is made of silica, the substrate is made of a nitride or ITO, and the etching in the step (II) is performed under a condition that an etching gas is a gas containing fluorine.

25. The method of claim 2, wherein each of the particles in the step (I) is made of a polymeric material, the substrate is made of a metal or ITO, and the etching in the step (II) is performed under a condition that an etching gas is a gas containing oxygen.

26. The method of claim 2, wherein each of the particles in the step (I) is made of silica, the mask material in the step (III) is Ni, and the etching in the step (V) is performed by using a wet process and an ultrasonic process in combination under conditions that an etching liquid is an alkaline liquid having a pH of not less than 12 and a temperature is not less than 50°

C.

27. The method of claim 2, wherein each of the particles in the step (I) is made of a polymeric material, the mask material in the step (III) is made of a metal, and the etching in the step (V) is performed under a condition that an etching liquid is an organic solvent.

28. A light emitting device which is made of a nitride semiconductor and is formed with a fine hole in an entire surface or a partial region of a light extraction surface and/or an opposing surface.