METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE AND A SEMICONDUCTOR DEVICE

• US 20150179883A1
• Filed: 12/22/2014
• Published: 06/25/2015
• Est. Priority Date: 12/30/2009
• Status: Active Grant

• Current Assignee: IMEC International
• Original Assignee: IMEC International
• Inventors: Cheng, Kai
• Granted Patent: US 10,461,220 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02587 Structure
• CPC Class Codes: H01L 21/0259 Microstructure
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 21/02639 Preparation of substrate for selective deposition
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• CPC Class Codes: H01L 2933/0058 relating to optical field-shaping elements
• CPC Class Codes: H01L 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 31/0236 Special surface textures
• CPC Class Codes: H01L 33/0062 for devices with an active region comprising only III-V compounds
• CPC Class Codes: H01L 33/0066 with a substrate not being a III-V compound
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A method of manufacturing a semiconductor device and the device resulted thereof is disclosed. In one aspect, the device has a heterogeneous layer stack of one or more III-V type materials, at least one transmission layer of the layer stack having a roughened or textured surface for enhancement of light transmission. The method includes (a) growing the transmission layer of a III-V type material, (b) providing a mask layer on the transmission layer, the mask layer leaving first portions of the transmission layer exposed, and (c) partially decomposing the first exposed portions of the transmission layer. Suitably redeposition occurs in a single step with decomposition, so as to obtain a textured surface based on crystal facets of a plurality of grown crystals. The resulting device has a light-emitting element. The transmission layer hereof is suitably present at the top side.

Claims

1. A method of fabricating a light-emitting semiconductor device, the method comprising:

providing a light-emitting layer stack;

forming a stop layer over the light-emitting layer stack;

forming a light-transmission layer on the stop layer, the light-transmission layer formed of a crystalline III-V semiconductor material that is optically transmissive to emission wavelengths of the light-emitting layer stack;

patterning a mask layer on the light-transmission layer such that portions of the light-transmission layer are exposed; and

thermally texturing the exposed portions of the light-transmission layer, wherein the stop layer has a decomposition temperature that is higher than that of the light-transmission layer such that texturing is prevented from extending into the stop layer.

2. The method of claim 1, wherein thermally texturing comprises subliming and redepositing atoms of the crystalline III-V material by heating to a temperature that is sufficient to sublime the crystalline III-V material while insufficient to sublime the stop layer.

3. The method of claim 2, wherein thermally texturing comprises subliming and redepositing simultaneously in a single process.

4. The method of claim 2, wherein the crystalline III-V semiconductor material is a nitride semiconductor and thermally texturing comprises providing nitrogen atoms of the nitride semiconductor by subliming and redepositing in an atmosphere containing nitrogen.

5. The method of claim 4, wherein the nitrogen content comprises ammonia.

6. The method of claim 4, wherein the atmosphere further comprises hydrogen.

7. The method of claim 1, wherein thermally texturing is carried out at atmospheric pressure and less than 1250°

C.

8. The method of claim 1, wherein the crystalline III-V semiconductor material is selected from the group consisting of GaN, InGaN, AlGaN, AlInGaN and InN.

9. The method of claim 8, wherein the crystalline III-V semiconductor material is GaN, and the stop layer is formed of AlN or AlGaN.

10. The method of claim 8, wherein the III-V semiconductor material is InGaN, and the stop layer is formed of one of AlN, AlGaN or GaN.

11. The method of claim 1, further comprising removing at least portions of patterned mask layer and replaced with at least one metal contact.

12. A method of fabricating a light-emitting semiconductor device, the method comprising:

forming a first nitride semiconductor layer on the light-emitting stack and a polycrystalline second nitride semiconductor layer on the first nitride semiconductor layer;

patterning a mask layer on the second nitride semiconductor layer to expose portions of the polycrystalline second semiconductor layer; and

selectively texturing exposed portions of the polycrystalline second nitride semiconductor layer to form a textured second nitride semiconductor layer comprising a plurality of crystals having a preferential crystal facet, wherein selectively texturing leaves the first nitride semiconductor layer untextured.

13. The method of claim 12, wherein selectively texturing includes heating at a temperature that is sufficient to sublime the polycrystalline second nitride layer while being insufficient to sublime the first nitride layer, such that texturing is stopped from extending into the first layer.

14. The method of claim 13, wherein selectively texturing includes heating in an ammonia environment.

15. The method of claim 14, wherein the polycrystalline second nitride semiconductor layer is formed of a material selected from the group consisting of GaN, InGaN, AlGaN, AlInGaN and InN.

16. The method of claim 15, wherein the textured second nitride semiconductor layer is in a phase having a hexagonal crystal structure such that the crystals have a pyramidal structure having triangular crystal facets.

17. The method of claim 15, further comprising providing an active layer stack including a light-emitting quantum well stack prior to forming the first nitride semiconductor layer thereon, wherein at least the polycrystalline second nitride semiconductor is optically transmissive in light wavelengths corresponding to an emission wavelength of the light-emitting quantum-well stack.

18. The method of claim 17, wherein selectively texturing includes heating at a temperature for a time duration sufficient to form the crystals that have an average size between about 300 nm and about 800 nm, such that a light transmissivity of the textured second nitride semiconductor is higher compared to a light transmissivity of the polycrystalline second nitride semiconductor.

19. The method of claim 17, further comprising doping the textured second nitride semiconductor layer and the first nitride semiconductor layer to form a p-doped region of the light emitting semiconductor device, and wherein the active layer stack further comprises an n-doped region.

20. The method of claim 13, wherein selectively texturing includes heating at a temperature between about 800°

C. and about 1150°

C.