Method of manufacturing a semiconductor device and a semiconductor device

• US 10,461,220 B2
• Filed: 12/22/2014
• Issued: 10/29/2019
• Est. Priority Date: 12/30/2009
• Status: Active Grant

• Current Assignee: IMEC International
• Original Assignee: IMEC International
• Inventors: Cheng, Kai
• Primary Examiner(s): Bell, Lauren R
• Application Number:
  US14/579,889
• Publication Number:
  US 20150179883A1
• Time in Patent Office: 1,772 Days
• Field of Search: 257 13, 257E33008, 257E33074, 438 22, 438 29
• 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;

thermally texturing in an atmosphere comprising molecular hydrogen (H₂) and ammonia, the thermally texturing comprises decomposing the light-transmission layer at the exposed portions into chemical constituents of the III-V semiconductor material and redepositing to form a plurality of crystals of the III-V semiconductor material having triangular crystal facets; and

stopping the thermal texturing by locally stopping the decomposing and redepositing at an interface formed by the stop layer and 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 the decomposing comprises heating to a temperature that is sufficient to decompose the crystalline III-V material while insufficient to decompose the stop layer.

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

4. The method of claim 2, wherein the III-V semiconductor material is a nitride semiconductor and the thermally texturing comprises providing nitrogen atoms of the nitride semiconductor at least in part by the decomposing and the redepositing in the atmosphere comprising the molecular hydrogen (H₂) and ammonia.

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

C.

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

7. The method of claim 6, wherein the III-V semiconductor material is GaN, and the stop layer is formed of AlN or AlGaN.

8. The method of claim 6, wherein the III-V semiconductor material is InGaN, and the stop layer is formed of one of AlN, AlGaN or GaN.

9. The method of claim 1, further comprising, after patterning the mask layer, removing at least portions of the patterned mask layer and replacing with at least one metal contact.

10. The method of claim 1, wherein providing the light-emitting layer stack comprises forming a light emitting element interposed between a p-type device layer and a n-type device layer by growing one of the p-type device layer or the n-type device layer on a silicon substrate having (111) crystal orientation.

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

providing a light-emitting layer stack;

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

selectively texturing in an atmosphere comprising molecular hydrogen (H₂) and ammonia, the selectively texturing comprises decomposing the polycrystalline second nitride semiconductor layer at the exposed portions into chemical constituents of the polycrystalline second nitride semiconductor layer and redepositing to form a textured second nitride semiconductor layer comprising a plurality of crystals of the second nitride semiconductor having triangular crystal facets; and

stopping the selective texturing by locally stopping the decomposing and the redepositing at an interface formed by the stop layer and the polycrystalline second nitride semiconductor layer,

wherein the selectively texturing leaves the first nitride semiconductor layer untextured.

12. The method of claim 11, wherein the selectively texturing includes heating at a temperature that is sufficient to decompose the polycrystalline second nitride layer while being insufficient to decompose the first nitride layer, such that texturing is stopped from extending into the first layer.

13. The method of claim 12, wherein the selectively texturing includes heating at a temperature between about 800°

C. and about 1150°

C.

14. The method of claim 11, wherein the polycrystalline second nitride semiconductor layer is formed of a material selected from the group consisting of GaN, InGaN, AlGaN, AlInGaN and InN.

15. The method of claim 14, 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 the triangular crystal facets.

16. The method of claim 14, wherein providing the light-emitting layer stack comprises providing 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.

17. The method of claim 16, wherein the selectively texturing includes heating at a temperature for a time duration sufficient to form the plurality of crystals having 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.

18. The method of claim 16, 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.