Method for producing an optoelectronic semiconductor chip

• US 9,799,801 B2
• Filed: 05/14/2014
• Issued: 10/24/2017
• Est. Priority Date: 05/16/2013
• Status: Active Grant

• Current Assignee: OSRAM OLED GMBH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Schmid, Christian, Grosser, Julia, Floeter, Richard, Broell, Markus
• Primary Examiner(s): CHOUDHRY, MOHAMMAD M
• Application Number:
  US14/891,658
• Publication Number:
  US 20160104819A1
• Time in Patent Office: 1,259 Days
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/24 of the light emitting region, e.g. non-planar junction
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating

Abstract

A method for producing an optoelectronic semiconductor chip comprises the following steps: providing a substrate, depositing a sacrificial layer, depositing a functional semiconductor layer sequence, laterally patterning the functional semiconductor layer sequence, and oxidizing the sacrificial layer in a wet thermal oxidation process.

Claims

1. A method for producing an optoelectronic semiconductor chip having the following steps in the stated order:

providing a substrate;

depositing a buffer layer;

depositing a sacrificial layer;

depositing a functional semiconductor layer sequence, wherein the functional semiconductor layer sequence forms a light-emitting diode structure;

laterally patterning the functional semiconductor layer sequence so that a grid-like system of trenches is formed, the trenches extend through the semiconductor layer sequence in the opposite direction to a growth direction from a top of the functional semiconductor layer sequence remote from the substrate, the trenches split the functional semiconductor layer sequence and the sacrificial layer and end in the buffer layer, which acts as an etch stop layer, while not patterning the substrate;

oxidizing the sacrificial layer in a wet thermal oxidation process; and

separating the functional semiconductor layer sequence from the substrate, wherein the substrate remains as a contiguous uninterrupted layer.

2. The method according to claim 1, wherein the substrate comprises GaAs,

wherein the sacrificial layer comprises Al_xGa_1xAs,

wherein 0.8 <

×

<

1 and

wherein AlO_xH_y is formed during oxidation of the sacrificial layer.

3. The method according to claim 1, wherein the sacrificial layer comprises AlAs.

4. The method according to claim 1, wherein the sacrificial layer comprises Al_xGa_1-xAs, and

wherein 0.8 <

×

<

1.

5. The method according to claim 1, wherein AlO_xH_y is formed during oxidation of the sacrificial layer.

6. The method according to claim 1, wherein separating the functional semiconductor layer sequence from the substrate comprises removal by means of an etching solution of an oxide formed during oxidation of the sacrificial layer.

7. The method according to claim 1, wherein an etching solution is used which comprises hydrofluoric acid.

8. The method according to claim 1, wherein a shear force is exerted on the functional semiconductor layer sequence during separating the functional semiconductor layer sequence from the substrate.

9. The method according to claim 1, wherein the substrate is reused.

10. The method according to claim 1, wherein the following further step is carried out:

bonding of the functional semiconductor layer sequence to a carrier.

11. The method according to claim 10, wherein the bonding of the functional semiconductor layer sequence to the carrier takes place prior to oxidation of the sacrificial layer.

12. The method according to claim 10, wherein the bonding of the functional semiconductor layer sequence to the carrier takes place after oxidation of the sacrificial layer.

13. The method according to claim 10, wherein the carrier comprises silicon or germanium.

14. The method according to claim 1, wherein the substrate comprises GaAs.

15. A method for producing an optoelectronic semiconductor chip having the following steps:

providing a single substrate;

depositing a buffer layer;

depositing a sacrificial layer;

depositing a functional semiconductor layer sequence;

laterally patterning the functional semiconductor layer sequence so that a grid-like system of trenches is formed, the trenches extend through the semiconductor layer sequence in the opposite direction to a growth direction from a top of the functional semiconductor layer sequence remote from the substrate, the trenches split the functional semiconductor layer sequence and the sacrificial layer and end in the buffer layer, which acts as an etch stop layer, while not patterning the substrate;

providing a carrier on the functional semiconductor layer sequence on a side remote from the substrate; and

oxidizing the sacrificial layer in a wet thermal oxidation process,

wherein the substrate comprises GaAs,

wherein the sacrificial layer comprises Al_xGa_1-xAs,

wherein 0.8 <

×

<

1

wherein porous AlO_xH_y is formed during oxidation of the sacrificial layer, and

wherein during detachment of the functional semiconductor layer sequence from the single substrate, a shear force is exerted on the functional semiconductor layer sequence.

16. The method according to claim 15, wherein the steps of providing step, depositing the sacrificial layer, depositing the functional semiconductor layer sequence, laterally patterning and oxidizing are performed in that order.

17. A method for producing an optoelectronic semiconductor chip having the following steps:

providing a GaAs substrate;

depositing a sacrificial layer comprising Al_xGa_1-xAs, wherein 0.8 <

×

<

1;

depositing a functional semiconductor layer sequence which is a light-emitting diode structure;

laterally patterning the functional semiconductor layer sequence;

oxidizing the sacrificial layer in a wet thermal oxidation process so that porous AlO_xH_y is formed during oxidation of the sacrificial layer so that an oxidized sacrificial layer is yielded, the oxidized sacrificial layer is subsequently removed by means of an etching solution; and

separating the functional semiconductor layer sequence from the substrate, wherein the substrate is reused.