Semiconductor device having an InGaN layer

• US 8,343,782 B2
• Filed: 09/29/2010
• Issued: 01/01/2013
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: Soitec S.A.
• Original Assignee: Soitec S.A.
• Inventors: Letertre, Fabrice M.
• Primary Examiner(s): Loke, Steven
• Assistant Examiner(s): Yechuri, Sitaramarao S
• Application Number:
  US12/893,535
• Publication Number:
  US 20110134954A1
• Time in Patent Office: 825 Days
• Field of Search: 257/183, 257/189, 257/198, 257/200, 257/201, 257/613, 257/615, 257/618, 257/E33.001, 257/E33.011, 257/E33.002, 257/E33.023, 257/E33.025, 257/E33.026, 257/E33.028, 257/E33.03, 257/E33.033, 438/455, 438/458, 438/478, 438/481, 438/483, 438/502, 438/509
• US Class Current: 438/22
• CPC Class Codes: H01S 2301/173 The laser chip comprising special buffer layers, e.g. dislocation prevention or reduction
• CPC Class Codes: H01S 2304/12 Pendeo epitaxial lateral overgrowth [ELOG], e.g. for growing GaN based blue laser diodes
• CPC Class Codes: H01S 5/0215 Bonding to the substrate
• CPC Class Codes: H01S 5/0217 Removal of the substrate
• CPC Class Codes: H01S 5/183 having only vertical cavities, e.g. vertical cavity surface-emitting lasers [VCSEL]
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

The present invention relates to a method that involves providing a stack of a first substrate and a InGaN seed layer formed on the first substrate, growing an InGaN layer on the InGaN seed layer to obtain an InGaN-on-substrate structure, forming a first mirror layer overlaying the exposed surface of the grown InGaN layer, attaching a second substrate to the exposed surface of the mirror layer, detaching the first substrate from the InGaN seed layer and grown InGaN layer to expose a surface of the InGaN seed layer opposite the first mirror layer, and forming a second mirror layer overlaying the opposing surface of the InGaN seed layer.

Claims

1. A method for the manufacture of a vertical optoelectronic structure comprising:

providing a stack comprising a first substrate and a relaxed InGaN seed layer;

growing an InGaN layer on the relaxed InGaN seed layer to obtain an InGaN-on-substrate structure;

forming a first mirror layer overlaying a surface of the InGaN layer opposite the first substrate;

detaching the first substrate from the InGaN layer and the first mirror layer; and

forming a second mirror layer overlaying the InGaN layer;

wherein the stack is formed by;

growing the InGaN seed layer on a second substrate;

bonding the grown InGaN seed layer to a third substrate by a bonding layer comprising a borophosphosilicate glass;

relaxing the InGaN seed layer by heat treatment before or after removal of the second substrate; and

transferring the relaxed InGaN seed layer to the first substrate by means of a dielectric layer.

2. The method according to claim 1, wherein the InGaN layer is grown to a thickness within the range of 100 nm to 2000 nm.

3. The method according to claim 1, wherein the InGaN seed layer is grown to a thickness within the range of 5 nm to 500 nm.

4. The method according to claim 1, wherein forming the first mirror layer overlaying a surface of the InGaN layer opposite the first substrate further comprises

forming the first mirror layer on a fourth substrate;

and

bonding the InGaN-on-substrate structure to the first mirror layer formed on the fourth Substrate.

5. The method according to claim 4, wherein the first substrate and the InGaN seed layer are detached from the InGaN layer and first mirror layer to expose the InGaN layer, and

wherein the second mirror layer is formed directly overlaying the exposed InGaN layer.

6. The method according to claim 1, which further comprises:

bonding a fourth substrate to the first mirror layer overlaying the surface of the InGaN layer.

7. The method according to claim 6, wherein the InGaN seed layer is removed by etching or polishing.

8. The method according to claim 6, wherein the first substrate is detached from the InGaN layer and first mirror layer to expose the InGaN seed layer, and

wherein the second mirror layer is formed directly overlaying the exposed InGaN seed layer.

9. The method according to claim 1, which further comprises:

bonding a fourth substrate to the first mirror layer;

exposing a surface of the InGaN seed layer; and

forming the second mirror layer on the exposed surface of the InGaN seed layer.

10. The method according to claim 9, wherein the first mirror layer and the second mirror layer comprise all-oxide distributed Bragg reflectors or III-nitride distributed Bragg reflectors.

11. The method according to claim 1, wherein the InGaN seed layer on the first substrate has a thickness defined by an ion implantation produced weakened region.

12. The method according to claim 1, wherein the second substrate is a template or reusable substrate that includes a GaN layer.

13. The method according to claim 12, wherein the GaN layer of the template or substrate has a dislocation density of less than 5×

10⁸ cm<sup>−

2</sup>.

14. The method according to claim 1, wherein the stack further comprises a dielectric layer between the first substrate and the InGaN seed laver, and wherein the dielectric layer includes an electromagnetic absorbing layer disposed therein to promote subsequent detachment of the first substrate by absorption of electromagnetic radiation.

15. The method of claim 1 which results in a structure comprising:

the InGaN seed layer;

the InGaN layer on the InGaN seed layer; and

the two mirror layers on opposing sides of and sandwiching the InGaN seed layer and InGaN layer;

wherein the method further comprises using this structure as or in a vertical optoelectronic device.

16. The method of claim 15 wherein the first and second mirror layers are distributed Bragg reflectors.

17. The method of claim 15 which further comprises providing a second substrate adjacent one of the mirror layers.

18. The method according to claim 1 wherein the InGaN-on-substrate structure is subject to heat treatment in order to relax the InGaN seed layer.