SEMICONDUCTOR DEVICE HAVING AN InGaN LAYER

• US 20110134954A1
• Filed: 09/29/2010
• Published: 06/09/2011
• Est. Priority Date: 12/07/2009
• Status: Active Grant

• Current Assignee: Soitec S.A.
• Original Assignee: Soitec S.A.
• Inventors: Letertre, Fabrice M.
• Granted Patent: US 8,343,782 B2
• Time in Patent Office: Days
• US Class Current: 372/50.11
• 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 an InGaN seed layer formed thereon;

growing an InGaN layer on the 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 and mirror layers to expose the InGaN seed layer; and

forming a second mirror layer overlaying the exposed InGaN seed 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 the first mirror layer is provided on a second substrate, and the method further comprises:

bonding the InGaN-on-substrate structure to the first mirror layer formed on the second substrate; and

removing the stack of the first substrate and the InGaN seed layer to expose the opposing surface of the grown InGaN layer.

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

bonding a second substrate to the first mirror layer overlaying the surface of the InGaN layer; and

removing the stack of the first substrate and the InGaN seed layer to expose the opposing surface of the grown InGaN layer.

6. The method according to claim 5, wherein the InGaN seed layer is removed by etching or polishing.

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

bonding a second 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.

8. The method according to claim 7, wherein the first mirror layer and the second mirror layer comprise all-oxide distributed Bragg reflectors or III-nitride distributed Bragg reflectors.

9. The method according to claim 1, which further comprises providing the stack with a dielectric layer between the first substrate and the InGaN seed layer.

10. The method according to claim 9, wherein the stack is formed by:

growing the InGaN seed layer on a third substrate;

bonding the grown InGaN seed layer to a fourth substrate by a bonding layer;

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

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

11. The method according to claim 10, 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 stack is formed by:

growing the InGaN seed layer on a third substrate;

bonding the grown InGaN seed layer to a fourth substrate by a bonding layer;

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

transferring the relaxed InGaN seed layer to the first substrate.

13. The method according to claim 12, wherein the bonding layer is a borophosphosilicate glass layer or an SiO₂—

compound layer comprising boron or phosphorous.

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

15. The method according to claim 14, wherein the GaN layer of the template or substrate has a dislocation density of less than 5×

10⁸ cm<sup>−

2</sup>.

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

providing a stack comprising a first substrate and an InGaN seed layer formed thereon;

forming a dielectric bonding layer between the first substrate and the InGaN seed layer;

growing an InGaN layer on the 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 and mirror layers to expose the InGaN seed layer; and

forming a second mirror layer overlaying the exposed InGaN seed layer;

wherein the dielectric bonding layer includes an electromagnetic absorbing layer disposed therein to promote subsequent detachment of the substrate by absorption of electromagnetic radiation.

17. A vertical optoelectronic structure comprising:

an InGaN seed layer;

an active InGaN layer grown on the InGaN seed layer; and

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

18. The structure of claim 17, further comprising a substrate adjacent the first mirror layer attached and adjacent to the substrate.

19. The structure of claim 18, wherein the first mirror layer and second mirror layer are distributed Bragg reflectors.

20. The structure of claim 17, which further comprises a dielectric layer between the first substrate and the InGaN seed layer.