Method for producing a thin-film semiconductor body and thin-film semiconductor body

• US 9,202,967 B2
• Filed: 02/28/2012
• Issued: 12/01/2015
• Est. Priority Date: 03/03/2011
• Status: Active Grant

• Current Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Original Assignee: Osram Opto Semiconductors GmbH (Ams-Osram AG)
• Inventors: Leirer, Christian, Vogl, Anton, Biebersdorf, Andreas, Butendeich, Rainer, Rumbolz, Christian
• Primary Examiner(s): Tran, Minh-Loan
• Assistant Examiner(s): KHAN, FARID H
• Application Number:
  US14/002,487
• Publication Number:
  US 20140061694A1
• Time in Patent Office: 1,372 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 21/0237 Materials
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02494 Structure
• CPC Class Codes: H01L 21/02502 consisting of two layers
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/02664 Aftertreatments planarisation in general H01L21/304
• 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 33/007 comprising nitride compounds
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers

Abstract

A method for producing a thin-film semiconductor body is provided. A growth substrate is provided. A semiconductor layer with funnel-shaped and/or inverted pyramid-shaped recesses is epitaxially grown onto the growth substrate. The recesses are filled with a semiconductor material in such a way that pyramid-shaped outcoupling structures arise. A semiconductor layer sequence with an active layer is applied on the outcoupled structures. The active layer is suitable for generating electromagnetic radiation. A carrier is applied onto the semiconductor layer sequence. At least the semiconductor layer with the funnel-shaped and/or inverted pyramid-shaped recesses is detached, such that the pyramid-shaped outcoupling structures are configured as projections on a radiation exit face of the thin-film semiconductor body.

Claims

1. A method for producing a thin-film semiconductor body, the method comprising:

epitaxially growing a semiconductor layer with funnel-shaped and/or inverted pyramid-shaped recesses onto a growth substrate at a growth temperature of less than or equal to 850°

C., wherein the funnel-shaped and/or inverted pyramid-shaped recesses are V-defects or V-pits;

filling the recesses with a semiconductor material in such a way that pyramid-shaped outcoupling structures arise;

applying a semiconductor layer sequence with an active layer, which is suitable for generating electromagnetic radiation, on the outcoupling structures;

applying a carrier onto the semiconductor layer sequence; and

detaching the semiconductor layer with the funnel-shaped and/or inverted pyramid-shaped recesses, such that the pyramid-shaped outcoupling structures are configured as projections on a radiation exit face of the thin-film semiconductor body,

wherein the projections have the shape of a right pyramid or of a right truncated pyramid with a regularly configured hexagon base,

wherein the base of the projections has a diameter between 100 nm and 10 μ

m.

2. The method according to claim 1, wherein filling the recesses and/or applying the semiconductor layer sequence comprises performing an epitaxial growth process.

3. The method according to claim 1, wherein bases of adjacent projections are in mutual contact.

4. The method according to claim 1, further comprising applying a further material onto the outcoupling structures for refractive index adaptation between the semiconductor material of the thin-film semiconductor body and a surrounding medium.

5. The method according to claim 4, wherein the refractive index of the material for refractive index adaptation is between 1 and 2.3 inclusive.

6. The method according to claim 1, wherein the outcoupling structures are formed from a nitride compound semiconductor material.

7. The method according to claim 1, further comprising applying a stop layer onto the recesses, the stop layer being provided to slow down an etching process used in the detaching step.

8. The method according to claim 7,

wherein the recesses are formed in a semiconductor layer which comprises gallium nitride;

the stop layer comprises aluminium gallium nitride; and

the semiconductor layer with the recesses is removed by a dry etching process.

9. The method according to claim 8, wherein the growth substrate comprises sapphire and is removed using a laser lift-off process.

10. The method according to claim 8, wherein the growth substrate comprises silicon and the growth substrate is removed by etching.

11. The method according to claim 1, further comprising applying a sacrificial layer between the growth substrate and the outcoupling structures, the sacrificial layer being suitable for removal using a laser lift-off process.