PROCESS FOR FORMING LIGHT-EMITTING DIODES

• US 20160155900A1
• Filed: 03/14/2014
• Published: 06/02/2016
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Original Assignee: Commissariat a L'Energie Atomique (French Alternative Energies and Atomic Energy Commission)
• Inventors: Andre, Bernard, Gasse, Adrien, Bono, Hubert
• Granted Patent: US 9,444,010 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 2933/0025 relating to coatings
• CPC Class Codes: H01L 2933/0033 relating to semiconductor body packages
• CPC Class Codes: H01L 2933/0041 relating to wavelength conversion elements
• CPC Class Codes: H01L 2933/005 relating to encapsulations
• CPC Class Codes: H01L 2933/0075 relating to heat extraction or cooling elements
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/08 with a plurality of light emitting regions, e.g. laterally discontinuous light emitting layer or photoluminescent region integrated within the semiconductor body H01L27/15 takes precedence
• CPC Class Codes: H01L 33/18 within the light emitting region
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/46 Reflective coating, e.g. dielectric Bragg reflector
• CPC Class Codes: H01L 33/502 Wavelength conversion materials
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/52 Encapsulations
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/641 characterized by the materials
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

The invention relates to a process for manufacturing light-emitting diodes comprising the following steps: a) forming light-emitting diodes (5) on a silicon layer (1) of an SOI wafer (1, 2, 3), said layer resting on a carrier (2, 3); b) bonding, on the light-emitting diode side, a silicon wafer forming a cap (7) equipped with a void facing each light-emitting diode; c) thinning the silicon wafer to form an aperture facing each light-emitting diode; d) filling each aperture with a transparent material (21, 23); and e) at least partially removing the carrier of the SOI wafer (3) and producing connecting and heat-sinking metallisations.

Claims

1. A light-emitting diode manufacturing method comprising the steps of:

a) forming light-emitting diodes on a silicon layer of an SOI-type wafer, said layer resting on a support;

b) bonding on the light-emitting diode side a silicon wafer forming a cap provided with a non-through recess opposite each light-emitting diode;

c) leveling down the bonded silicon wafer to form a through opening opposite each light-emitting diode;

d) filling each opening with a transparent material; and

e) at least partially removing the support of the SOI-type wafer from the entire SOI-type wafer and forming connection and heat sink metallizations.

2. The method of claim 1, wherein steps c), d), and e) follow one another.

3. The method of claim 1, wherein at least the removal of the support of the SOI-type wafer of step e) is carried out before steps c) and d).

4. The method of claim 1, further comprising a step of cutting into individual light-emitting diodes or into groups of light-emitting diodes.

5. The method of claim 1, wherein the lateral surfaces of each recess of the silicon wafer forming a cap are coated with a reflective deposit.

6. The method of claim 1, wherein the light-emitting diodes are nanowire light-emitting diodes.

7. The method of claim 6, wherein the nanowires are GaN nanowires.

8. The method of claim 7, wherein the nanowires are formed from a seed layer deposited on the silicon layer.

9. The method of claim 1, wherein the filling of the openings is performed with a transparent material provided with phosphors in its portion close to the light-emitting diodes.

10. The method of claim 1, wherein the external surface of the filling material is shaped to have desired optical characteristics.

11. The method of claim 1, wherein the support of the SOI-type wafer comprises a handle and an insulating layer interposed between the handle and the silicon layer and wherein, at step (e), the handle is totally removed.