LIGHT EMITTING DEVICE

• US 20120104357A1
• Filed: 01/09/2012
• Published: 05/03/2012
• Est. Priority Date: 09/12/2008
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Kondo, Katsufumi, Saeki, Ryo
• Granted Patent: US 8,384,063 B2
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate

Abstract

A light emitting device includes a stacked body including at least a light emitting layer made of In_x(Al_yGa_1-y)_1-xP(0≦x≦1, 0≦y≦1), a p-type cladding layer made of In_x(Al_yGa_1-y)_1-xP (0≦x≦1, 0≦y≦1), and a bonding layer made of a semiconductor; and a substrate in which deviation in a lattice constant at a bonding interface with the bonding layer is larger than deviation in lattice constants between the light emitting layer and the bonding layer. The p-type cladding layer is located more distant from the bonding interface than the light emitting layer, and the p-type cladding layer has a carrier concentration of 0.5×10¹⁷ cm⁻³ or more and 3×10¹⁷ cm⁻³ or less.

Claims

1. A light emitting device comprising:

a stacked body including at least a light emitting layer made of In_x(Al_yGa_1-y)_1-xP (0≦

x≦

1, 0≦

y≦

1), a p-type cladding layer made of In_x(Al_yGa_1-y)_1-xP (0≦

x≦

1, 0≦

y≦

1), and a bonding layer made of a semiconductor; and

a substrate in which deviation in a lattice constant at a bonding interface with the bonding layer is larger than deviation in lattice constants between the light emitting layer and the bonding layer,

the p-type cladding layer being located more distant from the bonding interface than the light emitting layer, and

the p-type cladding layer having a carrier concentration of 0.5×

10¹⁷ cm<sup>−

3</sup> or more and 3×

10¹⁷ cm<sup>−

3</sup> or less.

2. The light emitting device according to claim 1, further comprising:

a p-side electrode,

the stacked body being made of p-type In_x(Al_yGa_1-y)_1-xP (0≦

x≦

1, 0≦

y≦

1) or GaP and further including a current diffusion layer provided between the p-side electrode and the p-type cladding layer.

3. The light emitting device according to claim 2, further comprising:

a contact layer provided between the p-side electrode and the current diffusion layer, having generally the same size as the p-side electrode, and made of p-type GaAs.

4. The light emitting device according to claim 1, wherein the light emitting layer has a multi-quantum well structure.

5. The light emitting device according to claim 1, wherein the light emitting layer is of p-type and the carrier concentration in the light emitting layer is less than or equal to the carrier concentration in the p-type cladding layer.

6. The light emitting device according to claim 5, wherein the p-type cladding layer and the light emitting layer are doped with an acceptor, which is one of Zn, Mg, and C.

10. The light emitting device according to claim 1, wherein

the substrate is transparent to emission light from the light emitting layer and has high resistance, and

an n-side electrode is formed on part of a surface of the bonding layer on the opposite side of the bonding interface.

11. The light emitting device according to claim 10, wherein the substrate is made of one of sapphire and GaP.

7. A light emitting device comprising:

a stacked body including at least a light emitting layer made of In_x(Al_yGa_1-y)_1-xP (0≦

x≦

1, 0≦

y≦

1), a p-type cladding layer made of In_x(Al_yGa_1-y)_1-xP (0≦

x≦

1, 0≦

y≦

1), and a bonding layer made of a semiconductor; and

a substrate in which deviation in a lattice constant at a bonding interface with the bonding layer is larger than deviation in lattice constants between the light emitting layer and the bonding layer, the substrate being conductive and transparent to emission light from the light emitting layer,

the p-type cladding layer being located more distant from the bonding interface than the light emitting layer,

the p-type cladding layer having a carrier concentration of 0.5×

10¹⁷ cm<sup>−

3</sup> or more and 3×

10¹⁷ cm<sup>−

3</sup> or less, and

the light emitting layer and the p-type cladding layer being sequentially crystal grown on a surface of the bonding layer on the opposite side of the bonding interface.

8. The light emitting device according to claim 7, wherein the substrate is made of n-type GaP.

9. The light emitting device according to claim 8, wherein the bonding layer is made of In_x(Al_yGa_1-y)_1-xP (0≦

x≦

1, 0≦

y≦

1).