Light emitting device

• US 8,115,192 B2
• Filed: 05/01/2009
• Issued: 02/14/2012
• 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
• Primary Examiner(s): DANG, PHUC T
• Application Number:
  US12/434,056
• Publication Number:
  US 20100065813A1
• Time in Patent Office: 1,019 Days
• Field of Search: 257/13, 257/14, 257/88, 372/43, 372/45, 372/64
• 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 substrate;

a p-side electrode;

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

x≦

1, 0≦

y≦

1) or GaP, and a contact layer, the current diffusion layer being provided between the p-side electrode and the p-type cladding layer;

a first metal layer provided on the contact layer and being capable of reflecting emission light from the light emitting layer; and

a second metal layer provided on the substrate and bonded to the first metal layer,

the p-type cladding layer being located more distant from a bonding interface between the first metal layer and the second metal layer than the light emitting layer, and the p-type cladding layer having a carrier concentration of 0.5×

10¹⁷ cm³ or more and 3×

10¹⁷ cm³ or less.

2. The light emitting device according to claim 1, 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.

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

4. 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.

5. The light emitting device according to claim 4, wherein the p-type cladding layer and the light emitting layer are doped with an acceptor, which is one of Zn, Mg, and C.

6. The light emitting device according to claim 1, wherein the substrate is made of n-type Si.

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

an n-side electrode formed on a surface of the substrate on the opposite side of the bonding interface.

8. The light emitting device according to claim 1, wherein the first metal layer is a stacked layer of AuGe and Au, or is made of AuGe, the second metal layer is made of Au, and the bonding interface is bonded with AuGe eutectic solder.