Nitride-based compound semiconductor light emitting device and fabricating method thereof

• US 20060006398A1
• Filed: 07/08/2005
• Published: 01/12/2006
• Est. Priority Date: 07/08/2004
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Hata, Toshio
• Granted Patent: US 7,439,551 B2
• Time in Patent Office: Days
• US Class Current: 257/94
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48463 the connecting portion on the bonding area of the semiconductor or solid-state body being a ball bond
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/12041 LED
• CPC Class Codes: H01L 33/0093 Wafer bonding; Removal of the growth substrate
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

The nitride-based compound semiconductor light emitting device includes a first ohmic electrode, a bonding metal layer, a second ohmic electrode, a nitride-based compound semiconductor layer, and a transparent electrode stacked in this order on a support substrate, and further includes an ohmic electrode formed on a back side of the support substrate.

Claims

1. A nitride-based compound semiconductor light emitting device, comprising:

a support substrate;

a first ohmic electrode formed on the support substrate;

a bonding metal layer formed on the first ohmic electrode;

a second ohmic electrode formed on the bonding metal layer;

a nitride-based compound semiconductor layer formed on the second ohmic electrode;

a transparent electrode formed on an approximately entire upper surface of the semiconductor layer; and

an ohmic electrode formed on a back side of said support substrate.

2. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said nitride-based compound semiconductor layer has at least a P-type layer, a light emitting layer and an N-type layer stacked in this order from the side of the support substrate.

3. The nitride-based compound semiconductor light emitting device according to claim 2, wherein a reflecting layer for reflecting light from said light emitting layer is formed between said second ohmic electrode and said bonding metal layer.

4. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said support substrate is conductive and formed of at least one of Si, GaAs and GaP, and has resistivity in a range from 10⁻

4 Ω

cm to 10 Ω

cm.

5. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said support substrate is conductive and formed of at least one of CuW, CuAg and CuMo, and has thermal conductivity in a range from 1.5 W/cm·

k to 2.5 W/cm·

k.

6. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said bonding metal layer consists of at least two layers formed of same or different materials with respect to each other.

7. The nitride-based compound semiconductor light emitting device according to claim 6, wherein the at least two layers of said bonding metal layer are formed of at least two different metals selected from Au, Sn, AuSn and Au—

Ge.

8. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said bonding metal layer is formed of a metal selected from Au, Sn, AuSn and Au—

Ge.

9. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said second ohmic electrode has a thickness in a range from 1 nm to 15 nm.

10. The nitride-based compound semiconductor light emitting device according to claim 1, wherein said nitride-based compound semiconductor layer is formed on an insulative substrate of sapphire, spinel or lithium niobate, or on a conductive substrate of silicon carbide, silicon, zinc oxide or gallium arsenide.

11. The nitride-based compound semiconductor light emitting device according to claim 10, wherein said insulative substrate or said conductive substrate is removed by grinding, polishing or laser lift-off.

12. A fabricating method of a nitride-based compound semiconductor light emitting device, comprising the steps of:

forming a nitride-based compound semiconductor layer on a substrate;

forming a second ohmic electrode on the nitride-based compound semiconductor layer;

forming a second bonding metal layer on the second ohmic electrode;

forming a first ohmic electrode on a support substrate;

forming a first bonding metal layer on the first ohmic electrode;

bonding said first bonding metal layer and said second bonding metal layer;

removing said substrate to expose a surface of said nitride-based compound semiconductor layer; and

forming a transparent electrode on the exposed surface.

13. The fabricating method of a nitride-based compound semiconductor light emitting device according to claim 12, wherein said step of forming the nitride-based compound semiconductor layer on the substrate includes the step of stacking at least an N-type layer, a light emitting layer and a P-type layer in this order from the substrate side.

14. The fabricating method of a nitride-based compound semiconductor light emitting device according to claim 12, further comprising the step of forming a reflecting layer on said second ohmic electrode between said step of forming the second ohmic electrode and said step of forming the second bonding metal layer, wherein

said step of forming the second bonding metal layer includes the step of forming the second bonding metal layer on the reflecting layer.

15. The fabricating method of a nitride-based compound semiconductor light emitting device according to claim 12, further comprising the steps of:

removing a part of said nitride-based compound semiconductor layer to expose said second ohmic electrode;

irradiating the exposed metal surface with laser light;

forming a scribe line from the side of the support substrate opposite to the portion irradiated with the laser light; and

performing dividing along the scribe line.