SEMICONDUCTOR LIGHT EMITTING DEVICE

• US 20080283822A1
• Filed: 05/16/2008
• Published: 11/20/2008
• Est. Priority Date: 05/17/2007
• Status: Abandoned Application

• Current Assignee: Eudyna Devices Inc. (Sumitomo Corporation)
• Original Assignee: Eudyna Devices Inc. (Sumitomo Corporation)
• Inventors: YUI, Keiichi
• Application Number:
  US12/122,298
• Publication Number:
  US 20080283822A1
• Time in Patent Office: Days
• US Class Current: 257/13
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/32 containing nitrogen

Abstract

A semiconductor light emitting device includes a substrate and a quantum well active layer. The quantum well active layer has a plurality of barrier layers made of GaN-based semiconductor and a well layer made of GaN-based semiconductor sandwiched between the barrier layers and has polarized charge between the barrier layer and the well layer caused by piezo polarization. The well layer has a composition modulation so that a band gap is minimum at an interface between the well layer and one of the barrier layers more far from the substrate than the other.

Claims

1. A semiconductor light emitting device comprising:

a substrate; and

a quantum well active layer that has a plurality of barrier layers made of GaN-based semiconductor and a well layer made of GaN-based semiconductor sandwiched between the barrier layers and has polarized charge between the barrier layer and the well layer caused by piezo polarization,

the well layer having a composition modulation so that a band gap is minimum at an interface between the well layer and one of the barrier layers more far from the substrate than the other.

2. The semiconductor light emitting device as claimed in claim 1, wherein a main face of the barrier layer and the well layer is (0001) face or (11-22) face.

3. The semiconductor light emitting device as claimed in claim 1, wherein the composition modulation of the well layer is that of In.

4. The semiconductor light emitting device as claimed in claim 1, wherein the composition modulation is gradual modulation or stepwise modulation.

5. The semiconductor light emitting device as claimed in claim 1, wherein the barrier layer is made of Al_aIn_bGa_1-a-bN (0≦

a≦

1, 0≦

b≦

1) and the well layer is made of Al_cIn_dGa_1-c-dN (0≦

c≦

1, 0≦

d≦

1).

6. The semiconductor light emitting device as claimed in claim 1, wherein the substrate is made of SiC, Si, sapphire, GaN or Ga₂O₃.