Gallium nitride type compound semiconductor light emitting element

• US 5,793,054 A
• Filed: 06/13/1996
• Issued: 08/11/1998
• Est. Priority Date: 06/15/1995
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: NEC Corporation
• Inventors: Nido, Masaaki
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): KELLEY, NATHAN K
• Application Number:
  US08/662,697
• Time in Patent Office: 789 Days
• Field of Search: 257/14, 257/18, 257/22, 257/94, 257/103, 257/627, 257/628
• US Class Current: 257/18
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• 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
• CPC Class Codes: H01S 5/0213 Sapphire, quartz or diamond based substrates
• CPC Class Codes: H01S 5/3086 doping of the active layer
• CPC Class Codes: H01S 5/3201 incorporating bulkstrain effects, e.g. strain compensation, strain related to polarisation
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

A gallium nitride type compound semiconductor light emitting element, such as a semiconductor laser, a light emitting diode is constructed by forming an In₀.06 Ga₀.94 N buffer layer, an n-type In₀.06 Ga₀.94 N clad layer, an n-type In₀.06 Al₀.15 Ga₀.79 N clad layer, an undoped GaN active layer having layer thickness of 50 nm, a p-type In₀.06 Al₀.15 Ga₀.79 N clad layer and a p-type In₀.06 Ga₀.94 N cap layer on a (0001) azimuth sapphire substrate. A p-side electrode is formed on the p-type In₀.06 Ga₀.94 N cap layer, and an n-side electrode is formed on the n-type In₀.06 Ga₀.94 N clad layer. In the construction set forth above, a greater thickness for the active layer is provided. Also, tensile strain is applied to the active layer. Light is taken out in parallel direction to the substrate. This threshold current of the semiconductor laser is lowered and light emitting efficiency of the light emitting diode is improved.

Claims

1. A gallium nitride type compound semiconductor light emitting element comprising a quantum well layer consisting of a Ga_x Al_1-x N layer (0≦

x≦

1) having a Wurtzite structure on a <

0001>

azimuth substrate surface, as a light emitting layer, said quantum well layer having a layer thickness greater than or equal to 10 nm and being under tensile strain, and light is taken out in parallel direction to said substrate surface.

2. A gallium nitride type compound semiconductor light emitting element as set forth in claim 1, wherein light is deflected from said light emitting element in a direction perpendicular to the substrate surface.

3. A gallium nitride type compound semiconductor light emitting element as set forth in claim 1, wherein said quantum well layer is under tensile strain of less than or equal to 3%.

4. A gallium nitride type compound semiconductor light emitting element as set forth in claim 1, and comprising a clad layer and a multi quantum well barrier layer both formed of InAlGaN.

5. A gallium nitride type compound semiconductor light emitting element as set forth in claim 4, wherein said multi quantum well barrier layer is doped by a p-type impurity.

6. A gallium nitride type compound semiconductor light emitting element as set forth in claim 4, wherein an InGaN buffer layer and an InGaN clad layer are formed on a sapphire substrate having a (0001) surface as major surface or on a GaAs substrate having a (001) surface as major surface, and said clad layer and active layer are formed thereon.