Light emitting nitride semiconductor device, and light emitting apparatus and pickup device using the same

• US 6,399,966 B1
• Filed: 09/07/2001
• Issued: 06/04/2002
• Est. Priority Date: 09/08/2000
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tsuda, Yuhzoh, Ito, Shigetoshi
• Primary Examiner(s): Niebling, John F.
• Application Number:
  US09/947,346
• Publication Number:
  US 20020053665A1
• Time in Patent Office: 270 Days
• Field of Search: 257/101, 257/103, 257/98, 257/79, 257/102
• US Class Current: 257/103
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G11B 7/127 Lasers; Multiple laser arrays lasers per se H01S
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/325 characterised by the doping materials
• CPC Class Codes: H01S 5/04253 having specific optical properties, e.g. transparent electrodes
• CPC Class Codes: H01S 5/22 having a ridge or stripe structure
• CPC Class Codes: H01S 5/34333 with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser

Abstract

There is provided a light emitting device having high luminous efficacy or emission intensity. The device includes a light emitting layer provided between n- and p-type layers of nitride semiconductor formed on a GaN substrate. The light emitting layer is formed of a well layer or a combination of well and barrier layers. The well layer is made of a nitride semiconductor containing an element X, N and Ga, wherein X is As, P or Sb. The ratio of the number of the atoms of element X to the sum of the number of the atoms of element X and N, is not more than 30 atomic percent. The well layer contains Mg, Be, Zn, Cd, C, Si, Ge, Sn, O, S, Se or Te as an impurity for improving the crystallinity of the well layer.

Claims

1. A light emitting nitride semiconductor device, comprising:

a substrate made of nitride semiconductor crystal or a substrate having a nitride semiconductor crystal film grown on a crystalline material other than said nitride semiconductor crystal;

an n-type layer and a p-type layer made of nitride semiconductor and formed on said substrate; and

a light emitting layer provided between said n- and p-type layers, wherein

said light emitting layer is formed of a well layer or a combination of well and barrier layers;

of said layer or layers forming said light emitting layer, at least said well layer is made of a nitride semiconductor containing elements X, N and Ga, said element X being at least one selected from the group consisting of As, P and Sb;

in said nitride semiconductor forming said light emitting layer, the ratio of the number of the atoms of said element X to the sum of said number of the atoms of said element X and the number of the atoms of said N, is not more than 30 atomic percent; and

of said layer or layers forming said light emitting layer, at least said well layer contains as an impurity at least one element selected from the group consisting of Mg, Be, Zn, Cd, C, Si, Ge, Sn, O, S, Se and Te.

2. The light emitting nitride semiconductor device of claim 1, wherein said impurity is contained so as to improve crystallinity of said well layer.

3. The light emitting nitride semiconductor device of claim 1, wherein a total content of said impurity is 1×

10¹⁷ to 5×

10²⁰/cm³.

4. The light emitting nitride semiconductor device of claim 1, wherein said nitride semiconductor crystal or said nitride semiconductor crystal film of said substrate or said light emitting nitride semiconductor device has a threading dislocation density of not more than 3×

10⁷/cm² or an etch pit density of not more than 7×

10⁷/cm².

5. The light emitting nitride semiconductor device of claim 3, wherein said nitride semiconductor crystal or said nitride semiconductor crystal film of said substrate or said light emitting nitride semiconductor device has a threading dislocation density of not more than 3×

10⁷/cm² or an etch pit density of not more than 7×

10⁷/cm².

6. The light emitting nitride semiconductor device of claim 1, wherein said light emitting layer is a multi-quantum well layer.

7. The light emitting nitride semiconductor device of claim 3, wherein said light emitting layer is a multi-quantum well layer.

8. The light emitting nitride semiconductor device of claim 4, wherein said light emitting layer is a multi-quantum well layer.

9. A light emitting apparatus, comprising said light emitting nitride semiconductor device as recited in claim 1 and having an emission wavelength of 360 nm to 650 nm.

10. An optical pickup apparatus, comprising a light emission apparatus comprising said light emitting nitride semiconductor device as recited in claim 1 and having an oscillation wavelength of 360 nm to 420 nm.