Light-emitting semiconductor device using group III nitride compound

• US 5,959,401 A
• Filed: 05/21/1997
• Issued: 09/28/1999
• Est. Priority Date: 05/21/1996
• Status: Expired due to Term

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Koike, Masayoshi, Asami, Shinya
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Smith, Michael J.
• Application Number:
  US08/861,116
• Time in Patent Office: 860 Days
• Field of Search: 313/503, 313/501, 313/499, 313/504
• US Class Current: 313/503
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01L 33/325 characterised by the doping materials

Abstract

A light-emitting semiconductor device consecutively includes a sapphire substrate, an AlN buffer layer, a silicon (Si) doped n⁺ -layer GaN, a Si-doped n-type GaN, a zinc (Zn) and Si-doped In₀.20 Ga₀.80 N emission layer, a magnesium (Mg) doped p-type Al₀.08 Ga₀.92 N layer as a cladding layer, an Mg-doped p-type GaN layer as a first contact layer, and an Mg-doped p⁺ -type GaN layer as a second contact layer. The cladding layer and the first and second contact layers have a total thickness of 10 nm to 150 nm which is thinner than that of a conventional p-layers by a half to one thirtieth. The emission layer is exposed to high growth temperature for 1.3 min. to 20 min. which is shorter than that of the conventional emission layer by a half to one thirtieth. As a result, crystallinity of the emission layer is improved, because it is prevented that In of the emission layer diffuses into the cladding and the contact layers, that N of the emission layer evaporates, and that Mg of the cladding and the contact layers diffuses into the emission layer.

Claims

1. A light-emitting device using group III nitride compound semiconductor, comprising:

an emission layer of group III nitride compound semiconductor satisfying the formula Al_x1 Ga_y1 In_1-x1-y1 N, inclusive of 0≦

x1≦

1, 0≦

y1≦

1 and 0≦

x1+y1≦

1;

a cladding layer formed on said emission layer and made of group III nitride compound semiconductor satisfying the formula Al_x2 Ga_y2 In_1-x2-y2 N, inclusive of 0≦

x2≦

1, 0≦

y2≦

1 and 0≦

x2+y2≦

1;

a contact layer formed on said cladding layer and made of group III nitride compound semiconductor satisfying the formula Al_x3 Ga_y3 In_1-x3-y3 N, inclusive of 0≦

x3≦

1, 0≦

y3≦

1 and 0≦

x3+y3≦

1; and

wherein total thickness of said cladding layer and said contact layer is in the range of 10 nm to 150 nm.

2. A light-emitting device of claim 1, wherein said cladding layer is doped with an acceptor impurity and exhibits p-type conduction.

3. A light-emitting device of claim 1, wherein said contact layer is doped with an acceptor impurity and exhibits p-type conduction.

4. A light-emitting device of claim 1, wherein said cladding layer is made of a three element compound satisfying the formula Al_y4 Ga_1-y4 N where 0≦

y4≦

1.

5. A light-emitting device of claim 1, wherein said contact layer is made of gallium nitride (GaN).

6. A light-emitting device of claim 2, wherein said acceptor impurity is magnesium (Mg).

7. A light-emitting device of claim 3, wherein said acceptor impurity is magnesium (Mg).

8. A light-emitting-device of claim 1, wherein said emission layer is doped with an acceptor impurity and a donor impurity.

9. A light-emitting device of claim 8, wherein said acceptor impurity is zinc (Zn) and said donor impurity is silicon (Si).

10. A light-emitting device of claim 1, wherein said emission layer has one of a single quantum well structure and a multi-quantum well structure.

11. A light-emitting device or claim 1, wherein said emission layer is a non-doped layer.

12. A light-emitting device of claim 10, wherein said emission layer is a non-doped layer.

13. A light-emitting device of claim 7, wherein said contact layer has a double layer structure including a first contact layer doped with magnesium (Mg) in the range of 1×

10¹⁹ /cm³ to 5×

10²⁰ /cm³ and a second contact layer doped with magnesium (Mg) in the range of 1×

10²⁰ /cm³ to 1×

10²¹ /cm³.