III-V Semiconductor heterostructure contacting a P-type II-VI compound

• US 5,442,204 A
• Filed: 05/12/1994
• Issued: 08/15/1995
• Est. Priority Date: 05/12/1994
• Status: Expired due to Fees

• Current Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Original Assignee: Philips Electronics North America Corporation (Koninklijke Philips N.V.)
• Inventors: Mensz, Piotr M.
• Primary Examiner(s): Saadat, Mahshid D.
• Application Number:
  US08/241,840
• Time in Patent Office: 460 Days
• Field of Search: 257/97, 257/103, 257/185, 257/191, 257/200, 257/201
• US Class Current: 257/103
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: H01L 29/221 including two or more compounds , e.g. alloys H01L29/2206 takes precedence
• CPC Class Codes: H01L 29/267 in different semiconductor regions , e.g. heterojunctions H01L29/263 takes precedence
• CPC Class Codes: H01L 33/0087 with a substrate not being a II-VI compound
• CPC Class Codes: H01L 33/28 containing only elements of Group II and Group VI of the Periodic Table
• CPC Class Codes: H01S 5/0421 characterised by the semiconducting contacting layers electrodes H01S5/0425
• CPC Class Codes: H01S 5/327 in AIIBVI compounds, e.g. ZnCdSe-laser
• CPC Class Codes: H01S 5/347 in AIIBVI compounds, e.g. ZnCdSe- laser

Abstract

A semiconductor structure useful in blue light emitting diodes and diode lasers is disclosed. The structure is formed of a substrate of p- type GaAs, a layer of a p- type II-VI compound of the formula Zn_x Q_1-x S_y Se_1-x where Q=Mg, Cd or Mn, 0.5≦x≦1 and 0≦y≦1, separated from the substrate by a series of thin epitaxial undoped or p-doped layers including a layer of In₀.5 Al₀.5 P in contact with the layer of the II-VI compound, a layer of In₀.5 Ga₀.5 P or of Al_x Ga_1-x As where x=0.1-0.3 contacting the substrate, a layer of In₀.5 Ga₀.5 P contacting the layer of Al_x Ga_1-x P and at least one layer of In₀.5 Al₂ Ga₀.5-z P where 0<z<0.5 and the value of z decreases in the direction of the layer of In₀.5 Ga₀.5 P provided between and contacting the layer of In₀.5 Al₀.5 P and the layer of In₀.5 Ga₀.5 P.

Claims

1. A semiconductor structure comprising a first layer of a p-type II-VI compound of the formula Zn_x Q_1-x S_y Se_1-y wherein Q is an element selected from the group consisting of Mg, Cd and Mn, 0.5≦

x≦

1 and 0≦

y≦

1 and a substrate of p-type GaAs, said first layer and said substrate being separated by a series of thin epitaxial undoped or p-doped layers of a total thickness of up to 2 μ

m and each layer of a thickness of 20 Å

to 2000 Å

contacting opposing surfaces of said substrate and said first layer, said series of layers comprising a layer of In₀.5 Al₀.5 P contacting the opposing surface of said first layer, a layer of a compound selected from the group consisting of In₀.5 Ga₀.5 P and Al_x Ga_1-x As wherein x=0.1-0.3 contacting the opposing surface of said substrate, a layer of In₀.5 Ga₀.5 P contacting said layer of Al_x Ga_1-x As, at least one layer of In₀.5 Al₂ Ga₀.5-z P wherein 0<

z<

0.5, the value of z decreasing in the direction of said layer of In₀.5 Ga₀.5 P provided between, and having surfaces contacting said layer of In₀.5 Al₀.5 P and said layer of In₀.5 Ga₀.5 P.

2. The semiconductor structure of claim 1 wherein the at least on layer of In₀.5 Al₂ Ga₀.5-z P is undoped and the thickness of each layer in said series of layers is 20 Å

to 500 Å

.

3. A semiconductor structure comprising

a first layer of a p-type II-VI compound of the formula Zn_x Q_i-x S_y Se_1-y wherein Q is an element selected from the group consisting of Mg, Cd and Mn, 0.5<

x<

1 and x/y=1/2, in ohmic contact with a substrate of p-type GaAs, said first layer and said substrate being separated by a series of thin epitaxial layers, each of a thickness of 200Å

to 2000Å and

of a total thickness of up to 2 μ

m, a layer of p-type compounds contacting opposing surfaces of said first layer at said substrate, a layer of p-type In₀.5 Al₀.5 P contacting the opposing surface of said first layer, a layer selected from the group consisting of p-type In₀.5 Ga₀.5 P and of p-type Al_x Ga_1-x As₂ wherein x=0.1-0.3 contacting the opposing surface of said substrate, a layer of p-type In₀.5 Ga₀.5 P contacting said layer of p-type Al_x Ga_1-x As, at least one layer of p-type In₀.5 Al_z Ga₀.5-Z P wherein 0<

z<

0.5 provided between, and contacting said layer of p-type In₀.5 Ga₀.5 P and said layer of n-type In₀.5 Al₀.5 P, the value of z decreasing in the direction of said layer of p-type In₀.5 Ga₆.5 P.

4. The semiconductor structure of claim 3 wherein said at least one layer of p-type In₀₁₅ Al₂ Ga₀.5-z P is a single layer with the value of z decreasing in the direction of said layer of p-type In₀.5 Ga₀.5 P.

5. The semiconductor structure of claim 4 wherein the p-type II-VI compound is a p-type ZnSSe.

6. The semiconductor structure of claim 3 wherein said at least one layer of p-type In₀.5 Al_z Ga₀.5-z P comprises at least two sublayers of p-type In₀.5 Al_z Ga₀.5-z P in which in said at least two layers the value of z decreases in the direction of said layer of p-type In₀.5 Ga₀.5 P.

7. The semiconductor structure of claim 6 wherein the p-type II-VI compound is p-type ZnSSe.

8. The semiconductor structure of claim 3 wherein the p-type II-VI compound is a p-type ZnSSe.

9. The semiconductor structure of claim 8 wherein each of said layers other than the layer of p-type ZnSSe and said substrate is p-doped with Zn to a dopant concentration of at least 10¹⁶ cm^-3.

10. The semiconductor structure of claim 9 wherein each of said layers other than the layer of p-type ZnSSe and said substrate is p-doped with Zn to a dopant concentration of 10¹⁶ cm^-3 _-- 10¹⁸ cm^-3.

11. The semiconductor structure of claim 10 wherein the layer of p-type ZnSSe is doped with N.

12. The semiconductor structure of claim 3 wherein each of said layers other than the layer of the p-type II-VI compound has a thickness of 250Å

-1000Å

.

13. The semiconductor structure of claim 3 wherein each of said layers other than the layer of the II-VI compound Zn and said substrate is p-doped with Zn to a dopant concentration of at least 10¹⁶ cm^-3.

14. The semiconductor structure of claim 13 wherein the layer of the p-type II-VI compound is doped with N.

15. A semiconductor diode capable of emitting radiation in the blue-green light emitting region when electrically activated comprising the semiconductor structure of claim 3, a layer selected from the group consisting of n-type ZnSe and ZnSSe provided on a surface of said first layer of p-type II-VI compound and electrically conductive contacts provided on said surface and said first layer.

16. A diode laser capable of emitting radiation in the blue-green light emitting region comprising a lasing region, guiding layers contacting opposing surfaces of the lasing region, cladding layers contacting surfaces of said guiding layers remote from said lasing region and electric contacts provided on surfaces of said cladding layers remote from said guiding layer, one of said cladding layers being formed of the semiconductor structure of claim 3 with a surface of said first layer of a p-type II-VI compound contracting a surface of a guiding layer.