Semiconductor device, surface emitting semiconductor laser and edge emitting semiconductor laser

• US 6,597,017 B1
• Filed: 03/07/2000
• Issued: 07/22/2003
• Est. Priority Date: 03/26/1999
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Xerox Company Limited (Fujifilm Holdings Corporation)
• Inventors: Sakamoto, Akira, Seko, Yasuji
• Primary Examiner(s): Pham, Long
• Assistant Examiner(s): LOUIE, WAI SING
• Application Number:
  US09/520,188
• Time in Patent Office: 1,232 Days
• Field of Search: 438/30, 438/36, 438/37, 438/46, 438/47, 438/438
• US Class Current: 257/79
• CPC Class Codes: H01S 2304/04 MOCVD or MOVPE
• CPC Class Codes: H01S 5/18308 having a special structure for lateral current or light confinement
• CPC Class Codes: H01S 5/18361 Structure of the reflectors, e.g. hybrid mirrors
• CPC Class Codes: H01S 5/2063 obtained by particle bombardment
• CPC Class Codes: H01S 5/3201 incorporating bulkstrain effects, e.g. strain compensation, strain related to polarisation
• CPC Class Codes: H01S 5/32341 blue laser based on GaN or GaP

Abstract

Provided is a semiconductor device that has pseudo lattice matched layers with good crystallinity, formed with lattice mismatched materials. Tensile-strained n-type Al_0.5Ga_0.5N layers (lower side) and compressive-strained n-type Ga_0.9In_0.1N layers (upper side) are grown on a GaN crystal layer substrate in 16.5 periods to form an n-type DBR mirror; an undoped GaN spacer layer and an active region are grown on the n-type DBR mirror; and an undoped a GaN spacer layer is grown on the active region. Further, tensile-strained p-type Al_0.5Ga_0.5N layers (lower side) and compressive-strained p-type Ga_0.9In_0.1N layers (upper side) are grown on the spacer layer in 12 periods to form a p-type DBR mirror and eventually complete a surface emitting semiconductor laser.

Claims

1. A surface emitting semiconductor laser comprising:

a semiconductor base layer made of a semiconductor crystal whose in-plane lattice constant is a₀;

a cladding layer or DBR mirror including a first layer made of a semiconductor crystal having an in-plane lattice constant a₁, and a second layer made of a semiconductor crystal having an in-plane lattice constant a₂, wherein

4. The surface emitting semiconductor laser according to claim 1, wherein an in-plane lattice constant a_x of the pseudo lattice matched layer satisfies a relation described below in connection with the in-plane lattice constant a₀ of the semiconductor crystal of the semiconductor base layer:

5. The surface emitting semiconductor laser according to claim 1, wherein an in-plane lattice constant a₁ of the semiconductor crystal of the first layer and an in-plane lattice constant a₂ of the semiconductor crystal of the second layer satisfy the relation described below:

6. The surface emitting semiconductor laser according to claim 1, wherein the pseudo lattice matched layer is formed by alternately stacking the first and second layers.

7. The surface emitting semiconductor laser according to claim 1, wherein the pseudo lattice matched layer includes a third layer made of a semiconductor crystal whose in-plane lattice constant is a₀ in addition to the first and second layers.

8. The surface emitting semiconductor laser according to claim 1, wherein at least one of the first and second layers is formed by stacking plural semiconductor crystals with different in-plane lattice constants.

9. The surface emitting semiconductor laser according to claim 1, wherein each layer of the pseudo lattice matched layer has a thickness equal to or less than 10 nm.

10. The surface emitting semiconductor laser according to claim 1, wherein a bandgap of the pseudo lattice matched layer is larger than a bandgap of the semiconductor crystal of the semiconductor base layer.

11. The surface emitting semiconductor laser according to claim 1, wherein the pseudo lattice matched layer is formed by alternately stacking high and low refractive index regions.

12. The semiconductor device according to claim 11, wherein the high refractive index region and the low refractive index region are alternatively stacked with each region of mλ

/4 in thickness, where λ

is an emission wavelength from an active region and m=1 or 3, to form a distributed-Bragg reflector mirror.

13. A surface emitting semiconductor laser comprising:

the semiconductor device according to claim 1, wherein the psuedo lattice matching layer is a first distributed-Bragg reflector mirror, and the functioning layer is formed on the first distributed-Bragg reflector mirror, which performs recombination of carriers; and

a second distributed-Bragg reflector mirror that sandwiches the functioning layer with the first distributed-Bragg reflector mirror, to form a resonator mirror structure with the first and second distributed-Bragg reflector mirrors.

14. The surface emitting semiconductor laser according to claim 1, wherein the second distributed-Bragg reflector mirror is a distributed-Bragg reflector mirror of a pseudo lattice matching type including a first layer made of a semiconductor crystal whose in-plane lattice constant is larger than a₀ and a second layer made of a semiconductor crystal whose in-plane lattice constant is smaller than a₀, the second distributed-Bragg reflector mirror of a pseudo lattice matching type being formed while being subjected to pseudo lattice matching by epitaxially growing the first and second layers on the semiconductor base layer such that lattice strains produced in the first and second layers assume opposite directions.

15. An edge emitting semiconductor laser comprising:

the semiconductor device according to claim 1, wherein the psuedo lattice matching layer comprises a first cladding layer, the functioning layer is formed on the first cladding layer, which performs recombination of carriers, and the functioning layer and the first cladding layer are arranged at different vertical levels vertically above the semiconductor base layer;

further comprising a second cladding layer that sandwiches the functioning layer with the first cladding layer, to achieve light confinement in the functioning layer; and

a pair of edge reflector mirrors disposed in an opposite manner, which resonate light generated in the functioning layer in a predetermined plane direction of the functioning layer.

2. A surface emitting semiconductor laser comprising:

a semiconductor base layer made of a semiconductor crystal whose in-plane lattice constant is a₀;

a cladding layer or DBR mirror including a first layer made of a semiconductor crystal having an in-plane lattice constant a₁, and a second layer made of a semiconductor crystal having an in-plane lattice constant a₂, wherein

3. A surface emitting semiconductor laser comprising:

a semiconductor base layer made of a semiconductor crystal whose in-plane lattice constant is a₀;

a cladding layer or DBR mirror including a first layer made of a semiconductor crystal having an in-plane lattice constant a₁, and a second layer made of a semiconductor crystal having an in-plane lattice constant a₂, wherein