Method of strain engineering and related optical device using a gallium and nitrogen containing active region

• US 10,283,938 B1
• Filed: 02/03/2017
• Issued: 05/07/2019
• Est. Priority Date: 11/05/2010
• Status: Active Grant

• Current Assignee: Kyocera SLD Laser Incorporated (Kyocera Corporation)
• Original Assignee: Soraa Laser Diode, Inc. (Kyocera Corporation)
• Inventors: Raring, James W., Elsass, Christiane Poblenz
• Primary Examiner(s): Menz, Laura M
• Application Number:
  US15/424,516
• Time in Patent Office: 823 Days
• CPC Class Codes: H01L 21/02389 Nitrides
• CPC Class Codes: H01L 21/02433 Crystal orientation
• CPC Class Codes: H01L 21/02458 Nitrides
• CPC Class Codes: H01L 21/02507 Alternating layers, e.g. superlattice
• CPC Class Codes: H01L 21/0254 Nitrides
• CPC Class Codes: H01L 21/0262 Reduction or decomposition of gaseous compounds, e.g. CVD
• CPC Class Codes: H01L 33/0075 comprising nitride compounds
• CPC Class Codes: H01L 33/06 within the light emitting region, e.g. quantum confinement structure or tunnel barrier
• CPC Class Codes: H01L 33/12 with a stress relaxation structure, e.g. buffer layer
• CPC Class Codes: H01L 33/16 with a particular crystal structure or orientation, e.g. polycrystalline, amorphous or porous
• CPC Class Codes: H01L 33/32 containing nitrogen
• CPC Class Codes: H01S 5/1082 with a special facet structure, e.g. structured, non planar, oblique
• CPC Class Codes: H01S 5/2009 by using electron barrier layers
• CPC Class Codes: H01S 5/2018 Optical confinement, e.g. absorbing-, reflecting- or waveguide-layers
• CPC Class Codes: H01S 5/2031 characterized by special waveguide layers, e.g. asymmetric waveguide layers or defined bandgap discontinuities
• CPC Class Codes: H01S 5/2201 in a specific crystallographic orientation
• CPC Class Codes: H01S 5/3063 using Mg
• CPC Class Codes: H01S 5/3201 incorporating bulkstrain effects, e.g. strain compensation, strain related to polarisation
• CPC Class Codes: H01S 5/3202 grown on specifically orientated substrates, or using orientation dependent growth
• CPC Class Codes: H01S 5/320275 semi-polar orientation
• CPC Class Codes: H01S 5/3213 : asymmetric clading layers
• CPC Class Codes: H01S 5/3403 : having a strained layer structure in which the strain performs a special function, e.g. general strain effects, strain versus polarisation
• CPC Class Codes: H01S 5/3406 : including strain compensation
• CPC Class Codes: H01S 5/34333 : with a well layer based on Ga(In)N or Ga(In)P, e.g. blue laser
• CPC Class Codes: H01S 5/34346 : characterised by the materials of the barrier layers

Abstract

An optical device has a gallium and nitrogen containing substrate including a surface region and a strain control region, the strain control region being configured to maintain a quantum well region within a predetermined strain state. The device also has a plurality of quantum well regions overlying the strain control region.

Claims

1. A system comprising:

a laser display; and

a laser device configured to provide light for the laser display, the laser device comprising;

a gallium and nitrogen containing substrate including a surface region and a first lattice constant;

a single or plurality of strained regions acting as an optical confinement region overlying the surface region, the strained region having a second lattice constant, the second lattice constant being larger than the first lattice constant;

a strain control region disposed between or above one or more of the strained regions having a third lattice constant, the third lattice constant being substantially equivalent to the second lattice constant, the strain control region being configured to maintain at least a quantum well region within a predetermined strain state;

a plurality of quantum well regions overlying the optical confinement region, each of the plurality of quantum well regions having a fourth lattice constant, the fourth lattice constant being substantially equivalent to the second lattice constant, whereupon the strain control region has a higher bandgap than the strained region and the quantum well regions.

2. The system of claim 1 wherein:

the strained region comprises an interface region between the substrate and the strain control region; and

the interface region comprises a plurality of dislocations.

3. The system of claim 1 wherein the surface region is configured in a {20-21} semi-polar orientation and the device is a laser diode device, or the surface region is configured to be in an off-set of a {20-21} orientation and the strained region is at least partially relaxed.

4. The system of claim 1 further comprising:

at least one barrier region sandwiched between a pair of quantum well regions;

each of the barrier regions comprising GaN, InGaN, AlGaN, or AlInGaN; and

each of the barrier regions ranges in thickness from 1.5 nm to 12 nm.

5. The system of claim 1 wherein:

the strained region comprises a single layer of InGaN;

the strained region has a thickness ranging from 20 to 80 nm with 2 to 20% InN content;

the strained region is overlaid with a single strain control layer comprised of GaN or AlGaN; and

the strain control layer has a thickness ranging from 2-20 nm with 2 to 40% AlN content.

6. The system of claim 1 wherein:

the strained region comprises multiple layers of GaN, AlN, AlInN, AlGaInN, or InGaN;

the multiple layers have a thickness ranging from 10 to 50 nm with 2 to 25% InN content;

the multiple layers are separated by strain control layers comprises of AlGaN;

the strain control layers have thickness ranging from 2-20 nm with 2 to 40% AlN content.

7. The system of claim 1 wherein:

the strained region comprises multiple layers of InGaN;

the InGaN layers have a thickness ranging from 10 to 50 nm with 2 to 25% InN content;

the InGaN layers are separated by strain control layers comprised of GaN;

there are a plurality of pairs of strained and strain control layers;

the thickness of the strained layers is equal or decreases with each subsequently deposited layer;

the composition of strained layers is equal or increases in InN with each subsequently deposited layer.