# US 6,720,571 B1 · Quantum well device with ESD endurance and method of forming the same

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- Number: US 6,720,571 B1
- Document ID: US6720571B1
- Status: Granted
- Kind: B1
- Application number: 09/643,852
- Filed: 2000-08-22
- Granted: 2004-04-13
- Earliest claimed: 1999-12-02
- Assignees: United Epitaxy Company, Ltd.
- Inventors: Chuan-Cheng Tu; Jen-Chau Wu; Shiu-Mu Tang; Pao-I Huang
- Web page: https://patentgrep.com/patent/US6720571B1

## CPC

- H01S 5/34: comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers (H01S5/36 takes precedence)
- B82Y 20/00: Nanooptics, e.g. quantum optics or photonic crystals
- H01S 5/305: {characterised by the doping materials used in the laser structure}
- H01S 5/3086: {doping of the active layer}
- H01S 5/3407: {characterised by special barrier layers}
- H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES

## Abstract

The present invention provides a quantum well device and a method of forming the same. The quantum well device comprises alternately stacked n layers of quantum well layers and n layers of barrier layers, wherein the quantum well layers and barrier layers are alternatively doped with dopant, and n is a positive integer. The dopant of a predetermined concentration is applied to control the breakdown voltage and output intensity of the quantum well device and to consequently avoid artificial and mechanical ESD failure.

## Claims

### Claim 1

An AlGaInP quantum well device with an electrostatic discharge (ESD) endurance, comprising:
a first conductivity type GaAs substrate;
a first conductivity type GaAs buffer layer formed on the first conductivity type GaAs substrate;
a first conductivity type AlGaInP lower cladding layer formed on the first conductivity type GaAs buffer layer;
an AlGaInP lower confining layer formed on the first conductivity type AlGaInP lower cladding layer;
an active layer with the ESD endurance formed on the AlGaInP lower confining layer, the active layer comprising alternately stacked n layers of AlGaInP quantum well layers and n layers of AlGaInP barrier layers, wherein the AlGaInP quantum well layers are doped with an n-type dopant while the AlGaInP barrier layers are undoped, and n is a positive integer;
an AlGaInP upper confining layer formed on the active layer;
a second conductivity type AlGaInP upper cladding layer formed on the AlGaInP upper confining layer; and
a second conductivity type covering layer formed on the second conductivity type AlGaInP upper cladding layer.

### Claim 2 (depends on 1)

The AlGaInP quantum well device of claim 1, wherein the n-type dopant is selected from a group consisting of Te, Se or Si.

### Claim 3 (depends on 1)

The AlGaInP quantum well device of claim 1, wherein a concentration of the n-type dopant is between 5×1016/c.c. and 3×1018c.c.

### Claim 4

An AlGaInP quantum well device with an electrostatic discharge (ESD) endurance, comprising:
a first conductivity type GaAs substrate;
a first conductivity type GaAs buffer layer formed on the first conductivity type GaAs substrate;
a first conductivity type AlGaInP lower cladding layer formed on the first conductivity type GaAs buffer layer;
an AlGaInP lower confining layer formed on the first conductivity type AlGaInP lower cladding layer;
an active layer with the ESD endurance formed on the AlGaInP lower confining layer, the active layer comprising alternately stacked n layers of AlGaInP quantum well layers and n layers of AlGaInP barrier layers, wherein the AlGaInP quantum well layers are doped with a p-type dopant while the AlGaInP barrier layers are undoped, and n is a positive integer;
an AlGaInP upper confining layer formed on the active layer;
a second conductivity type AlGaInP upper cladding layer formed on the AlGaInP upper confining layer; and
a second conductivity type covering layer formed on the second conductivity type AlGaInP upper cladding layer.

### Claim 5 (depends on 4)

The AlGaInP quantum well device of claim 4, wherein the p-type dopant is selected from a group consisting of Mg, C or Zn.

### Claim 6 (depends on 4)

The AlGaInP quantum well device of claim 4, wherein a concentration of the p-type dopant is between 5×1016/c.c. and 3×1018/c.c.