Co-doping AlGaN Valency Band Structure for P-type Doping

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

P-type doping of III-V semiconductors like GaN and AlxGa1-xN is challenging due to high activation energy of dopants and low solubility, limiting the efficiency and effectiveness of UV light-emitting diodes.

Innovation Solution

A method involving co-doping with isoelectronic impurities such as arsenic (As) to modify the valency band structure, reducing the ionizing energy of p-type dopants like zinc (Zn), beryllium (Be), or manganese (Mn), enhancing the doping level and carrier concentration in semiconductors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional p-type doping with Mg, Zn, or Be is used in III-V semiconductors, then the doping process is simple, but the activation energy is high (220-550 meV) resulting in low carrier concentration and poor doping efficiency

Engineering Contradiction:

Improvedoping process simplicityVSAvoiddoping efficiency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent introduces isoelectronic impurities (Si, Ge, Sn) as intermediary elements that modify the crystal lattice structure and electronic environment. These intermediaries reduce the activation energy of p-type dopants by altering the valency band structure, enabling more effective charge carrier generation without changing the fundamental doping process

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a composite doping system combining p-type dopants (Mg, Zn, Be) with isoelectronic impurities (Si, Ge, Sn). This composite approach leverages the electron-accepting properties of the p-type dopant while utilizing the lattice-modifying effects of the isoelectronic impurity to reduce activation energy and enhance overall doping efficiency

Inventive Principle:

Principle #40Composite materials

2Quantity of substance

If the dopant concentration is increased to improve carrier concentration, then the doping level increases, but the solubility limit is exceeded causing defects such as gaps, self-interstitial atoms, and antisites

Engineering Contradiction:

Improvecarrier concentrationVSAvoidcrystal defects

Core Design Contradiction:

Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

Isoelectronic impurities act as intermediary elements that occupy lattice sites and modify the local electronic environment. This mediation allows higher dopant concentrations to be incorporated without exceeding the solubility limit, as the intermediaries stabilize the crystal structure and prevent defect formation

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the electronic and structural parameters of the semiconductor lattice by introducing isoelectronic impurities. This parameter modification increases the effective solubility limit of p-type dopants, enabling higher carrier concentrations to be achieved while maintaining crystal integrity and avoiding defect formation

Inventive Principle:

Principle #35Parameter changes

3Productivity

If temperature is increased to improve dopant solubility and activation, then the doping efficiency improves, but the ionizing energy varies considerably and material quality deteriorates

Engineering Contradiction:

Improvedoping efficiencyVSAvoidmaterial quality

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

Isoelectronic impurities serve as thermal mediators that facilitate dopant activation at lower temperatures. By modifying the valency band structure, they enable efficient charge carrier generation without requiring high thermal energy input, thus maintaining material quality while improving doping efficiency

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the electronic band structure parameters through isoelectronic impurity incorporation, which reduces the activation energy required for dopant ionization. This parameter change allows effective doping at moderate temperatures, avoiding the material degradation associated with high-temperature processing

Inventive Principle:

Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method significantly increases the doping level and carrier concentration, improving the efficiency of p-type doping in III-V semiconductors, particularly in AlxGa1-xN alloys, enabling higher performance in UV light-emitting diodes.

Implementation Method 1

a co-doping step with a codopant capable of modifying the structure of the valency band

Methodology Applied

Scientific EffectBand structure modification:

Data Source

PatentUS8367529B2Method for preparing a semiconductor

Publication Date: 2013.02.05 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES

AI summary

The invention concerns a method for preparing a NIII-V semiconductor. According to the invention, the method includes at least one step of doping a semiconductor of general formula AlxGa1-xN, wherein the atomic number x represents the number between 0 and 1 with a p-type electron-accepting dopant, as well as a co-doping step with a codopant capable of modifying the structure of the valency band. The invention also concerns a semiconductor as well as its use in electronics or optoelectronics. The invention further concerns a device as well as a diode using such a semiconductor.