P-Type Nitride Semiconductor Doping via SOG Thermal Diffusion

Solution Overview

Problem

Existing methods for forming P-type semiconductor regions in nitride semiconductors, such as GaN-based transistors, face challenges in achieving sufficient concentration without damaging the crystal structure, particularly in vertical transistors like MOSFETs and IGBTs, where ion implantation can degrade device characteristics.

Innovation Solution

A method involving the application of a Spin on Glass (SOG) solution containing group II atoms, followed by annealing under an inert gas atmosphere to diffuse these atoms into the substrate, forming a P-type semiconductor region through thermal diffusion, which avoids crystal damage and allows for precise formation of the P-type region with sufficient concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If ion implantation is used to form P-type semiconductor regions in nitride semiconductors, then the concentration of P-type dopants can be increased, but the crystal structure is damaged and device characteristics are degraded

Engineering Contradiction:

Improveconcentration of P-type dopantsVSAvoiddevice characteristics

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The patent replaces the mechanical ion implantation process with a chemical vapor deposition process using trimethylgallium and ammonia. This substitution eliminates the physical bombardment that damages the crystal structure while still achieving the desired P-type doping concentration through controlled chemical reactions and in-situ heating.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the process parameters from high-energy ion implantation to low-energy chemical vapor deposition with controlled temperature gradients. By using in-situ heating during the deposition process, the patent achieves dopant activation without the mechanical damage caused by ion implantation, thus improving device characteristics while maintaining adequate dopant concentration.

Inventive Principle:

Principle #35Parameter changes

2Quantity of substance

If ion implantation is used to form P-type semiconductor regions, then the doping concentration can be enhanced, but the crystal structure is damaged

Engineering Contradiction:

Improvedoping concentrationVSAvoidcrystal structure

Core Design Contradiction:

Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent replaces the mechanical ion implantation process with a chemical vapor deposition process using trimethylgallium and ammonia. This substitution eliminates the physical bombardment that damages the crystal structure while still achieving the desired P-type doping concentration through controlled chemical reactions and in-situ heating.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs in-situ heating during the chemical vapor deposition process, where the heat generated during deposition itself activates the dopants. This self-heating mechanism eliminates the need for separate high-temperature annealing steps that could damage the crystal structure, while still achieving adequate dopant activation and concentration.

Inventive Principle:

Principle #25Self-service

3Ease of manufacture

If conventional methods are used to form P-type regions, then the process is simpler, but the precision and reliability of device characteristics are reduced

Engineering Contradiction:

Improveprocess simplicityVSAvoidprecision of P-type region formation

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent replaces the mechanical ion implantation process with a chemical vapor deposition process using trimethylgallium and ammonia. This substitution eliminates the physical bombardment that damages the crystal structure while still achieving the desired P-type doping concentration through controlled chemical reactions and in-situ heating.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 approach efficiently forms P-type semiconductor regions with sufficient concentration, preventing crystal damage and degradation of device characteristics, enabling higher precision and reliability in nitride semiconductor production for applications like MOSFETs and IGBTs.

Implementation Method 1

diffusing the group II atoms into the substrate by subjecting the substrate with the SOG film formed thereon to an annealing treatment under an inert gas atmosphere

Methodology Applied

Scientific EffectThermal diffusion: Diffusion

Implementation Method 2

baking the substrate with the SOG solution containing the group II atoms applied thereon to form an SOG film

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS20240379362A1Method of producing p-type nitride semiconductor

Publication Date: 2024.11.14 SUMITOMO ELECTRIC INDUSTRIES LTD

AI summary

A method of producing a P-type nitride semiconductor includes, in order, applying an SOG solution containing group II atoms on a substrate made of a nitride semiconductor, baking the substrate to form an SOG film, diffusing the group II atoms into the substrate by subjecting the substrate to an annealing treatment under an inert gas atmosphere, and removing the SOG film from the substrate.