Group 13 Nitride Films via Pulse Sputtering at Low Temperature

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Solution Overview

Problem

Conventional methods for growing group 13 nitride semiconductors, such as the MOCVD method, face challenges in achieving high-quality films with low impurity concentrations and high electron mobility, especially at high donor concentrations.

Innovation Solution

The use of a pulse sputter deposition (PSD) method to form a sputtered single crystal film at low temperatures, allowing for the incorporation of oxygen as an impurity and achieving high electron mobility even at high electron concentrations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the MOCVD method is used for crystal growth, then high temperature processing (exceeding 1000°C) is achieved, but manufacturing complexity and energy consumption increase

Engineering Contradiction:
Improveprocess temperatureVSAvoidenergy consumption
Core Design Contradiction:
TemperatureVSUse of energy by stationary object

Solution Approach 1:

The patent changes the temperature parameter from high (MOCVD exceeding 1000°C) to low (PSD method below 1000°C) while maintaining film quality. This parameter change resolves the contradiction by achieving the desired crystal growth without the high energy consumption associated with high temperature processing.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If the MBE method is used for crystal growth, then low temperature processing is achieved, but manufacturing area size is limited and cost increases

Engineering Contradiction:
Improveprocess temperatureVSAvoidfilm area size
Core Design Contradiction:
TemperatureVSArea of stationary object

Solution Approach 1:

The PSD method is designed to be universally applicable for manufacturing compound semiconductor films across various area sizes. Unlike MBE which is limited to small areas, the PSD method can process both small and large substrate areas, making it a multi-functional solution that resolves the area size limitation while maintaining low temperature processing.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If donors are incorporated at high concentration by MBE method, then electrical conductivity is improved, but transparency decreases due to absorption in the forbidden band

Engineering Contradiction:
Improveelectrical conductivityVSAvoidabsorption loss
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent changes the donor concentration parameter to achieve high electrical conductivity while controlling the absorption effect. By using the PSD method with optimized doping parameters, the patent achieves high electron concentration (1×10^20 to 1×10^21 cm^-3) while maintaining film transparency, resolving the contradiction between conductivity and transparency.

Inventive Principle:
Principle #35Parameter changes

4Ease of manufacture

If conventional methods are used for crystal growth, then manufacturing process is established, but electron mobility is insufficient at high donor concentrations

Engineering Contradiction:
Improvemanufacturing processVSAvoidelectron mobility
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the conventional MOCVD chemical vapor deposition mechanism with a physical sputtering mechanism. This substitution allows for better control of crystal quality and electron mobility at high donor concentrations. The PSD method's physical deposition process enables achieving electron mobility of 50 cm²/Vs or higher even at high electron concentrations, resolving the contradiction between ease of manufacture and electron mobility.

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

The PSD method enables the production of high-quality group 13 nitride semiconductor films with high electron mobility (50 cm^2/V·s or higher) and low specific resistance, suitable for advanced electronic and optoelectronic devices.

Implementation Method 1

a method for manufacturing a compound semiconductor by pulse-sputtering using a group 13 nitride semiconductor

Methodology Applied
Scientific EffectSputtering: Sputtering

Data Source

PatentEP3509088B1Nitride compound semiconductor and method for manufacturing same
Publication Date: 2025.01.29 THE JAPAN SCI & TECH AGENCY
  • EP3509088B1 patent drawingFigure 1
  • EP3509088B1 patent drawingFigure 2(a)~2(b)
  • EP3509088B1 patent drawingFigure 3(a)~3(b)

AI summary

This compound semiconductor constitutes a high-performance semiconductor device by having a high electron concentration of 5×1019 cm-3 or more, and exhibiting an electron mobility of 46 cm2/V·s or more, and low electrical resistance. The present invention provides an n conductivity-type group 13 nitride semiconductor that can be film-formed at a temperature within a range from a room temperature to 700°C on a substrate having a large area.