P-type Group III Nitride Semiconductor Production Method
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Solution Overview
Problem
Existing methods for producing p-type Group III nitride semiconductors struggle to achieve both high yield and satisfactory device characteristics, often resulting in low reverse voltage and increased operation voltage due to hydrogen passivation and subsequent dehydrogenation techniques, which compromise crystallinity and productivity.
Innovation Solution
A method involving immediate post-growth transition to an inert gas atmosphere with reduced nitrogen source flow rate and cessation of nitrogen source supply during temperature lowering, specifically at 700 to 950°C, to manage hydrogen concentration and maintain high reverse voltage without elevating operation voltage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heat treatment is used to remove hydrogen from the semiconductor, then carrier concentration is improved, but nitrogen is removed simultaneously reducing crystallinity and reverse voltage
Solution Approach 1:
The invention changes the atmospheric parameters during cooling from hydrogen-containing atmosphere to hydrogen-free atmosphere, which alters the chemical environment to prevent hydrogen-dopant bonding while avoiding nitrogen loss through controlled parameter transition
Solution Approach 2:
The invention employs a hydrogen-free atmosphere (inert environment) during the cooling process to prevent hydrogen from bonding with p-type dopants, thereby maintaining carrier concentration without the harmful side effects of heat treatment
2Reliability
If electron beam irradiation is used to activate p-type dopant, then carrier concentration is improved, but treatment time increases and productivity decreases
Solution Approach 1:
The invention replaces the mechanical/electrical process of electron beam irradiation with a chemical atmosphere control process during cooling, achieving dopant activation through environmental control rather than energy beam processing
Solution Approach 2:
The invention integrates the dopant activation process into the continuous cooling operation, eliminating the need for separate post-growth treatment steps and maintaining continuous production flow
3Reliability
If hydrogen-free atmosphere is used during cooling, then carrier concentration is improved, but operation voltage increases due to heat
Solution Approach 1:
The invention optimizes the temperature parameter during the atmosphere transition, performing the switch at a specific temperature point that balances dopant activation with minimizing thermal effects on operation voltage
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 effectively produces p-type Group III nitride semiconductors with high reverse voltage and low operation voltage, ensuring high yield and reproducibility while preventing heat-induced increases in operation voltage.
Implementation Method 1
hydrogen molecules, hydrogen radicals, and atomic hydrogen, which are formed through decomposition of hydrogen gas (serving as a carrier gas for conveying source compounds to a substrate) or ammonia (NH3) serving as a nitrogen source
Implementation Method 2
These hydrogen species are incorporated into a Group III nitride semiconductor crystal layer, during the growth thereof, and bond to a p-type dopant added to the crystal during cooling of the crystal layer from a growth temperature
Implementation Method 3
when the semiconductor sample is irradiated with an electron beam or heated, bonds between hydrogen and the p-type dopant are cleaved, thereby removing hydrogen from the crystal, whereby the p-type dopant can be activated
Implementation Method 4
a Group III nitride semiconductor material is grown on a substrate made of an oxide crystal such as a sapphire single crystal, or a Group III-V compound single crystal, through a method such as metal-organic chemical vapor deposition (MOCVD)
Data Source
AI summary
An object of the present invention is to provide a method for producing a p-type Group III nitride semiconductor which can be used to produce a light-emitting device exhibiting a low operation voltage and a sufficiently high reverse voltage.The inventive method for producing a p-type Group III nitride semiconductor comprises, during lowering temperature after completion of growth of a Group III nitride semiconductor containing a p-type dopant,immediately after completion of the growth, starting, at a temperature at which the growth has been completed, supply of a carrier gas composed of an inert gas and reduction of the flow rate of a nitrogen source; andstopping supply of the nitrogen source at a time in the course of lowering the temperature.