Nitride Semiconductor Crystal Growth via High-Pressure Trihalide Epitaxy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nitride semiconductor crystal growth techniques, such as THVPE, face limitations in using high-concentration source gases, leading to difficulties in manufacturing large-diameter and thick nitride semiconductor crystals with low impurity concentrations and high growth rates, particularly due to temperature constraints and substrate material differences.
Innovation Solution
The method involves using a trihalide gas with a partial pressure of 9.0×10−3 atm or higher and growing nitride semiconductor crystals at temperatures of 1200°C or higher in the −C-axis direction, optimizing growth conditions to achieve high-quality crystals with diameters of four inches or more and impurity concentrations of 1×10^17/cm^3 or lower.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional THVPE technique is used, then nitride semiconductor crystals can be grown at higher temperatures and rates than HVPE, but high-concentration source gases cannot be used and thus large-diameter and thick crystals cannot be manufactured
Solution Approach 1:
The patent changes the key parameter of source gas concentration from conventional low levels to high concentration (9.0×10^-3 atm or higher partial pressure). This parameter change enables simultaneous achievement of high growth rates and large crystal dimensions, resolving the contradiction between productivity and quantity of substance.
2Quantity of substance
If high-concentration source gases are used, then large-diameter and thick crystals can be manufactured, but conventional techniques do not allow this due to temperature constraints
Solution Approach 1:
The patent raises the growth temperature to 1200°C or higher (for GaN) and 1400°C or higher (for AlN), which are higher than conventional THVPE temperatures. This temperature parameter change enables the use of high-concentration source gases and achieves large crystal dimensions while maintaining crystal quality.
3Manufacturing precision
If conventional THVPE is used, then growth can proceed at moderate temperatures, but impurity concentration cannot be reduced to 1×10^17/cm³ or lower
Solution Approach 1:
The patent employs high growth temperatures (1200°C or higher for GaN, 1400°C or higher for AlN) which thermally activate impurity removal processes. This temperature parameter change enables achievement of ultra-low impurity concentrations (1×10^17/cm³ or lower) that cannot be achieved at conventional moderate temperatures.
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 enables stable growth of nitride semiconductor crystals with improved crystallinity, reduced impurity concentrations, and increased growth rates, overcoming the limitations of existing techniques by allowing for larger diameters and thicker films while maintaining high crystal quality.
Implementation Method 1
Tri-halide vapor phase epitaxy (THVPE) can grow nitride semiconductor crystals at higher temperatures and rates than hydride vapor phase epitaxy (HVPE)
Implementation Method 2
a growth temperature for the GaN crystal is 1200° C. or higher... a growth temperature for the AlN crystal is 1400° C. or higher
Data Source
AI summary
A nitride semiconductor crystal has a diameter of four inches or more and is warped to have a curvature radius of 100 m or more, and has an impurity concentration of 1×1017/cm3 or lower. A manufacturing method for a nitride semiconductor crystal includes providing a substrate, feeding a gallium trihalide gas having a partial pressure of 9.0×10−3 atm or higher onto the substrate, and growing a GaN crystal in the −C-axis direction on the substrate, where a growth temperature for the GaN crystal is 1200° C. or higher, or a manufacturing method for a nitride semiconductor crystal includes providing a substrate, feeding an aluminum trihalide gas having a partial pressure of 9.0×10−3 atm or higher onto the substrate, and growing an AlN crystal in the −C-axis direction on the substrate, where a growth temperature for the AlN crystal is 1400° C. or higher.