GaN Cap Layer Cleaning for Flat AlInN LED Epitaxy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for manufacturing nitride semiconductor light-emitting elements face challenges in suppressing threading dislocations and achieving high surface flatness, particularly when growing layers with In on the surface of AlInN layers.
Innovation Solution
A method involving metal organic vapor phase epitaxy (MOVPE) that includes a first layer stacking of AlInN, a cap layer stacking of GaN, and a hydrogen cleaning step before the second layer stacking, which helps in reducing pit density and dislocations by cleaning the surface with hydrogen.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If hydrogen treatment is performed to remove In clusters from AlInN layer surface, then threading dislocation occurrence is suppressed, but pit density increases significantly and surface flatness deteriorates
Solution Approach 1:
A GaN cap layer is introduced as an intermediary between the AlInN layer and the subsequent In-containing layer. This cap layer mediates the interaction by providing a clean GaN surface that prevents direct contact between the In-containing layer and the pit-prone AlInN surface, thereby maintaining both low dislocation density and good surface flatness
Solution Approach 2:
The structure is segmented into distinct layers: AlInN layer, GaN cap layer, and In-containing layer. By dividing the structure and inserting the GaN cap layer, the harmful effects of hydrogen treatment (pit formation) are isolated from the In-containing layer, allowing each layer to perform its specific function without interfering negatively with others
2Reliability
If temperature increasing step is performed to remove In clusters, then threading dislocation occurrence is suppressed, but formation of structure having In layer on AlInN surface becomes difficult
Solution Approach 1:
The GaN cap layer is formed in advance before depositing the In-containing layer. This preliminary action creates a clean, stable surface that enables subsequent low-temperature growth of In-containing structures without requiring high-temperature treatment, thus preventing dislocations while facilitating easy formation of the desired structure
Solution Approach 2:
The invention changes the growth temperature parameter from high temperature (required for temperature increasing treatment) to low temperature (compatible with In layer formation). By using the GaN cap layer, low-temperature growth becomes effective for suppressing dislocations, enabling the formation of In-containing structures that require low growth 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
The method effectively suppresses dislocations and improves surface flatness, enabling the production of nitride semiconductor light-emitting elements with high output and long life.
Implementation Method 1
a hydrogen cleaning step of stopping supply of a raw material gas into a reaction furnace and supplying hydrogen into the reaction furnace to clean at least a surface of the cap layer
Implementation Method 2
A method for manufacturing a nitride semiconductor light-emitting element by metal organic vapor phase epitaxy
Data Source
AI summary
Provided are a method for manufacturing a nitride semiconductor light-emitting element having good quality, and a nitride semiconductor light-emitting element having good quality. A method for manufacturing a nitride semiconductor light-emitting element by metal organic vapor phase epitaxy, the method including: a first layer stacking step of crystal-growing an n-AlInN layer (12) containing Al and In in a composition; a cap layer stacking step of crystal-growing a GaN cap layer (13) containing Ga in a composition on a surface of the n-AlInN layer (12) after performing the first layer stacking step; and a second layer stacking step of crystal-growing a GaN layer (14) containing Ga in a composition on a surface of the GaN cap layer (13) after performing the cap layer stacking step. The method for manufacturing a nitride semiconductor light-emitting element further includes a hydrogen cleaning step of stopping supply of a raw material gas into a reaction furnace and supplying hydrogen into the reaction furnace to clean at least a surface of the GaN cap layer (13), after performing the cap layer stacking step and before performing the second layer stacking step.