Surface-Emitting Laser Passivation for Humidity Resistance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Surface-emitting laser devices are susceptible to humidity, leading to reliability issues and reduced service life, despite existing countermeasures.
Innovation Solution
A manufacturing method for surface-emitting laser arrays involves passivation processing to form a stable oxide film on the outermost front surfaces of the lower semiconductor DBR, preventing water penetration and improving humidity resistance, which includes heat treatment in a nitrogen or oxygen atmosphere to create a thin, adherent oxide film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional countermeasures against humidity are implemented, then some protection is provided, but demanded reliability cannot be obtained
Solution Approach 1:
The patent applies preliminary action by performing passivation treatment on the AlAs layer before final device assembly and sealing. The oxidized constriction structure is formed in advance during manufacturing, creating a stable oxide layer that prevents future humidity-related degradation. This proactive approach addresses humidity susceptibility before it can cause reliability issues during device operation.
Solution Approach 2:
The patent utilizes an oxidizing atmosphere during the passivation process to convert the AlAs layer into a stable oxide layer. This controlled chemical environment transforms the humidity-vulnerable AlAs into oxidation-resistant Al2O3, creating an inert protective barrier that prevents water penetration and maintains device reliability in humid conditions.
2Productivity
If the AlAs layer is selectively oxidized to form constriction structure, then current inflow efficiency is improved, but the device becomes more susceptible to water penetration
Solution Approach 1:
The patent applies the blessing in disguise principle by intentionally oxidizing the AlAs layer, which initially creates water penetration pathways, into a beneficial protective oxide layer. The same oxidation process that forms the constriction structure also creates Al2O3, which serves as a moisture barrier. This converts the potential harm of oxidation into a beneficial protective effect, maintaining both current efficiency and humidity resistance.
Solution Approach 2:
The patent changes the chemical state of the AlAs layer from reduced to oxidized form. By controlling the oxidation process parameters (temperature, time, atmosphere), the AlAs is transformed into Al2O3 with different physical and chemical properties - specifically, improved resistance to water penetration while maintaining the electrical constriction function needed for current efficiency.
3Object-affected harmful factors
If passivation processing is performed to form oxide film, then humidity resistance is improved, but manufacturing process complexity increases
Solution Approach 1:
The patent merges the passivation process with the existing oxidized constriction structure formation process. Instead of adding a separate passivation step, the oxidation conditions are optimized to simultaneously create both the electrical constriction function and the moisture protective oxide layer. This integration reduces manufacturing complexity while achieving dual functionality.
Solution Approach 2:
The oxidized AlAs layer serves multiple functions: it provides electrical current constriction for efficient carrier injection and simultaneously acts as a protective moisture barrier through the formed Al2O3 layer. This multi-functionality eliminates the need for separate passivation structures, simplifying the overall device design and manufacturing process while improving humidity resistance.
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 enhances the reliability and service life of surface-emitting laser arrays by preventing water penetration and oxidation, significantly improving their resistance to high-temperature and high-humidity conditions.
Implementation Method 1
heat treatment in a nitrogen or oxygen atmosphere to create a thin, adherent oxide film
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A manufacturing method for manufacturing a surface-emitting laser device includes the steps of forming a laminated body in which a lower reflecting mirror, a resonator structure including an active layer, and an upper reflecting layer having a selective oxidized layer are laminated on a substrate; etching the laminated body to form a mesa structure having the selective oxidized layer exposed at side surfaces thereof; selectively oxidizing the selective oxidized layer from the side surfaces of the mesa structure to form a constriction structure in which a current passing region is surrounded by an oxide; forming a separating groove at a position away from the mesa structure; passivating an outermost front surface of at least a part of the laminated body exposed when the separating groove is formed; and coating a passivated part with a dielectric body.