VCSEL P-Side Oxide Layer Formation for Leakage Control
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Solution Overview
Problem
Vertical cavity surface emitting laser elements face challenges in achieving high insulating properties and longer lifespan due to current confinement layer limitations.
Innovation Solution
A method involving the formation of a nitride semiconductor layer with an n-side and p-side semiconductor layer, followed by reactive ion etching and heat treatment in an oxygen atmosphere with an aluminum or quartz member, to create an oxide layer on the p-side semiconductor layer, enhancing the insulating properties and current confinement region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If ion-implantation method is used to form current confinement layer, then current confinement structure can be created, but insulating property and lifetime are insufficient
Solution Approach 1:
The invention changes the manufacturing parameters by switching from ion-implantation to a combination of reactive ion etching and heat treatment processes. This parameter change enables the formation of an oxide layer with superior insulating properties while extending the element's lifetime, directly resolving the contradiction between reliability and ease of manufacture.
Solution Approach 2:
The invention replaces the mechanical ion-implantation process with a chemical-thermal process involving reactive ion etching followed by heat treatment in an oxygen atmosphere. This substitution creates an oxide layer that provides both high insulating property and extended lifetime, overcoming the limitations of the mechanical implantation method.
2Reliability
If conventional current confinement layer is used, then basic current confinement is achieved, but insulating property remains insufficient
Solution Approach 1:
The invention applies preliminary action by performing reactive ion etching before heat treatment. This preliminary etching step prepares the surface by removing contaminants and creating a uniform starting point, which ensures that the subsequent oxide layer forms with high uniformity and superior insulating properties during the heat treatment process.
Solution Approach 2:
The invention uses strong oxidation conditions by performing heat treatment in an oxygen atmosphere at elevated temperatures (600-800°C). This accelerated oxidation process ensures complete and uniform conversion of the semiconductor layer surface to oxide, achieving high insulating property while maintaining uniform layer formation.
3Reliability
If no heat treatment is performed, then process steps are reduced, but oxide layer quality and insulating property are insufficient
Solution Approach 1:
The invention merges the oxide formation and quality enhancement into a single heat treatment step that follows reactive ion etching. This combined approach ensures that the oxide layer achieves superior quality and insulating properties while minimizing the total number of process steps, as the heat treatment simultaneously completes oxidation and improves layer uniformity.
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 results in improved insulating properties and extended operational life of the vertical cavity surface emitting laser element by forming a uniform oxide layer that reduces current leakage and enhances reliability.
Implementation Method 1
performing reactive ion etching on a portion of the p-side semiconductor layer corresponding to a portion of the upper surface of the nitride semiconductor layer exposed from the mask member
Implementation Method 2
performing, in an oxygen atmosphere, heat treatment on the p-side semiconductor layer
Implementation Method 3
performing, in an oxygen atmosphere, heat treatment on the p-side semiconductor layer
Data Source
AI summary
A method of manufacturing a vertical cavity surface emitting laser element includes: providing a nitride semiconductor layer including an n-side semiconductor layer, an active layer, and a p-side semiconductor layer layered in this order, with the p-side semiconductor layer defining an upper surface of the nitride semiconductor layer; forming a mask member on a portion of the upper surface of the nitride semiconductor layer; placing the p-side semiconductor layer in an oxygen atmosphere together with a member containing aluminum or quartz and performing reactive ion etching on a portion of the p-side semiconductor layer; performing, in an oxygen atmosphere, heat treatment on the p-side semiconductor layer; removing the mask member; and forming an electrode on the upper surface of the nitride semiconductor layer across the portion having been subjected to the reactive ion etching and the portion from which the mask member has been removed.