Edge-Emitting Laser Cleaving Without Metal Layers on Streets
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Solution Overview
Problem
The manufacturing of edge-emitting lasers is hindered by microstep defects and metallic contamination on the output facet, particularly when cleaving short cavity lasers, which affects the burn-in yield and long-term reliability.
Innovation Solution
Cleaving a semiconductor wafer along streets formed without dielectric and metal layers, followed by depositing a dielectric material on the remaining street portions to create defect-free and contamination-free cleaved facets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the semiconductor wafer is cleaved along streets with metal and dielectric layers present, then the structural integrity is maintained, but microstep defects and metallic contamination occur on the output facet
Solution Approach 1:
The patent removes the metal and dielectric layers from the street regions before the cleaving process. This extraction prevents these layers from interfering with the cleave, eliminating the source of microstep defects and metallic contamination on the output facet, thereby achieving defect-free cleaved facets while maintaining structural integrity where layers are retained on the laser cavities.
Solution Approach 2:
The patent performs the removal of metal and dielectric layers from the streets as a preliminary step before cleaving. By preparing the streets in advance to be free of contaminating layers, the subsequent cleaving process produces defect-free output facets without requiring post-cleaving cleaning or repair operations.
2Productivity
If the cleaving process is performed on short cavity lasers, then high-power laser applications are enabled, but the output facet becomes more susceptible to microstep defects and contamination
Solution Approach 1:
For short cavity lasers, the patent extracts the metal and dielectric layers from the street regions before cleaving. This removal is particularly critical for short cavity lasers because their smaller size makes them more vulnerable to the relative impact of cleaving defects. By eliminating the contaminating layers in advance, the output facets achieve the required quality for high-power applications.
Solution Approach 2:
The patent applies preliminary preparation of the streets by removing metal and dielectric layers before the cleaving process for short cavity lasers. This advance preparation ensures that when these vulnerable, small-sized lasers are cleaved, the output facets remain free from microstep defects and metallic contamination, enabling their use in demanding high-power applications.
3Reliability
If metal layers are present during cleaving, then electrical contacts are established, but metallic contamination deposits on the output facet
Solution Approach 1:
The patent segments the wafer structure by creating street regions where metal and dielectric layers are removed, separating these areas from the laser cavity regions where layers are retained for electrical contacts. This spatial segmentation allows electrical contacts to be established on the cavities while preventing metal contamination from reaching the output facets during cleaving.
Solution Approach 2:
The patent extracts metal and dielectric layers specifically from the street regions while retaining them on the laser cavities. This selective extraction ensures that electrical contacts remain intact on the cavities for proper electrical functionality, while the absence of metal layers in the street regions prevents metallic contamination from depositing on the output facets during the cleaving process.
Data Source
AI summary
Methods of manufacturing edge-emitting lasers include cleaving a semiconductor wafer along one or more streets formed on the wafer. A street is an extended region formed without dielectric and metal layers and may be formed on the semiconductor wafer, for example, by a selective wet etching process or a dry etching process. Cleaving along the street(s) without dielectric and metal layers achieves cleaved facets, which are substantially free from microstep defects and metal contamination. After cleaving, a dielectric material may be provided on the remaining street portions along the ends of the cleaved facets, for example, by intentional overspray deposition of facet coatings.