Laser Diode Wafer Shadowing for Contact Layer Deposition
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Solution Overview
Problem
The existing methods for producing laser diodes are complex and time-consuming, particularly due to the challenging connection and precise adjustment of laser diodes to carrier elements, which involves expensive machine and bonding processes.
Innovation Solution
The method involves depositing a laser-diode structure on a wafer piece, allowing for integral manufacturing of the laser diode with the carrier element, simplifying the process by using shadowing effects of mounts to deposit mirror and contact layers, and thinning the wafer before cleaving it into pieces, thereby avoiding complex adjustments and expensive processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If laser diodes are connected to carrier elements using conventional bonding processes, then reliable electrical and optical connection is achieved, but manufacturing complexity and production time increase significantly
Solution Approach 1:
The patent merges the laser diode structure and carrier element into a single integrated component. The laser diode is grown directly on the carrier element using epitaxial techniques, eliminating the need for separate bonding processes. This integration maintains reliable electrical and optical connections while dramatically simplifying manufacturing procedures and reducing production time.
2Manufacturing precision
If precise adjustment of laser diode relative to carrier element is performed using conventional methods, then optimal optical alignment is achieved, but adjustment difficulty and cost increase
Solution Approach 1:
The patent performs preliminary alignment during the epitaxial growth process itself. The laser diode structure is grown with predetermined geometric relationships to the carrier element, establishing precise optical alignment before any separate adjustment steps are needed. This preliminary positioning eliminates complex post-growth adjustment operations while maintaining optimal alignment precision.
3Productivity
If wafer is thinned to very thin dimensions before cleaving, then cleaving speed increases, but wafer strength decreases and handling becomes difficult
Solution Approach 1:
The patent optimizes the wafer thinning parameters by controlling the epitaxial growth thickness and substrate removal depth to achieve an intermediate thickness range. This parameter optimization balances wafer strength for handling with cleaving efficiency, allowing fast mechanical cleaving without compromising wafer integrity during processing.
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 results in a cost-effective and precise production of laser diodes with reduced manufacturing complexity, enabling precise alignment and eliminating the need for expensive machine and bonding processes, facilitating the integration of optical components like optical fibers.
Implementation Method 1
mounts which shadow different areas of the front face of the wafer piece, the mirror layer and the contact layer being deposited on different areas of the front face of the wafer piece by utilizing the shadowing effects of the mounts
Implementation Method 2
the mirror layer and/or the contact layer are deposited, particularly by vapour deposition, onto the wafer pieces' front face at a predetermined angle in a slanted manner with regard to the covering elements of the first and/or the second mount by means of a directed deposition technique
Data Source
AI summary
In a method for producing a laser diode, a number of laser diodes are produced on a wafer. The wafer is broken down into wafer pieces, each wafer piece having a plurality of laser diodes being arranged side by side. One wafer piece is inserted into a first mount that includes a first covering element overlapping a front face of the wafer piece and shadowing a bottom area of the front face of the wafer piece. A minor layer is deposited on an unshadowed upper area of the wafer piece's front face. The wafer piece is inserted into a second mount, which includes a second covering element that shadows the minor layer of the upper area of the front face. An electrically conductive contact layer is deposited on an unshadowed bottom area of the wafer piece's front face. The wafer piece is subsequently broken down into individual laser diodes.