Quantum Cascade Laser Electrode Flattening via Polishing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of quantum cascade laser elements faces challenges in achieving a stable support state and limited wire bonding freedom due to unflattened surfaces of electrodes with embedded ridge portions, which affects heat dissipation and assembly efficiency.
Innovation Solution
A method involving semiconductor substrate preparation, etching to form ridge portions, forming insulating and metal plating layers, and polishing to flatten the electrode surfaces while protecting the cleavage region, ensuring accurate cleavage and enhanced assembly stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the ridge portion is embedded in the first electrode without flattening the surface, then the manufacturing process is simpler, but the support state becomes unstable and wire bonding freedom is limited
Solution Approach 1:
The patent applies preliminary action by performing the flattening process on the first electrode surface before the mounting and wire bonding operations. This ensures that the surface is prepared in advance with the required flatness, enabling stable support state and adequate wire bonding freedom without complicating the overall manufacturing process.
2Reliability
If the surface of the first electrode is flattened by polishing, then the support state and wire bonding freedom improve, but the manufacturing complexity and time increase
Solution Approach 1:
The patent merges the flattening operation with the existing electrode formation process. By integrating the polishing step into the overall electrode manufacturing sequence and utilizing the same processing equipment and parameters, the additional complexity is minimized while achieving the required surface flatness for stable support and wire bonding.
3Reliability
If the surface of the first electrode is flattened by polishing, then the support state and wire bonding freedom improve, but the manufacturing time and cost increase
Solution Approach 1:
The patent optimizes the flattening process parameters including polishing pressure, speed, and duration to achieve the minimum required surface flatness. By carefully controlling these parameters, the process achieves adequate surface quality for stable support and wire bonding while minimizing the time and resources required, thus maintaining manufacturing efficiency.
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 method efficiently manufactures quantum cascade laser elements with flattened electrodes, improving yield rates and enabling stable support and efficient wire bonding, thus addressing the issues of heat dissipation and assembly complexity.
Implementation Method 1
a fourth step of forming a plurality of metal plating layers 520 each of which becomes the first electrode 5 on the plurality of portions 301 each of which becomes the semiconductor laminate 3, and of embedding the ridge portion 30 in each of the plurality of metal plating layers 520
Implementation Method 2
a fifth step of flattening a surface on an opposite side of each of the plurality of metal plating layers 520 from the semiconductor wafer 200 by polishing
Data Source
AI summary
A method for manufacturing a quantum cascade laser element includes: a step of forming a semiconductor layer on a first major surface of a semiconductor wafer; a step of removing a part of the semiconductor layer by etching such that each of portions of the semiconductor layer includes a ridge portion; a step of forming an insulating layer such that at least a part of a surface of the ridge portion is exposed; a step of embedding the ridge portion in each of metal plating layers; a step of flattening a surface of the metal plating layers by polishing in a state where a protective member is disposed; a step of forming an electrode layer on a second major surface of the semiconductor wafer; and a step of cleaving the semiconductor wafer and the semiconductor layer in a state where the protective member is removed.