Semiconductor Light Emitting Device Tapered Separation
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Solution Overview
Problem
Conventional semiconductor light emitting devices face issues with damage and peeling off of the semiconductor layer during separation, leading to reduced light emitting efficiency and potential corrosion of the joint metal layer due to mechanical forces and chemical exposure.
Innovation Solution
A semiconductor light emitting device design where the joint metal layer is sandwiched between the bonding metal layer and the semiconductor layer, with a stopper film like Ni or silicon-based layers to prevent exposure and corrosion, and a tapered shape for the semiconductor layer to minimize mechanical stress and chemical reaction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the semiconductor layer is separated into chip-shaped devices using mechanical force, then the device can be manufactured in batches, but the mechanical force causes damage and peeling off of the semiconductor layer and passivation film
Solution Approach 1:
The patent applies preliminary action by forming a tapered shape at the lower end of the semiconductor layer before the separation process. This pre-formed geometry reduces mechanical stress concentration during subsequent dicing operations, preventing film peeling and damage while enabling batch manufacturing. The tapered configuration is created in advance through selective etching or growth processes, so that when mechanical separation occurs, the stress is distributed more evenly along the tapered interface rather than concentrating at a sharp boundary.
2Ease of manufacture
If the joint metal layer is exposed during separation, then the separation process can be completed, but the exposed joint metal layer becomes corroded
Solution Approach 1:
The patent introduces a stopper film as an intermediary protective layer between the joint metal layer and the external environment. This stopper film, positioned at the lower end of the joint metal layer, acts as a barrier that prevents corrosive substances from reaching and attacking the metal layer during and after the separation process. The stopper film is specifically designed to be corrosion-resistant and is formed to extend beyond the joint metal layer boundaries, ensuring complete protection even when the structure is separated into individual chips.
3Ease of manufacture
If a dicing street is formed by selectively removing GaAs layer, then separation is facilitated, but mechanical force still causes peeling off of passivation film at the side face of joint metal layer
Solution Approach 1:
The patent employs composite material structures by combining multiple layers with different properties: the semiconductor layer, passivation film, joint metal layer, and stopper film are formed as a composite structure. The stopper film is specifically selected as a material that is both mechanically strong and chemically inert, providing dual functionality. This composite approach allows the structure to withstand mechanical separation forces while the stopper film component specifically protects the joint metal layer interface, preventing passivation film peeling that occurs in conventional single-material structures.
Data Source
AI summary
According to one embodiment, in a semiconductor light emitting device, a first electrode is provided on a first surface of the semiconductor laminated body including a light emitting layer. A joint metal layer is provided on a second surface of the semiconductor laminated body opposed to the first surface of the semiconductor laminated body. A bonding metal layer covers a first surface of the joint metal layer on a side opposite to the semiconductor laminated body and is provided on a side of the second surface of the semiconductor laminated body. A substrate provided with a second electrode is bonded to the bonding metal layer. A layer having an etching resistance property to an etchant for etching the semiconductor laminated body is formed on a side of the surface of the bonding metal layer facing to the semiconductor laminated body.