Optoelectronic Semiconductor Chip Current Distribution and Moisture Resistance
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Solution Overview
Problem
Conventional optoelectronic semiconductor chips face challenges in maintaining efficiency and longevity due to aging issues, particularly related to current distribution and radiation coupling, which affect homogeneous light emission and resistance to moisture-induced degradation.
Innovation Solution
The semiconductor chip design incorporates a semiconductor layer sequence with a current distribution element on the bottom face and vias that distribute current efficiently, minimizing direct contact with the active layer and using a mirror layer to reduce moisture ingress and enhance radiation coupling, while maintaining low resistance and effective current injection through both top and bottom contacts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If current is injected through the top contact element only, then the device structure is simple, but current distribution is non-uniform leading to non-homogeneous light emission
Solution Approach 1:
The contact structure is segmented into two separate contact elements: a top contact element and a bottom contact element. This segmentation allows current to be injected from both sides of the semiconductor layer sequence, creating a more uniform current distribution through the active layer, which directly resolves the non-uniform light emission issue while maintaining reasonable structural complexity
Solution Approach 2:
The current injection approach is changed from a single-dimensional (top-only) injection to a two-dimensional approach by adding bottom contact elements. This dimensional change enables current to flow through multiple paths and enter the active layer from both top and bottom, achieving homogeneous current distribution and light emission across the device area
2Manufacturing precision
If vias extend through the entire semiconductor layer sequence, then current distribution is improved, but direct contact with the active layer causes moisture-induced degradation
Solution Approach 1:
An insulating material is introduced as an intermediary between the vias and the active layer. This intermediary layer allows the vias to extend through the semiconductor layer sequence for current distribution while preventing direct contact between the metal vias and the active layer, thereby blocking moisture ingress pathways that would otherwise cause degradation of the active layer
Solution Approach 2:
The harmful function of the vias (direct contact with active layer leading to moisture degradation) is extracted and separated from their useful function (current distribution). By removing the direct electrical contact between vias and active layer while maintaining current flow capability through the insulating intermediary, the harmful effect is eliminated while preserving the beneficial current distribution effect
3Productivity
If mirror layer is added to improve radiation coupling, then radiation coupling efficiency is improved, but device complexity increases
Solution Approach 1:
The bottom contact element is designed to serve multiple functions: it acts as both an electrical contact for current injection and as a mirror layer for radiation coupling. This multi-functional design improves radiation coupling efficiency by reflecting light back through the active layer while simultaneously serving as a current injection path, thereby achieving enhanced productivity without proportionally increasing device complexity
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 design enhances the semiconductor chip's resistance to aging by ensuring uniform current distribution, reducing moisture-induced degradation, and improving radiation coupling efficiency, leading to prolonged chip lifespan and consistent performance.
Implementation Method 1
an active layer (12), which is designed to generate electromagnetic radiation. The active layer contains in particular at least one pn-junction
Implementation Method 2
using a mirror layer to reduce moisture ingress and enhance radiation coupling
Implementation Method 3
The top contact element and/or the bottom contact element are preferably each Ohmic conductors and are used for injecting current into the semiconductor layer sequence
Data Source
AI summary
An optoelectronic semiconductor chip is disclosed. In an embodiment the chip includes a semiconductor layer sequence having a bottom face and a top face, wherein the semiconductor layer sequence comprises a first layer of a first conductivity type, an active layer for generating electromagnetic radiation, and a second layer of a second conductivity type and a bottom contact element located at the bottom face and a top contact element located at the top face for injecting current into the semiconductor layer sequence. The chip further includes a current distribution element located at the bottom face, the current distribution element distributes current along the bottom face during operation and a plurality of vias extending from the current distribution element through the first layer and through the active layer into the semiconductor layer sequence, wherein the vias are not in direct electrical contact with the active layer.