Semiconductor Photon Absorption Seed Layer for Dislocation Reduction
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Solution Overview
Problem
The formation of semiconductor layers with fewer crystal defects is challenging due to lattice constant differences between materials, leading to defects at interfaces, which affects the performance of semiconductor devices like photodetectors.
Innovation Solution
A semiconductor device structure and method that includes a substrate with a photon absorption seed layer and a photon absorption layer, where the seed layer is crystallized in a specific manner to reduce dislocation density, using a lateral melt growth method and epitaxial growth to form a substantially single-crystalline photon absorption layer with minimized defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If epitaxial growth is used to form semiconductor layers with different materials, then the functionality and material diversity of the device is improved, but crystal defects occur at interfaces due to lattice constant differences
Solution Approach 1:
A photon absorption seed layer is introduced as an intermediary between the substrate and the photon absorption layer. This seed layer has a lattice constant that is intermediate between the substrate and the photon absorption layer materials, serving as a transition layer that reduces lattice mismatch and prevents dislocation propagation to the final device layer.
Solution Approach 2:
The photon absorption structure is segmented into multiple layers: a substrate, a photon absorption seed layer with intermediate lattice constant, and a photon absorption layer. This segmentation allows each layer to be optimized independently, with the seed layer specifically designed to mitigate interface defects.
2Manufacturing precision
If a seed layer with intermediate lattice constant is introduced, then dislocation density in the photon absorption layer is reduced, but the device structure becomes more complex
Solution Approach 1:
The seed layer's thickness and composition are carefully controlled within specific ranges. The thickness is optimized to be sufficient to block dislocations (typically 1-10 micrometers) but not so thick as to create unnecessary complexity or cost. The lattice constant of the seed layer material is selected to be intermediate between substrate and photon absorption layer.
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 significantly reduces crystal defects in the photon absorption layer, improving the reactivity and sensitivity of photodetectors by minimizing lattice mismatch-induced dislocations and enhancing electrical and optical characteristics.
Implementation Method 1
a photon absorption seed layer formed on the first insulation layer in the first region and on the substrate in a second region separate from the first region
Implementation Method 2
the second semiconductor pattern is formed of a lattice structure having a second lattice constant different from the first lattice constant; and a dislocation density of the lattice structure of the second semiconductor pattern at the first region is lower than a dislocation density of the lattice structure of the second semiconductor pattern at the second region
Implementation Method 3
a photon absorption layer formed on the photon absorption seed layer in the first region
Data Source
AI summary
A semiconductor device includes a substrate, a first insulation layer formed on the substrate in a first region, a photon absorption seed layer formed on the first insulation layer in the first region and on the substrate in a second region separate from the first region, and a photon absorption layer formed on the photon absorption seed layer in the first region. The photon absorption seed layer has a particular structure that may assist in reducing dislocation density in a region that includes a photon absorption layer.