Seed Layer for Uniform III-V Active Layer Growth on Semiconductor Islands
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Solution Overview
Problem
III-V semiconductor devices, such as light-emitting diodes, face challenges in achieving uniform thickness of active layers on single-crystal semiconductor islands due to non-reactivity with dielectric layers, leading to uneven growth and reduced useful surface area.
Innovation Solution
A structure with a seed layer of polycrystalline AlN deposited between single-crystal semiconductor islands on a dielectric layer, preventing species migration and ensuring uniform active layer growth by providing chemical affinity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dielectric layer is used as the substrate for single-crystal semiconductor islands, then the islands can be formed and relaxed without excessive buckling, but the active layer species migrate to the edges of the islands due to non-reactivity with the dielectric layer, resulting in non-uniform thickness
Solution Approach 1:
A seed layer made of a III-N material is introduced between the dielectric layer and the single-crystal semiconductor islands. This seed layer acts as an intermediary that provides chemical affinity for the active layer species (III-V materials), preventing their migration to the island edges. The seed layer is specifically designed to be reactive with the active layer species while the dielectric layer remains chemically inert, thus solving the uniformity problem without compromising the structural benefits of the dielectric substrate.
2Area of stationary object
If the dimensions of the islands are increased to compensate for the unusable peripheral area, then the useful surface area increases, but the relaxation of the islands becomes excessive and causes buckling
Solution Approach 1:
The seed layer enables the use of larger island dimensions by providing the necessary chemical affinity at the interface. This allows the islands to be made larger to increase useful surface area while maintaining proper adhesion and preventing excessive relaxation-induced buckling, as the seed layer mediates the stress distribution and chemical bonding.
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
The seed layer ensures uniform thickness and prevents species migration, enhancing the useful surface area for semiconductor device fabrication.
Implementation Method 1
A structure with a seed layer of polycrystalline AlN deposited between single-crystal semiconductor islands on a dielectric layer, preventing species migration and ensuring uniform active layer growth by providing chemical affinity
Implementation Method 2
the single-crystal semiconductor islands are formed in a continuous film of materials to release the stress originally present in this film by deformation during a relaxation treatment
Data Source
AI summary
A structure that can be used to manufacture at least one active layer made of a III-V material thereon includes a substrate comprising a carrier having a main face, a dielectric layer located on the main face of the carrier, and a plurality of single-crystal semiconductor islands located directly on the dielectric layer. The islands have an upper surface in order to serve as a seed surface for the growth of the active layer. The structure further comprises a seed layer located between the single-crystal semiconductor islands, directly on the portion of the dielectric layer that is not covered by the islands, without masking the upper surface of the islands, so that the dielectric layer is not exposed to the external environment.