Donor Substrate Cavity Segmentation for 3D Integrated Structure Transfer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for manufacturing semiconductor-on-insulator 3D structures face challenges such as high production costs, damage to electronic devices during ion implantation, limited thickness of transferred layers, and the inability to reuse donor substrates, which restrict the feasibility and efficiency of layer transfer processes.
Innovation Solution
A method involving a semiconductor substrate with cavities and partitions, where atomic species are implanted to form zones of weakness, allowing for the transfer of thick active layers onto a receiver substrate while preserving electronic device integrity and enabling substrate reuse, through a process that includes selective etching, trench formation, and thermal annealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If ion implantation is carried out at great depth to transfer thick layers, then the thickness of transferred layer is improved, but the production time increases significantly
Solution Approach 1:
The patent divides the donor substrate into multiple thinner layers, each capable of being transferred independently through ion implantation. This segmentation allows the use of standard ion implantation depths while still achieving the transfer of thick overall structures through multiple sequential transfers, thereby reducing production time compared to attempting to transfer a single thick layer.
Solution Approach 2:
The patent creates preliminary weakening zones within the donor substrate at standard ion implantation depths before the actual transfer process. These pre-created zones facilitate easier and faster detachment during transfer, reducing the time required for the transfer operation itself while enabling the accumulation of thick layered structures through multiple transfers.
2Length of stationary object
If high energy ion implantation is used to achieve deep detachment, then the thickness of transferred layer is improved, but the quantity of ions required increases
Solution Approach 1:
The patent segments the total thickness requirement into multiple thinner transferable layers. Each layer can be detached using standard ion implantation doses at appropriate depths, avoiding the need for high-energy implantation that would require excessively large ion quantities to achieve the same effective detachment depth.
Solution Approach 2:
The patent introduces intermediate donor substrates with cavities that serve as temporary holding structures. These intermediaries allow the accumulation of thick structures through multiple transfers of thinner layers, each created with standard ion implantation quantities, rather than requiring a single high-energy implantation event.
3Ease of manufacture
If ion implantation is performed on the active face containing electronic devices, then the layer transfer is achieved, but damage to electronic devices occurs
Solution Approach 1:
The patent inverts the conventional approach by creating the weakening zones in the donor substrate before transferring the active layer, rather than implanting through the active face. The ion implantation is directed at the backside or lateral surfaces of the donor substrate, creating subsurface weakening zones that enable detachment without exposing the electronic devices on the active face to damaging ion radiation.
Solution Approach 2:
The patent uses intermediate donor substrates with cavities as mediators in the transfer process. These intermediaries allow the creation of weakening zones away from the active face, protecting electronic devices from direct ion exposure while still enabling the transfer of the active layer containing the devices.
4Productivity
If the donor substrate is reused for multiple transfers, then production cost is reduced, but the mechanical integrity of the substrate must be maintained
Solution Approach 1:
The patent segments the donor substrate structure into a reusable base substrate and transferable active layers. The base substrate with its cavity structure is designed to withstand multiple transfer cycles, while the active layers are created and transferred separately. This segmentation allows the robust base to be reused while the thinner active layers are discarded after transfer, maintaining mechanical integrity throughout the process.
Solution Approach 2:
The patent creates preliminary weakening zones at controlled depths that enable clean detachment of active layers while preserving the integrity of the donor substrate base. This preliminary structuring allows the donor substrate to be reused for multiple transfers without compromising its mechanical strength, as the weakening zones are created fresh for each transfer cycle at appropriate depths.
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 allows for the efficient transfer of thick active layers with minimal damage, enabling the reuse of donor substrates and reducing production costs, while maintaining the mechanical and electrical properties of electronic devices, thus overcoming the limitations of existing techniques.
Implementation Method 1
implantation of atomic species through the regions of the active layer exposed by the mask, to form a zone of weakness in each partition
Implementation Method 2
detachment of the donor substrate along the zones of weakness in order to transfer at least part of the active layer onto the receiving substrate
Data Source
Figure 1~4
Figure 5~6
Figure 7~8
AI summary
The invention relates to a method for producing a donor substrate (20) for creating a three-dimensional integrated structure (40), comprising the following steps: - providing a semiconductor substrate (10) comprising a surface layer (14), called active layer, and a layer (11) comprising a plurality of cavities (12) extending under the active layer, each cavity (12) being separated from an adjacent cavity by a partition (13), - forming an electronic device (15) in a region (14A) of the active layer (14) situated plumb with a cavity (12), - depositing a protective mask (17) on the active layer (14) so as to cover said electronic device (15) while at the same time exposing a region (16) of the active layer situated plumb with each partition (13), implanting atomic species through regions of the active layer that are exposed by the mask, so as to form a weakened zone (19) in each partition (13).