SOI Substrate Cleavage in Buffer Layer to Avoid Implantation Defects
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional semiconductor-on-insulator (SOI) substrate manufacturing processes face challenges in minimizing defects and contamination from implantation species and sacrificial layers, which can affect the quality of the SOI substrate and devices formed on it.
Innovation Solution
A method involving the formation of a cleavage plane in a buffer layer using implantation species like hydrogen ions, followed by removal of the sacrificial layer and subsequent dielectric layer formation to avoid implantation-induced defects and contamination, with wafer bonding and splitting processes to create a high-quality SOI substrate with a dielectric-to-dielectric interface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If implantation species are used to form cleavage plane in buffer layer, then wafer splitting can be achieved, but implantation-induced defects and contamination occur
Solution Approach 1:
The harmful implantation species are extracted and removed from the buffer layer through chemical etching processes. The buffer layer is selectively etched away to expose the cleavage plane and remove contaminated regions, separating the harmful implanted ions from the final SOI substrate structure.
Solution Approach 2:
The implantation of hydrogen ions to create the cleavage plane is performed as a preliminary action before final substrate formation. This allows the cleavage plane to be formed and subsequently used for wafer splitting, while the implanted region is then removed to eliminate contamination in the final product.
2Ease of manufacture
If sacrificial layer is used in SOI substrate formation, then wafer bonding can be achieved, but contamination from sacrificial layer remains
Solution Approach 1:
The sacrificial layer is completely removed through selective chemical etching processes. The etch solutions are designed to selectively dissolve the sacrificial layer material while leaving the SOI substrate layers intact, thereby extracting the source of contamination before final substrate completion.
Solution Approach 2:
The sacrificial layer serves as an intermediary element that enables wafer bonding during manufacturing but is then removed. It acts as a temporary mediator that facilitates the bonding process and is subsequently discarded to prevent contamination in the final product.
3Productivity
If conventional SOI substrate manufacturing is used, then production can proceed, but substrate recycling is limited due to defects
Solution Approach 1:
The buffer layer containing implantation defects is discarded through selective removal, while the defect-free SOI substrate layers are recovered and retained for device fabrication. This separation allows the valuable substrate layers to be reused without the contamination from the buffer layer region.
Solution Approach 2:
The substrate structure is segmented into distinct functional layers: the buffer layer containing implantation defects is separated and removed, while the active device layer and carrier substrate are segmented and retained for recycling. This segmentation enables selective recovery of high-quality substrate materials.
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 minimizes defects and contamination, enhances the quality of the SOI substrate, and improves device performance by avoiding implantation-induced issues and allowing for substrate recycling, thereby reducing fabrication costs and increasing substrate reuse.
Implementation Method 1
forming a cleavage plane in the buffer layer using implantation species like hydrogen ions
Implementation Method 2
performing a splitting process along the cleavage plane in the buffer layer
Data Source
AI summary
A method of forming a semiconductor-on-insulator (SOI) substrate includes: forming a first dielectric layer on a first substrate; forming a buffer layer on a second substrate; forming a semiconductor cap on the buffer layer over the second substrate; forming a cleavage plane in the buffer layer; forming a second dielectric layer on the semiconductor cap after forming the cleavage plane; bonding the second dielectric layer on the second substrate to the first dielectric layer on the first substrate; performing a splitting process along the cleavage plane in the buffer layer; removing a first split buffer layer from the semiconductor cap; and removing a second split buffer layer from the second substrate.