Protective Layer for GAA Transistor Stress Integrity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The integration of a stress layer in gate-all-around (GAA) transistors can lead to damage during the removal of sacrificial layers, degrading the semiconductor structure's performance due to the difficulty in precise etching and the resulting stress layer damage.
Innovation Solution
A protective layer is formed between the sacrificial layer and the stress layer to prevent damage during the removal process, using materials like Si to ensure etching selectivity and compatibility, thereby enhancing the quality and performance of the semiconductor structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stress layer is introduced to improve carrier mobility, then transistor performance is improved, but the stress layer is easily damaged during sacrificial layer removal
Solution Approach 1:
A protective layer is introduced as an intermediary between the sacrificial layer and the stress layer. This protective layer serves as a mediator that prevents direct contact and potential damage between the etching process and the stress layer, while still allowing the stress layer to fulfill its function of improving carrier mobility through crystal lattice mismatch.
Solution Approach 2:
The protective layer is formed before the sacrificial layer removal process. This preliminary action prepares the structure in advance to prevent stress layer damage during the subsequent etching operation, ensuring the stress layer remains intact before the actual damage-risk operation occurs.
2Manufacturing precision
If precise etching is attempted to remove sacrificial layer, then manufacturing precision is improved, but the process becomes more difficult to control
Solution Approach 1:
The protective layer acts as an intermediary that simplifies the etching process. By providing a distinct intermediate layer with different etching characteristics, the process becomes easier to control as the etching can proceed through the protective layer without requiring extremely precise stopping, since the protective layer naturally terminates before reaching the stress layer.
Solution Approach 2:
The protective layer serves as a cushion or buffer zone between the sacrificial layer and the stress layer. This beforehand cushioning allows for less precise etching control because the protective layer absorbs any potential over-etching, preventing damage to the stress layer even if the etching process is not perfectly controlled.
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 protective layer effectively reduces the risk of stress layer damage, improving the quality and performance of the semiconductor structure by maintaining the integrity of the stress layer and enhancing carrier mobility.
Implementation Method 1
using materials like Si to ensure etching selectivity and compatibility
Data Source
AI summary
Semiconductor structure is provided. The semiconductor structure includes at least one fin on a semiconductor substrate; at least one stacked channel layer formed on the at least one fin, each stacked channel layer having a sacrificial layer and a channel layer on the sacrificial layer; a dummy gate structure formed on the dummy gate structure; openings formed in the at least one stacked channel layer at both sides of the dummy gate structure; and a protective layer formed on sidewall surfaces of the sacrificial layer.