Dielectric Liner Structure for GAA FinFET Spacer Void Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenges in semiconductor manufacturing include issues such as voids or seams in spacer structures, reduced formation windows for metal gates, and non-uniformity of nanosheets/nanowires in gate-all-around fin field effect transistors (GAA finFETs), which affect gate control and device performance.
Innovation Solution
The introduction of a dielectric liner between stacked fin structures and spacer structures, along with a semiconductor liner, to prevent over-etching and improve the formation window of metal gates, while enhancing the uniformity of semiconductor layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a dielectric liner is introduced between stacked fin structures and spacer structures, then the formation window of metal gates and spacer structures is improved and voids/seams are reduced, but the device complexity increases
Solution Approach 1:
A dielectric liner is introduced as an intermediary layer between the stacked fin structures and spacer structures. This liner acts as a mediator that prevents direct contact between these components, thereby eliminating voids and seams at their interface while improving the formation window for metal gate and spacer structure fabrication.
Solution Approach 2:
The interface region between stacked fin structures and spacer structures is segmented by introducing a separate dielectric liner layer. This segmentation isolates potential defect formation zones and allows independent optimization of each component's fabrication process, thereby improving overall manufacturing precision.
2Manufacturing precision
If a dielectric liner is introduced to prevent over-etching and improve formation window, then the uniformity of nanosheets/nanowires is enhanced, but the manufacturing process complexity increases
Solution Approach 1:
The dielectric liner is formed in advance before the spacer structures and metal gates are fabricated. This preliminary action establishes a protected interface that prevents over-etching during subsequent processing steps, thereby ensuring uniformity of nanosheets and nanowires throughout the manufacturing process.
Solution Approach 2:
The dielectric liner serves as a protective cushioning layer that is placed beforehand between the stacked fin structures and spacer structures. This liner cushions against potential damage from over-etching and provides a stable foundation for subsequent processing, thereby enhancing the uniformity of critical semiconductor layers.
3Reliability
If the dielectric liner prevents over-etching during isolation layer formation, then the gate control is improved, but the number of manufacturing steps increases
Solution Approach 1:
The dielectric liner acts as a mediator during the isolation layer formation process, preventing the etching process from extending too deeply. This intermediary protection ensures that the gate structure maintains proper control over the channel region while avoiding damage to underlying layers.
Data Source
AI summary
The present disclosure describes a semiconductor structure with a dielectric liner. The semiconductor structure includes a substrate and a fin structure on the substrate. The fin structure includes a stacked fin structure, a fin bottom portion below the stacked fin structure, and an isolation layer between the stacked fin structure and the bottom fin portion. The semiconductor structure further includes a dielectric liner in contact with an end of the stacked fin structure and a spacer structure in contact with the dielectric liner.