Fin Gate Stack Isolation Structure for Leakage Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of forming reliable semiconductor devices at smaller sizes is exacerbated by the complexity of fabrication processes as feature sizes continue to decrease, making it difficult to achieve consistent performance and prevent issues like short circuits and current leakage.
Innovation Solution
A semiconductor device structure is formed with fin structures and metal gate stacks, where a dummy gate stack is removed to create a trench for multiple metal gate stacks, followed by forming recesses to separate these stacks and include isolation elements, enhancing control over the gate stack height and reducing the risk of short circuits and current leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency improves and costs lower, but fabrication process complexity increases and reliability decreases
Solution Approach 1:
The fabrication process is divided into multiple discrete stages: forming isolation structures in recesses, depositing gate dielectric and metal gate layers, and selectively removing portions to create separated gate stacks. This segmentation allows each stage to be optimized independently, managing the complexity of fabrication at smaller feature sizes while maintaining productivity gains from scaling.
2Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency improves and costs lower, but manufacturing reliability worsens due to difficulty in forming consistent devices
Solution Approach 1:
Isolation structures are formed in recesses before the gate stack fabrication process begins. This preliminary action establishes defined boundaries and separation zones that prevent defects and ensure consistent device formation at smaller feature sizes, thereby maintaining reliability while enabling continued scaling for productivity improvements.
3Manufacturing precision
If dummy gate stack is removed to create trench for multiple metal gate stacks, then control over gate stack height improves and short circuit risk reduces, but fabrication process complexity increases
Solution Approach 1:
A dummy gate stack is temporarily formed during fabrication and then selectively removed to create a trench that separates multiple metal gate stacks. This extraction approach enables precise control over gate stack height and spacing while maintaining a relatively streamlined fabrication process, as the dummy structure serves its purpose and is then removed without requiring complex direct formation methods.
Data Source
AI summary
Structures and formation methods of a semiconductor device structure are provided. The semiconductor device structure includes a fin structure over a semiconductor substrate. The semiconductor device structure also includes a gate stack covering a portion of the fin structure, and the gate stack includes a work function layer and a metal filling over the work function layer. The semiconductor device structure further includes an isolation element over the semiconductor substrate and adjacent to the gate stack. The isolation element is in direct contact with the work function layer and the metal filling.