Semiconductor Contact Structure With Rounded Isolation Corners
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing of memory cell contacts in semiconductor structures faces challenges due to the shrinking sizes, particularly in forming contacts with sharp corners that can lead to short circuits.
Innovation Solution
A semiconductor structure is developed with a dielectric layer stack, an isolation structure, and a lining layer, where the lining layer is formed in the sharp corners between the isolation structures and the dielectric layer stack, creating round corners for the contacts to prevent them from extending through sharp corners and connecting with each other, thereby reducing the possibility of short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If contacts are formed with sharp corners to fit the isolation structure, then the contact geometry matches the structure, but short circuits occur between adjacent contacts
Solution Approach 1:
The patent applies curvature by forming round corners on the contact structure instead of sharp corners. The contact has a rounded contour that follows the curvature of the isolation structure, preventing the contact from extending into sharp corner regions where short circuits would occur. This maintains manufacturing precision while eliminating the reliability issue.
2Area of moving object
If the contact extends to the sharp corner of the isolation structure, then the contact area is maximized, but the contact may connect with adjacent contacts causing short circuits
Solution Approach 1:
The contact structure applies local quality by having different geometries at different locations: the contact has a rounded corner configuration near the isolation structure to prevent short circuits, while maintaining adequate contact area in other regions. This localized geometric modification ensures both electrical isolation and sufficient contact area.
3Manufacturing precision
If the lining layer is formed conformally in the sharp corner, then the corner is fully covered, but the contact cannot be properly formed in that region
Solution Approach 1:
The lining layer is formed in advance in the sharp corner region of the isolation structure. This preliminary action of depositing the lining layer before contact formation creates a rounded corner profile that guides subsequent contact deposition, ensuring the contact naturally forms with a rounded contour without extending into the sharp corner, thus facilitating proper contact formation.
Data Source
AI summary
Some embodiments of the present disclosure provide a semiconductor structure including a dielectric layer stack, an isolation structure, a lining layer and a contact. The isolation structure is in contact with a sidewall of the dielectric layer stack, and the sidewall of the dielectric layer stack and a sidewall of the isolation structure define a sharp corner. The lining layer is at the sharp corner, and a sidewall of the lining layer, the sidewall of the dielectric layer stack and the sidewall of the isolation structure define a round corner. The contact is in contact with the sidewall of the dielectric layer stack, the sidewall of the isolation structure and the sidewall of the lining layer.