Fin-Shaped Metal Gate Electrode for Self-Aligned Contact Reliability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As gate pitch shrinks in advanced technology nodes, the use of self-aligned contacts increases the risk of unwanted electrical issues due to the complexity of etching final structures.
Innovation Solution
The implementation of a fin gate electrode with a increased surface area to reduce gate resistance, combined with controlled gapfill area over the fin gate electrode using a low-k dielectric layer, to prevent electrical issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If self-aligned contacts are used to reduce gate pitch, then device integration density is improved, but the risk of unwanted electrical issues increases due to etching complexity
Solution Approach 1:
The gate electrode is segmented into a fin-shaped structure with multiple vertical surfaces instead of a single planar contact area. This segmentation increases the effective contact surface area with the underlying semiconductor fin, improving electrical connection reliability while maintaining the self-aligned contact geometry needed for high integration density
Solution Approach 2:
The gate electrode contact structure transitions from a two-dimensional planar contact to a three-dimensional fin-shaped structure that extends vertically. This dimensional change increases the contact surface area without increasing the lateral footprint, allowing self-aligned contacts to maintain both high integration density and improved electrical reliability
2Reliability
If gate electrode surface area is increased to reduce gate resistance, then electrical performance is improved, but gapfill control becomes more difficult
Solution Approach 1:
The gate electrode structure implements local quality variations through its fin-shaped geometry, concentrating the increased surface area at the vertical interfaces with the semiconductor fin while maintaining controlled gapfill regions in the horizontal planes. This allows improved electrical performance locally without compromising overall manufacturing precision
Solution Approach 2:
The invention changes the geometric parameters of the gate electrode from a planar shape to a fin-shaped three-dimensional structure. This parameter change increases the surface area for electrical contact while the vertical orientation and controlled dimensions maintain manufacturability and gapfill control during fabrication
Data Source
AI summary
Embodiments provide a replacement metal gate in a FinFET or nanoFET which utilizes a conductive metal fill. The conductive metal fill has an upper surface which has a fin shape which may be used for a self-aligned contact.