FinFET Contact Separation Structure for Isolation and Contact Area
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Solution Overview
Problem
The increasing demand for high-performance, high-speed, and multifunctional semiconductor devices requires finer patterns and three-dimensional channel structures, such as FinFETs, to overcome the limitations of planar metal oxide semiconductor devices, but existing manufacturing methods face challenges in achieving improved productivity and electrical characteristics.
Innovation Solution
The semiconductor device design includes active regions with parallel fin structures, gate structures intersecting these regions, source/drain regions, a vertical conductive structure, and contact plugs with a contact separation pattern that contacts the vertical conductive structure, enhancing electrical connectivity and isolation between components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If contact separation pattern is added to separate contact plugs, then electrical isolation between contact plugs is improved, but device complexity increases
Solution Approach 1:
The contact separation pattern is merged with the gate separation pattern, forming a unified structure that serves dual purposes: separating contact plugs electrically while maintaining the gate structure's separation function. This integration reduces the number of separate components needed, thereby reducing overall device complexity while achieving the desired electrical isolation.
Solution Approach 2:
The contact separation pattern is designed to perform multiple functions simultaneously: it separates the first and second contact plugs electrically, maintains alignment with the gate structures, and integrates with the existing gate separation pattern. This multi-functionality reduces the need for additional separate structures, addressing the complexity issue while ensuring reliable electrical isolation.
2Reliability
If vertical conductive structure is added in gate separation pattern, then electrical connectivity is improved, but manufacturing precision requirements increase
Solution Approach 1:
The vertical conductive structure is formed within the gate separation pattern before the contact plugs are formed. This preliminary action establishes the conductive pathway in advance, allowing subsequent contact plug formation to align with pre-established reference structures (the vertical conductive structure and gate patterns), thereby reducing the precision requirements for final alignment.
Solution Approach 2:
The vertical conductive structure acts as an intermediary element that mediates between the lower interconnection lines and the contact plugs. By providing a pre-formed conductive pathway with known position and dimensions, it serves as a reference for aligning contact plugs, reducing the direct precision requirements for contact plug-to-source/drain alignment.
3Reliability
If contact separation pattern with narrower upper portion is used, then contact area is improved, but manufacturing complexity increases
Solution Approach 1:
The contact separation pattern is segmented into distinct regions: a lower portion that is wider for structural stability and ease of formation, and an upper portion that is narrower to provide adequate contact area with source/drain regions. This segmentation allows each portion to be optimized for its specific function while being formed through a single etching process, maintaining manufacturing simplicity.
Solution Approach 2:
Different portions of the contact separation pattern are given different widths according to local requirements: the lower portion has greater width for structural support and ease of manufacturing, while the upper portion has reduced width to maximize contact area with the source/drain regions. This local differentiation is achieved through selective etching that preserves the desired geometry without requiring complex multi-step processes.
Data Source
AI summary
A semiconductor device includes parallel active regions on a substrate and extending in a first horizontal direction; gate structures intersecting the active regions, extending in a second horizontal direction, and including first and second gate structures opposing each other in the second horizontal direction; source/drain regions including first and second source/drain regions, on at least one side of the gate structures and on the active regions; a gate separation pattern between the first and second gate structures; a vertical conductive structure in the gate separation pattern; contact plugs including a first contact plug electrically connected to the first source/drain region and the vertical conductive structure, and a second contact plug electrically connected to the second source/drain region and spaced apart from the vertical conductive structure; and a contact separation pattern separating the first and second contact plugs, having a portion contacting an upper surface of the vertical conductive structure.