Tapered Barrier Contact Structure for Low-Resistance IC Interconnects
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Solution Overview
Problem
Existing IC devices face challenges in suppressing the increase in resistance of metal wiring layers and maintaining electrical characteristics and reliability as linewidth and pitch are miniaturized.
Innovation Solution
The integration of a conductive barrier pattern with a vertical barrier portion between the metal silicide film and the conductive plug, which has a tapered shape to minimize contact resistance and improve gap-fill characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of moving object
If the linewidth and pitch of metal wiring layers are miniaturized to improve device integration, then device density increases, but resistance of metal wiring layers increases and electrical characteristics deteriorate
Solution Approach 1:
The conductive barrier pattern is designed with a tapered width that varies locally along the vertical direction, being wider at the lower portion and narrower at the upper portion. This local variation in geometry optimizes both the contact resistance at the interface with the conductive plug and the overall electrical characteristics of the wiring structure, resolving the contradiction between miniaturization and electrical performance.
Solution Approach 2:
The invention changes the geometric parameters of the conductive barrier pattern, specifically the width in the lateral direction, which tapers along the vertical direction. This parameter change allows the structure to maintain low contact resistance while accommodating miniaturized linewidth and pitch, thereby improving electrical characteristics despite device downscaling.
2Ease of manufacture
If conventional metal wiring structures are used in miniaturized IC devices, then manufacturing simplicity is maintained, but resistance increases and reliability decreases
Solution Approach 1:
The conductive barrier pattern employs a tapered width profile that is wider at the lower portion and narrower at the upper portion. This local variation in geometry optimizes both the contact resistance at the interface with the conductive plug and the overall electrical characteristics of the wiring structure, resolving the contradiction between miniaturization and electrical performance.
3Ease of manufacture
If the conductive barrier pattern has a uniform width, then manufacturing is simpler, but contact resistance increases and voids may form
Solution Approach 1:
The conductive barrier pattern is designed with a tapered width that varies locally along the vertical direction, being wider at the lower portion and narrower at the upper portion. This local variation in geometry optimizes both the contact resistance at the interface with the conductive plug and the overall electrical characteristics of the wiring structure, resolving the contradiction between miniaturization and electrical performance.
Solution Approach 2:
The conductive barrier pattern features a tapered, curved width profile rather than a straight uniform width. This curved geometry improves the gap-fill characteristics during deposition, preventing void formation and ensuring continuous conductive pathways, thereby improving manufacturing precision without significantly complicating the fabrication process.
Data Source
AI summary
An integrated circuit (IC) device includes a conductive region including a first metal on a substrate. An insulating film is on the conductive region. A conductive plug including a second metal passes through the insulating film and extends in a vertical direction. A conductive barrier pattern is between the conductive region and the conductive plug. The conductive barrier pattern has a first surface in contact with the conductive region and a second surface in contact with the conductive plug. A bottom surface and a lower sidewall of the conductive plug are in contact with the conductive barrier pattern, and an upper sidewall of the conductive plug is in contact with the insulating film. The conductive barrier pattern includes a vertical barrier portion between the insulating film and the conductive plug, and the vertical barrier portion has a width tapering along a first direction away from the conductive region.