Segmented Via Conductor Structure for High-Aspect-Ratio Reliability
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Solution Overview
Problem
The miniaturization of semiconductor devices leads to increased aspect ratios in interconnects and via plugs, which can result in reliability issues such as void generation and diffusion of components, compromising the integrity of the semiconductor device.
Innovation Solution
A semiconductor device configuration with specific conductor and barrier film structures, including a first conductor thinner than the insulating film, surrounded by multiple barrier films, is used to moderate the aspect ratio and prevent component diffusion, using methods like ALD and electrolytic plating to form these structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If miniaturization of interconnect and via plug is promoted, then device density and integration are improved, but aspect ratio increases leading to reliability degradation
Solution Approach 1:
The via plug is divided into multiple segments: a lower conductor layer grown from the lower layer interconnect, an insulating film layer, and an upper conductor layer. This segmentation allows each layer to be optimized independently, reducing the effective aspect ratio that each conductor layer must bridge while maintaining overall via functionality.
Solution Approach 2:
An insulating film is introduced as an intermediary layer between the lower and upper conductor layers. This insulating film acts as a mediator that prevents direct contact and potential diffusion between conductors while providing structural support that reduces the aspect ratio of the overall via structure.
2Reliability
If aspect ratio of via plug is reduced, then reliability is improved, but device density and integration are degraded
Solution Approach 1:
The via structure transitions from a simple vertical plug to a multi-layered structure with horizontal differentiation. By adding conductor and insulating layers in the horizontal dimension, the effective vertical aspect ratio is reduced without increasing the overall via footprint, thus maintaining device density.
3Manufacturing precision
If conductor is grown from lower layer interconnect, then aspect ratio is reduced, but void generation and component diffusion occur
Solution Approach 1:
The insulating film serves as an intermediary barrier between the lower conductor layer and the upper conductor layer, preventing component diffusion while maintaining the beneficial low aspect ratio achieved through selective conductor growth from the lower layer interconnect.
Solution Approach 2:
Different regions of the via structure are assigned different materials and properties: the lower conductor layer provides electrical connectivity, the insulating film provides diffusion barrier and structural support, and the upper conductor layer completes the electrical path. This local optimization prevents void generation and component diffusion.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration enhances the reliability of semiconductor devices by preventing void formation and component diffusion, thereby improving the integrity and performance of interconnects with high aspect ratios.
Implementation Method 1
a conductor is selectively grown from a lower layer interconnect by atomic layer deposition (ALD) or the like
Implementation Method 2
a film covering a side surface of the second portion and containing a metal or containing silicon and nitrogen... the film covering the side surface of the second portion and containing silicon and nitrogen may prevent diffusion of a component of the lower layer interconnect into the third insulating film
Data Source
AI summary
A semiconductor device includes: a first insulating film; an interconnect disposed in the first insulating film and containing copper, cobalt, nickel, or manganese; a second insulating film that includes a first portion connected to the interconnect and that contains silicon and nitrogen; a third insulating film including a second portion connected to the first portion; a first conductor disposed in the first portion and in contact with the interconnect; a film covering a side surface of the second portion and containing a metal or containing silicon and nitrogen; and a second conductor disposed in the second portion and in contact with the film.