Tungsten Interconnect Structure Without a Diffusion Barrier
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Solution Overview
Problem
The challenge in semiconductor arrangements is the high electrical resistance and reduced reliability due to oxide formation at the interface of conductive features, which limits the conductivity and yield of semiconductor devices.
Innovation Solution
A process is employed to form an adhesion layer using the same material as the conductive layer, such as tungsten, which removes native oxides from the conductive feature's surface and sidewalls, eliminating the need for a diffusion barrier layer, thereby allowing a thicker conductive layer to be formed with improved conductivity and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a conventional adhesion layer with different material is used, then adhesion is improved, but electrical resistance increases due to oxide formation at the interface
Solution Approach 1:
The patent applies homogeneity by using the same material (tungsten) for both the adhesion layer and the conductive layer, eliminating material interfaces and oxide formation. This single-material approach ensures uniform electrical properties throughout the interconnect structure while maintaining adequate adhesion, thereby resolving the contradiction between adhesion strength and electrical conductivity.
2Stability of the object's composition
If a diffusion barrier layer is added, then material diffusion is prevented, but the conductive layer thickness is reduced and conductivity is worsened
Solution Approach 1:
The patent extracts and eliminates the diffusion barrier layer from the interconnect structure. By using tungsten throughout and controlling the fabrication process, the invention removes the unnecessary barrier layer that was previously required, thereby increasing the conductive layer thickness and improving electrical conductivity while still preventing material diffusion through process control.
3Reliability
If the conductive layer is made thicker to improve conductivity, then electrical resistance decreases, but process complexity increases due to oxide removal requirements
Solution Approach 1:
The patent applies self-service by using the tungsten deposition process itself to simultaneously form both the adhesion layer and the conductive layer in a unified process. This self-service approach eliminates the need for separate oxide removal steps and multiple material depositions, thereby reducing process complexity while enabling thicker conductive layers for improved conductivity.
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 approach enhances conductivity and reliability by removing oxides, allowing for a thicker conductive layer without a diffusion barrier, thus improving device performance and yield.
Implementation Method 1
The adhesion layer is formed by a process that also removes oxides from the upper surface of the underlying conductive feature, from the sidewalls defining the opening, and/or from the adhesion layer
Implementation Method 2
A conductive layer of the same material as the adhesion material is formed in the opening and over the adhesion layer
Data Source
AI summary
A semiconductor arrangement is provided. The semiconductor arrangement includes a dielectric layer defining an opening, an adhesion layer in the opening, and a conductive layer in the opening over the adhesion layer. A material of the conductive layer is a same material as an adhesion material of the adhesion layer.