Semiconductor Contact Opening Fill Without Conductive Barrier Layers
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Solution Overview
Problem
The semiconductor industry faces challenges in scaling down device geometry and increasing functional density, which leads to issues such as the need for conductive barrier layers that can impede conductivity and increase manufacturing costs.
Innovation Solution
The formation of conductive features without a conductive barrier layer by treating the dielectric layer to enhance selectivity and prevent grain boundary formation, allowing for improved conductivity and reduced thermal budget, enabling higher aspect ratio features and efficient deposition in narrower openings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conductive barrier layer is used to impede conductivity, then conductivity control is improved, but manufacturing cost increases
Solution Approach 1:
The patent removes the conductive barrier layer from the conventional structure, extracting the problematic element that caused both the conductivity control issue and the manufacturing cost increase. The copper plug is deposited directly into the contact hole without a barrier layer, eliminating the source of grain boundaries while maintaining proper conductivity control through the deposition process itself.
Solution Approach 2:
Instead of using a barrier layer to control conductivity (traditional approach), the patent inverts the approach by using direct copper deposition without a barrier layer. The conductivity control is achieved through the deposition process parameters and the inherent properties of copper, rather than through an intermediate barrier layer.
2Reliability
If a conductive barrier layer is deposited, then conductivity control is improved, but device complexity increases
Solution Approach 1:
The patent extracts and removes the conductive barrier layer from the device structure, simplifying the overall structure. This eliminates the need for additional deposition steps and reduces the number of layers that need to be managed during fabrication and assembly.
Solution Approach 2:
The patent merges the functions that were previously separated into distinct layers (barrier layer and copper plug) into a single direct copper deposition process. This consolidation reduces structural complexity while maintaining the essential conductivity control function.
3Manufacturing precision
If conductive material is deposited in narrow openings, then aspect ratio is improved, but deposition selectivity becomes more challenging
Solution Approach 1:
The patent changes the deposition parameters to achieve high selectivity in narrow openings. By optimizing deposition conditions (such as using atomic layer deposition with controlled precursor flow and temperature), the process achieves superior conformal coverage and fill control in high aspect ratio contact holes without requiring a barrier layer.
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 the conductivity of integrated circuits, reduces manufacturing costs, and improves process efficiency by eliminating the need for barrier layers, leading to better performance and yield in semiconductor devices.
Implementation Method 1
the dielectric layer may be treated to increase the selectivity of the conductive material of the conductive feature to be deposited in the opening versus deposited onto the dielectric layer
Implementation Method 2
depositing a conductive material in the contact opening
Data Source
AI summary
A method of forming a semiconductor device includes: forming a semiconductor feature over a substrate, the semiconductor feature includes a conductive region; forming a dielectric layer over the semiconductor feature; patterning the dielectric layer to form a contact opening exposing a top surface of the conductive region; forming a monolayer over the dielectric layer, the top surface of the conductive region remaining exposed; and depositing a conductive material in the contact opening.