Composite Titanium Nitride Barrier Layer for Semiconductor Adhesion
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Solution Overview
Problem
In semiconductor device manufacturing, existing methods for forming barrier layers using tungsten interconnections face challenges in achieving optimal adhesion and resistance, particularly in loose areas where conventional single-layer barrier layers result in defects due to poor adhesion and higher stress during chemical mechanical polishing.
Innovation Solution
A method involving the formation of a composite barrier layer with a first and second titanium nitride layer, each subjected to specific plasma treatments to achieve distinct N/Ti ratios, providing improved adhesion and resistance by adjusting the nitrogen concentration gradient, thereby supporting the formation of efficient interconnections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer barrier layer is used, then the manufacturing process is simple, but adhesion is poor and stress is high during chemical mechanical polishing
Solution Approach 1:
The barrier layer is divided into multiple sub-layers with different materials and nitrogen concentrations. The patent forms a composite barrier layer comprising a first barrier layer and a second barrier layer, where each layer has distinct properties. This segmentation allows each sub-layer to perform specific functions, improving overall adhesion while managing stress during CMP processes.
Solution Approach 2:
Different regions of the barrier layer are given different local properties through varying nitrogen concentrations and material compositions. The patent applies plasma treatment to specific layers to achieve different N/Ti ratios, creating local quality variations that optimize adhesion in critical areas while maintaining overall structural integrity and reducing CMP stress.
2Ease of manufacture
If a single-layer barrier layer is used, then the manufacturing process is simple, but stress during chemical mechanical polishing is high
Solution Approach 1:
The barrier layer is divided into multiple sub-layers with different materials and nitrogen concentrations. The patent forms a composite barrier layer comprising a first barrier layer and a second barrier layer, where each layer has distinct properties. This segmentation allows each sub-layer to perform specific functions, improving overall adhesion while managing stress during CMP processes.
Solution Approach 2:
The patent changes physical and chemical parameters of the barrier layer by applying plasma treatment to achieve different N/Ti ratios in different layers. This parameter variation creates a gradient structure that effectively manages stress distribution during chemical mechanical polishing, reducing defects while maintaining manufacturing feasibility.
3Reliability
If plasma treatment is applied to achieve different N/Ti ratios, then adhesion is improved, but the manufacturing process becomes more complex
Solution Approach 1:
Plasma treatment is applied in advance to specific barrier layer sub-layers during the formation process to achieve the desired N/Ti ratios before subsequent deposition steps. This preliminary action ensures optimal adhesion properties are established early in the manufacturing process, preventing defects before they propagate through later fabrication steps.
Solution Approach 2:
The patent changes physical and chemical parameters of the barrier layer by applying plasma treatment to achieve different N/Ti ratios in different layers. This parameter variation creates a gradient structure that effectively manages stress distribution during chemical mechanical polishing, reducing defects while maintaining manufacturing feasibility.
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
The composite barrier layer enhances adhesion and maintains low resistance by optimizing nitrogen concentration, reducing defects and stress during interconnection formation, particularly in loose areas, compared to conventional single-layer approaches.
Implementation Method 1
A first plasma treatment is applied to the first titanium nitride layer such that the first titanium nitride layer has a first N/Ti ratio. A second plasma treatment is applied to the second titanium nitride layer such that the second titanium nitride layer has a second N/Ti ratio larger than the first N/Ti ratio.
Data Source
AI summary
A method for manufacturing a semiconductor structure includes the following steps. At first, a titanium layer is formed on a preformed layer. Then, a first titanium nitride layer is formed on the titanium layer. A first plasma treatment is applied to the first titanium nitride layer such that the first titanium nitride layer has a first N/Ti ratio. A second titanium nitride layer is formed on the first titanium nitride layer. A second plasma treatment is applied to the second titanium nitride layer such that the second titanium nitride layer has a second N/Ti ratio larger than the first N/Ti ratio.