Nitrided Dielectric Surface Copper Interconnect Barrier
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Solution Overview
Problem
Conventional semiconductor devices face challenges with copper interconnection lines diffusing through silicon dioxide, requiring additional deposition chambers for tantalum nitride barrier layers, increasing production costs and complexity.
Innovation Solution
A method involving nitridation of dielectric surfaces to form a nitrided interconnect dielectric material surface, followed by depositing tantalum and copper, which eliminates the need for separate chambers by using the same chamber for pre-clean and nitridation processes, and achieves effective diffusion barrier performance with lower resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If tantalum nitride (TaN) is used as a conductive barrier layer to prevent copper diffusion, then diffusion barrier performance is improved, but device complexity and manufacturing cost increase due to requiring additional deposition chambers
Solution Approach 1:
The patent combines the pre-clean process and nitridation process into a single deposition chamber operation. The chamber performs both functions sequentially: first cleaning the dielectric surface, then nitridating it to form the diffusion barrier. This eliminates the need for separate chambers for each process, reducing device complexity while maintaining the required diffusion barrier performance.
Solution Approach 2:
The deposition chamber is designed to perform multiple functions: pre-cleaning dielectric surfaces and nitridating them to create diffusion barriers. This multi-functional approach allows a single chamber to replace what would traditionally require multiple specialized chambers, reducing overall system complexity while achieving the same reliability outcomes.
2Reliability
If tantalum nitride (TaN) is used as a conductive barrier layer, then diffusion barrier performance is improved, but manufacturing cost increases due to additional deposition chambers
Solution Approach 1:
The patent merges the pre-clean and nitridation processes into a single deposition chamber operation. By combining these two steps that would traditionally require separate chambers, the manufacturing infrastructure is reduced, leading to lower capital equipment costs and reduced manufacturing complexity while maintaining effective diffusion barrier performance.
3Manufacturing precision
If conventional pre-clean and nitridation processes are used separately, then process control is improved, but productivity decreases due to multiple process steps
Solution Approach 1:
The patent combines pre-clean and nitridation into a single integrated process sequence within one deposition chamber. This reduces the total number of process steps and eliminates intermediate handling, improving productivity while maintaining precise control over both functions through the chamber's controlled environment and sequential operation.
Solution Approach 2:
The pre-clean function is performed as a preliminary step within the same chamber before nitridation. This preliminary action prepares the surface for optimal nitridation without requiring a separate process step, streamlining the overall workflow while ensuring proper surface preparation for the diffusion barrier formation.
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 reliability and efficiency of semiconductor interconnect structures by reducing manufacturing complexity and costs while providing a suitable diffusion barrier for copper interconnection lines.
Implementation Method 1
performing a nitridation process that converts surfaces of the opening of the first dielectric material into nitrided residues, and forms a nitrided interconnect dielectric material surface in the opening
Implementation Method 2
depositing tantalum to create a tantalum layer on the nitrided interconnect dielectric surface region. The method includes depositing copper to fill the opening
Data Source
AI summary
Aspects of the present disclosure include a method of forming a semiconductor interconnect structure and the interconnect structure. The method includes etching an opening in a first interconnect dielectric material. The method includes performing a nitridation process that converts the surfaces of the opening into nitride residues, and forms a nitrided interconnect dielectric material surface in the opening. The method includes depositing tantalum to create a tantalum layer on the nitrided interconnect dielectric surface region. The method includes depositing copper to fill the opening and planarizing the surface of the first dielectric material.