Carbon-Containing Interconnect Barrier for Thin-Layer Diffusion Control
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Solution Overview
Problem
The fabrication of integrated chips faces challenges in forming effective interconnect structures, particularly with thinner diffusion barrier layers, as physical vapor deposition methods struggle to maintain reliability and yield at advanced scales, leading to issues with conductive material diffusion and adhesion in metal interconnect layers.
Innovation Solution
The implementation of a carbon-containing barrier layer formed using atomic layer deposition (ALD) or chemical vapor deposition (CVD) techniques, which includes carbon impurities to enhance adhesion and prevent conductive material diffusion, is applied along the sidewalls and bottom surfaces of conductive features within the interconnect structure, ensuring uniform deposition and maintaining a specific carbon concentration for optimal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If physical vapor deposition (PVD) is used to deposit thinner barrier layers, then the barrier layer thickness is reduced, but the reliability and yield deteriorate due to conductive material diffusion and adhesion issues
Solution Approach 1:
The patent changes the compositional parameters of the barrier layer by incorporating carbon-containing materials (such as carbon-doped silicon oxide, carbon-doped silicon nitride, or amorphous carbon) into the barrier layer structure. This compositional modification enables the barrier layer to maintain effective thickness at advanced nodes while preventing copper diffusion and ensuring proper adhesion, thereby resolving the contradiction between thinness and reliability.
Solution Approach 2:
The patent employs composite barrier layer structures that combine multiple materials with carbon-containing compounds (e.g., silicon oxide with carbon, silicon nitride with carbon, or tungsten silicide with carbon). These composite structures leverage the complementary properties of each material to achieve both the required barrier functionality and adhesion performance at reduced thicknesses, addressing the reliability issue while maintaining thin dimensions.
2Ease of manufacture
If physical vapor deposition (PVD) is used for barrier layer deposition, then the deposition process is simpler, but the manufacturing precision deteriorates due to poor adhesion and diffusion control
Solution Approach 1:
The patent modifies the material composition parameters by introducing carbon-containing compounds into the barrier layer, which fundamentally changes the deposition characteristics and adhesion properties. This compositional change enables precise control over barrier layer formation, copper diffusion prevention, and adhesion enhancement, thereby achieving high manufacturing precision while maintaining process feasibility.
Solution Approach 2:
The carbon-containing barrier layer acts as an intermediary between the copper conductive material and the underlying dielectric or metal layers. This intermediary layer provides graded composition and intermediate bonding characteristics that facilitate controlled deposition, prevent direct copper-dielectric interaction, and ensure proper adhesion, thereby improving manufacturing precision without significantly complicating the overall process.
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 improves the reliability and yield of interconnect structures by preventing conductive material diffusion and enhancing adhesion, thereby maintaining device performance characteristics and reducing issues associated with low yield and reliability.
Implementation Method 1
a carbon-containing barrier layer configured to prevent diffusion of the conductive material into the dielectric layer
Implementation Method 2
enhance adhesion and prevent conductive material diffusion
Data Source
AI summary
An interconnect structure and a method of forming an interconnect structure are disclosed. The interconnect structure includes a conductive plug over a substrate; a conductive feature over the conductive plug, wherein the conductive feature has a first sidewall, a second sidewall facing the first sidewall, and a bottom surface; and a carbon-containing barrier layer having a first portion along the first sidewall of the conductive feature, a second portion along the second sidewall of the conductive feature, and a third portion along the bottom surface of the conductive feature.