Copper Via Barrier with Damage Curing and Mn Cap
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Solution Overview
Problem
Copper diffusion in semiconductor devices with low-k insulating interlayers is challenging to prevent while maintaining the low dielectric constant characteristics, leading to electrical performance issues.
Innovation Solution
A semiconductor device structure incorporating a low-k insulating interlayer with a damage curing layer and a copper-manganese capping pattern, where the damage curing layer has higher Si-C bond density and lower porosity than the insulating interlayer, and the copper-manganese capping pattern is formed on the copper structure to prevent copper diffusion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a barrier layer is formed to prevent copper diffusion, then copper diffusion is reduced, but the low-k characteristics of the insulating interlayer deteriorate
Solution Approach 1:
The barrier structure is segmented into multiple functional layers: a damage curing layer (first barrier layer) formed on the insulating interlayer with higher Si-C bond density and lower porosity, and a copper-manganese capping pattern (second barrier layer) formed on the copper structure. This segmentation allows each layer to perform its specific function - the damage curing layer preserves low-k characteristics while the capping pattern provides enhanced copper diffusion prevention.
Solution Approach 2:
Different regions of the barrier structure have different properties optimized for their specific functions. The damage curing layer has higher Si-C bond density and lower porosity compared to the insulating interlayer to provide localized protection. The copper-manganese capping pattern has higher manganese concentration at the top surface to enhance barrier properties where copper diffusion is most problematic, while maintaining overall low-k characteristics of the insulating interlayer.
2Reliability
If the porosity of the insulating interlayer is reduced to prevent copper diffusion, then copper diffusion is reduced, but the dielectric constant increases
Solution Approach 1:
The damage curing layer is formed with locally modified properties - higher Si-C bond density and lower porosity - only in the regions where copper diffusion prevention is critical (on the inner surface of the recess). The bulk insulating interlayer maintains its original low porosity and low dielectric constant characteristics, thus preventing copper diffusion locally without compromising the overall low-k performance of the insulating interlayer.
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 solution effectively reduces copper diffusion and improves electrical characteristics by maintaining the low dielectric constant of the insulating interlayer while enhancing the barrier properties against copper migration.
Implementation Method 1
The damage curing layer may have porosity lower than the porosity of the insulating interlayer. The damage curing layer may include an insulating material having Si—C bonds, and a density of the Si—C bonds in the damage curing layer may be higher than a density of Si—C bonds in the insulating interlayer.
Implementation Method 2
The copper structure may include a copper pattern and a copper-manganese capping pattern covering a surface of the copper pattern.
Data Source
AI summary
A semiconductor device includes an insulating interlayer on a first region of a substrate. The insulating interlayer has a recess therein and includes a low-k material having porosity. A damage curing layer is formed on an inner surface of the recess. A barrier pattern is formed on the damage curing layer. A copper structure fills the recess and is disposed on the barrier pattern. The copper structure includes a copper pattern and a copper-manganese capping pattern covering a surface of the copper pattern. A diffusion of metal in a wiring structure of the semiconductor device may be prevented, and thus a resistance of the wiring structure may decrease.