Interconnect Structure With Oxide Glue Layer for ULK Adhesion
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Solution Overview
Problem
Traditional interconnect structures in semiconductor manufacturing face issues with resistive-capacitive (RC) delay performance due to poor adhesion at the interface between ultra low-k (ULK) dielectric layers and barrier layers, leading to film delamination during packaging and chemical-mechanical polish processes.
Innovation Solution
Incorporating an oxide glue layer between the barrier layer and the ultra low-k dielectric layer, formed using tetraethyl orthosilicate (TEOS) as a precursor, to enhance interface adhesion and maintain porosity below 40%, thereby preventing delamination and improving mechanical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an ultra low-k dielectric layer with high porosity is used to improve RC delay performance, then the dielectric constant is reduced and RC delay performance is improved, but the interface adhesion deteriorates causing film delamination during packaging
Solution Approach 1:
An oxide glue layer is introduced as an intermediary between the barrier layer and the ultra low-k dielectric layer. This intermediate layer serves as a transition zone that provides strong adhesion to both the barrier layer and the ULK layer, preventing delamination while allowing the ULK layer to maintain its high porosity and low dielectric constant for improved RC delay performance.
Solution Approach 2:
The interconnect structure employs a composite material approach by combining the barrier layer, oxide glue layer, and ultra low-k dielectric layer into a multi-layer composite structure. Each layer contributes specific properties: the barrier layer provides electrical isolation, the oxide glue layer provides adhesion, and the ULK layer provides low dielectric constant. This composite structure resolves the contradiction by distributing functions across different materials.
2Strength
If the porosity of the ultra low-k dielectric layer is reduced to improve adhesion, then interface adhesion is improved, but RC delay performance deteriorates
Solution Approach 1:
The oxide glue layer acts as a mediator that decouples the relationship between porosity and adhesion. It allows the ultra low-k dielectric layer to maintain high porosity (better than 60% in some embodiments) for optimal RC delay performance, while the oxide glue layer itself provides the necessary adhesion strength to prevent delamination during packaging and processing.
3Ease of manufacture
If a traditional low-k barrier structure is used, then manufacturing is simpler, but RC delay performance is insufficient for next generation products
Solution Approach 1:
The traditional single-layer low-k structure is segmented into multiple functional layers: a barrier layer for electrical isolation, an oxide glue layer for adhesion, and an ultra low-k dielectric layer for low RC delay. This segmentation allows each layer to be optimized for its specific function, achieving next-generation RC delay performance while maintaining manufacturability through established deposition and processing techniques.
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 oxide glue layer ensures adhesion between the barrier and ultra low-k dielectric layers, preventing delamination and crack formation during processing, while the ultra low-k dielectric layer's low dielectric constant enhances RC delay performance and mechanical stability, improving product yield and reliability.
Implementation Method 1
the oxide glue layer can provide interface adhesion to the underlying barrier layer and the overlying ultra low-k dielectric layer
Implementation Method 2
the ultra low-k dielectric layer has porosity less than 40% and a dielectric constant less than 2.5
Implementation Method 3
the ultra low-k dielectric layer has porosity less than 40%
Data Source
AI summary
An interconnect structure includes a barrier layer, an oxide glue layer, and an ultra low-k dielectric layer. The oxide glue layer is located on the barrier layer. The ultra low-k dielectric layer is located on the oxide glue layer, wherein the oxide glue layer is located between the barrier layer and the ultra low-k dielectric layer, and the ultra low-k dielectric layer has porosity less than 40%.