Silicide and Silicon Nitride Interlayers for Low-Loss Copper Adhesion
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Solution Overview
Problem
Current package assemblies face challenges in achieving high signal frequency and density due to signal loss and delamination issues at high frequencies, particularly with roughened copper traces leading to reduced copper dimensions and increased insertion losses.
Innovation Solution
The implementation of a silicide layer and a silicon nitride layer between the copper traces and the dielectric, allowing for a strong chemical bond without roughening the copper surfaces, thereby enhancing adhesion and reducing signal loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If roughened copper traces are used to enhance adhesion, then adhesion strength is improved, but signal loss and insertion loss increase at high frequencies
Solution Approach 1:
A silicide layer is introduced as an intermediary between the copper trace and the dielectric. This silicide layer forms a chemical bond with both the copper and the dielectric, providing adhesion without requiring copper surface roughening, thereby maintaining smooth copper surfaces for reduced signal loss.
Solution Approach 2:
The invention extracts the adhesion function from the copper surface itself (by removing the need for roughening) and transfers it to a separate silicide layer. This allows the copper surface to remain smooth for electrical performance while the silicide layer provides the mechanical adhesion function.
2Strength
If roughened copper surfaces are used, then adhesion is improved, but copper dimensions are reduced
Solution Approach 1:
The silicide layer acts as a mediator that provides the adhesion interface, eliminating the need to remove copper material through roughening processes. The copper trace maintains its full plated dimensions while the silicide layer provides the necessary bonding surface area.
Solution Approach 2:
The adhesion function is segmented from the copper trace structure and placed in a separate silicide layer. This segmentation allows the copper dimensions to be maximized while the silicide layer provides the adhesion interface independently.
3Strength
If copper surfaces are roughened to increase surface area for bonding, then adhesion is improved, but insertion loss increases
Solution Approach 1:
The silicide layer serves as an intermediary bonding layer that provides the increased surface area and chemical bonding sites needed for strong adhesion, while the copper surfaces remain smooth to minimize insertion loss. The silicide layer effectively decouples the adhesion requirement from the electrical performance requirement.
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 enables higher signal frequencies, reduced insertion loss, and increased substrate life by maintaining unroughened copper surfaces, facilitating higher I/O density and improved electrical performance.
Implementation Method 1
a silicide layer, which may be referred to as a silicide interlayer, and a silicon nitride layer may be placed between a copper trace and a dielectric on the copper trace to reduce the delamination risk of the dielectric from the copper trace
Implementation Method 2
In embodiments, the silicide interlayer and the silicon nitride layer may be applied using a single-tool during the manufacturing process, for example a chemical vapor deposition (CVD) process that involves a physical vapor deposition (PVD) process that involves plasma assisted deposition
Data Source
AI summary
Embodiments herein relate to systems, apparatuses, or processes for forming a silicide and a silicon nitrate layer between a copper feature and dielectric to reduce delamination of the dielectric. Embodiments allow an unroughened surface for the copper feature to reduce the insertion loss for transmission lines that go through the unroughened surface of the copper. Embodiments may include sequential interlayers between a dielectric and copper. Other embodiments may be described and/or claimed.