Dual Damascene Interconnects with Reinforcement Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Semiconductor devices face challenges in achieving improved structural integrity and electro-migration characteristics between conductive features, particularly in reducing capacitive coupling, dielectric breakdown, and void formation in interconnect layers, while maintaining low-k dielectric materials and avoiding costly material and tool additions.
Innovation Solution
The configuration of conductive features and dielectric layers includes a dual damascene structure with a high EM resistance material in the via portion, a reinforcement layer with voids to reduce dielectric constant, and a non-planar protective etch stop layer to enhance ion diffusion, all within a multilayered dielectric structure, without requiring additional expensive materials or fabrication tools.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If low-k dielectric materials are used to reduce capacitive coupling, then capacitance is reduced, but structural integrity and electro-migration resistance deteriorate
Solution Approach 1:
The patent uses a composite dielectric structure combining low-k material (for low capacitance) with a reinforcement layer containing voids (for mechanical strength). This composite approach allows the system to simultaneously achieve low capacitive coupling and improved structural integrity, resolving the contradiction between electrical performance and mechanical reliability
Solution Approach 2:
The reinforcement layer is configured with voids creating a porous structure that provides mechanical support to the low-k dielectric material. The voids reduce the effective dielectric constant while adding structural rigidity, thereby improving electro-migration resistance without sacrificing the low-capacitance benefit
2Object-affected harmful factors
If low-k dielectric materials are used to reduce capacitive coupling, then capacitance is reduced, but dielectric breakdown resistance deteriorates
Solution Approach 1:
The composite dielectric structure with reinforcement layer provides enhanced dielectric breakdown resistance while maintaining low capacitance. The reinforcement layer acts as a protective barrier that prevents premature breakdown of the low-k material
Solution Approach 2:
The reinforcement layer is positioned beforehand to protect the low-k dielectric material from breakdown stresses. This preventive structure cushions against electrical breakdown before it occurs in the low-k layer
3Ease of manufacture
If conventional interconnect structures are used, then manufacturing is simpler, but void formation occurs reducing reliability
Solution Approach 1:
The reinforcement layer is formed preliminarily before final interconnect structure completion. This preliminary structural support prevents void formation during subsequent processing steps while maintaining manufacturing simplicity through integration with existing process flows
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 configuration improves interconnect reliability, reduces voids and dielectric collapse, lowers capacitance, and enlarges critical dimensions without compromising the low-k dielectric's collapsing margin, thereby enhancing overall device performance and robustness.
Implementation Method 1
a reinforcement layer with voids to reduce dielectric constant
Implementation Method 2
a non-planar protective etch stop layer to enhance ion diffusion
Implementation Method 3
a dual damascene structure with a high EM resistance material in the via portion
Data Source
AI summary
An embodiment semiconductor device includes a first conductive feature in a dielectric layer and a second conductive feature over the dielectric layer and electrically connected to the first conductive feature. The second conductive feature includes a dual damascene structure and further includes a top portion within both a line portion and a via portion of the second conductive feature and a bottom portion in the via portion of the second conductive feature. The bottom portion comprises a different conductive material than the top portion, and a thickness of the bottom portion is at least about twenty percent of a total thickness of the via portion of the second conductive feature.