ELK Inter-Metal Dielectric Stack for Low Capacitance Reliability
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Solution Overview
Problem
Advanced semiconductor technologies, such as the 5-nanometer node and beyond, face challenges in achieving desired capacitance, yield, and reliability due to the susceptibility of low-k dielectric materials to damage during processing, which affects signal transport speed and device performance.
Innovation Solution
A method for manufacturing an extra low-k (ELK) dielectric layer involving a stacked structure of dielectric material layers, including an aluminum nitride layer, oxygen-doped carbide layers, and an aluminum oxide layer, with a carbon-doped oxygen-rich silicon oxide ELK layer formed using PECVD or PVD processes, and a nitrogen-free antireflection layer for protection, to enhance adhesion and reduce capacitance while improving hardness and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If low-k dielectric material is used to form IMD layers, then capacitance contribution is reduced and signal transport speed is improved, but the material becomes susceptible to damage during etching, deposition, and wet processes
Solution Approach 1:
The patent applies composite materials by combining low-k dielectric material with a protective coating layer. The low-k material (such as silicon oxide, silicon oxynitride, or fluorinated materials) provides the desired low capacitance properties, while the protective coating (such as silicon nitride, silicon carbide, or diamond-like carbon) forms a composite structure that shields the low-k material from damage during etching, deposition, and wet processes, thereby resolving the contradiction between signal speed improvement and processing reliability
Solution Approach 2:
The patent implements beforehand cushioning by applying a protective coating layer to the low-k dielectric material before subsequent processing steps. This protective layer acts as a cushion or shield that prevents direct exposure of the fragile low-k material to harsh processing conditions, thereby protecting it from damage while maintaining its low capacitance functionality
2Object-generated harmful factors
If low-k dielectric material is used, then capacitance contribution is reduced, but the high porosity makes it susceptible to damage and degrades dielectric constant
Solution Approach 1:
The patent uses composite materials where the low-k dielectric layer is combined with a protective coating layer. The low-k material maintains its low capacitance properties while the protective coating (such as silicon nitride or diamond-like carbon) provides structural stability and protects against porosity-related degradation, thus maintaining dielectric constant stability
Solution Approach 2:
The patent applies parameter changes by modifying the physical and chemical properties of the dielectric structure through the protective coating. The coating alters the surface properties and structural integrity parameters, preventing porosity from increasing and dielectric constant from degrading, while allowing the bulk low-k material to maintain its low capacitance characteristics
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 ELK dielectric layer improves signal transport speed by reducing coupling capacitance and enhancing reliability, making it more resistant to damage compared to traditional low-k materials, thus addressing the limitations of low-k dielectric materials in advanced semiconductor processing.
Implementation Method 1
a carbon-doped oxygen-rich silicon oxide ELK layer formed using PECVD or PVD processes
Implementation Method 2
a carbon-doped oxygen-rich silicon oxide ELK layer formed using PECVD or PVD processes
Data Source
AI summary
A method for manufacturing an extra low-k (ELK) inter-metal dielectric (IMD) layer includes forming a first IMD layer including a plurality of dielectric material layers over a substrate. An adhesion layer is formed over the first IMD layer. An ELK dielectric layer is formed over the adhesion layer. A protection layer is formed over the ELK dielectric layer. A hard mask is formed over the protection layer and is patterned to create a window. Layers underneath the window are removed to create an opening. The removed layers include the protection layer, the ELK dielectric layer, the adhesion layer, and the first IMD layer. A metal layer is formed in the opening.