Semiconductor Contact Structure With Densified Nitride Via Isolation
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Solution Overview
Problem
The scaling down of semiconductor devices has led to smaller electrical isolation regions between contact structures, resulting in inadequate dielectric layers that fail to prevent conductive material leakage between adjacent via structures, degrading the performance and reliability of MOSFETs, finFETs, and GAA FETs.
Innovation Solution
The implementation of barrier layers with higher material density, etch resistance, and resistance to halogen and oxygen diffusion, specifically a stack of nitride layers, is introduced between adjacent via structures to prevent conductive material leakage. These barrier layers surround the conductive plugs and via structures, and post-deposition treatments such as plasma, UV radiation, and thermal treatments are applied to enhance their structural integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device dimensions are scaled down to increase storage capacity and processing speed, then productivity and performance are improved, but electrical isolation between contact structures deteriorates leading to conductive material leakage
Solution Approach 1:
A dielectric layer is introduced as an intermediary substance between adjacent contact structures (via structures) to prevent conductive material leakage. This intermediate layer acts as a barrier that electrically isolates the contact structures while allowing the devices to maintain scaled-down dimensions for high productivity.
Solution Approach 2:
The dielectric layer is formed as a thin, sacrificial-like structure that can be selectively removed or modified during fabrication. While not exactly disposable, the dielectric material serves a temporary isolation function during manufacturing and can be etched away or penetrated as needed, enabling the scaling process to proceed effectively.
2Quantity of substance
If dielectric layer thickness is reduced to enable further scaling, then device density is improved, but material loss and oxidation increase degrading device integrity
Solution Approach 1:
The dielectric layer undergoes parameter changes through thermal treatment and plasma exposure that increase its density and reduce its porosity. These parameter changes transform the dielectric material from a more porous state to a denser state, reducing material loss and oxidation while maintaining the thin profile needed for high device density.
Solution Approach 2:
The dielectric layer exhibits different local qualities: it remains thin and low-k in regions where electrical isolation is needed, but undergoes localized densification through thermal and plasma treatment in regions where mechanical strength and oxidation resistance are critical. This spatial variation in material properties optimizes both device density and material stability.
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 barrier layers effectively minimize current leakage between adjacent via structures, enhancing the reliability and performance of semiconductor devices by preventing material loss and oxidation, thus maintaining electrical isolation and device integrity.
Implementation Method 1
performing a densification process on the semiconductor nitride layer to form a densified semiconductor nitride layer
Implementation Method 2
post-deposition treatments such as plasma, UV radiation, and thermal treatments are applied to enhance their structural integrity
Implementation Method 3
post-deposition treatments such as plasma, UV radiation, and thermal treatments are applied to enhance their structural integrity
Implementation Method 4
post-deposition treatments such as plasma, UV radiation, and thermal treatments are applied to enhance their structural integrity
Implementation Method 5
barrier layers with higher material density, etch resistance, and resistance to halogen and oxygen diffusion
Data Source
AI summary
A semiconductor device and a method of fabricating the semiconductor device are disclosed. The method includes forming a fin base on a substrate, epitaxially growing a S/D region on the fin base, forming a contact opening on the S/D region, forming a semiconductor nitride layer on a sidewall of the contact opening, performing a densification process on the semiconductor nitride layer to form a densified semiconductor nitride layer, forming a silicide layer on an exposed surface of the S/D region in the contact opening, forming a contact plug in the contact opening, and forming a via structure in the contact plug.