Contact Plug Sealing Structure Against CMP Chemical Penetration
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Solution Overview
Problem
The semiconductor industry faces challenges in forming reliable interfaces between dielectric layers and contacts, leading to crack formation and device defects due to the penetration of chemicals during planarization processes, which affects the integration density and performance of semiconductor devices.
Innovation Solution
A method involving the formation of an opening in a dielectric layer, depositing a first contact material, followed by a second contact material, and performing an ion implantation process to expand the dielectric layer, creating a seal that prevents chemical penetration and reduces crack formation between the contact and dielectric layer, thereby improving device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If planarization process is performed to flatten the surface, then surface flatness is improved, but chemicals penetrate between contact and dielectric layer causing cracks and defects
Solution Approach 1:
A dielectric liner is introduced as an intermediary layer between the contact material and the first dielectric layer. This liner acts as a barrier that prevents chemicals from penetrating into the interface during planarization, thereby eliminating cracks and defects while maintaining surface flatness. The liner serves as a protective mediator that isolates the contact-dielectric interface from harmful chemical exposure.
2Reliability
If ion implantation is performed to expand dielectric layer and create seal, then sealing effectiveness is improved, but process complexity increases
Solution Approach 1:
Ion implantation is used to change the physical and chemical parameters of the dielectric layer, causing it to expand and form a seal that prevents chemical penetration. By modifying the dielectric layer's density and volume through ion bombardment, the process creates an effective barrier without requiring additional structural layers, thus managing complexity while improving sealing.
3Reliability
If multiple contact materials are deposited to form contact structure, then contact performance is improved, but interface vulnerability to chemical penetration increases
Solution Approach 1:
The dielectric liner serves as a protective intermediary between the multi-layer contact structure and the first dielectric layer. This liner prevents chemicals from reaching and degrading the contact materials during planarization, thereby preserving the integrity and performance of the complex contact structure while allowing multiple contact material layers to be deposited for optimized electrical performance.
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 method enhances the sealing between dielectric and contact materials, reducing defects and improving the performance of semiconductor devices by preventing chemical penetration during planarization processes, thus maintaining device integrity and efficiency.
Implementation Method 1
performing an ion implantation process on the dielectric layer. The ion implantation may cause a volume expansion of the dielectric layer, which may form a seal between the ion implanted dielectric layer and the contact
Data Source
AI summary
Methods for improving sealing between contact plugs and adjacent dielectric layers and semiconductor devices formed by the same are disclosed. In an embodiment, a semiconductor device includes a first dielectric layer over a conductive feature, a first portion of the first dielectric layer including a first dopant; a metal feature electrically coupled to the conductive feature, the metal feature including a first contact material in contact with the conductive feature; a second contact material over the first contact material, the second contact material including a material different from the first contact material, a first portion of the second contact material further including the first dopant; and a dielectric liner between the first dielectric layer and the metal feature, a first portion of the dielectric liner including the first dopant.