Contact Plug Sealing in Semiconductor Dielectrics to Prevent Cracks
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Solution Overview
Problem
The existing semiconductor manufacturing processes face challenges in achieving a reliable and defect-free interface between dielectric layers and contacts, which can lead to crack formation and device defects.
Innovation Solution
A method is introduced that involves forming an opening in a dielectric layer, depositing a first contact material, followed by a second contact material, and performing an ion implantation process on the dielectric layer. This process causes the dielectric layer to expand, forming a seal with the second contact material and preventing chemical slurry from penetrating during planarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional planarization processes are used without ion implantation, then the manufacturing process is simpler and faster, but cracks form at the interface between dielectric layers and contacts leading to device defects
Solution Approach 1:
Ion implantation is performed as a preliminary action before planarization to modify the dielectric layer properties in advance. This pre-treatment creates a more compliant dielectric structure that prevents crack formation during subsequent planarization, thereby improving interface reliability without adding significant complexity to the overall process flow.
Solution Approach 2:
The ion implantation process changes the physical and chemical parameters of the dielectric layer, including its mechanical compliance and stress characteristics. By modifying these parameters beforehand, the dielectric layer becomes more resistant to cracking during planarization, resolving the contradiction between reliability and process complexity.
2Reliability
If ion implantation is performed on the dielectric layer, then crack formation is reduced and interface reliability is improved, but the manufacturing process becomes more complex and time-consuming
Solution Approach 1:
Ion implantation is applied selectively to specific regions of the dielectric layer where cracks are most likely to form, rather than treating the entire wafer uniformly. This partial application reduces the overall process time and complexity while still achieving the reliability improvement in critical areas, thereby mitigating the impact on manufacturing throughput.
3Reliability
If the dielectric layer is made more compliant to prevent cracking, then interface reliability improves, but the structural integrity and mechanical strength may be compromised
Solution Approach 1:
The ion implantation creates local quality changes in the dielectric layer, making specific regions more compliant to prevent cracking at critical interfaces. The bulk of the dielectric layer retains its original mechanical strength, thus achieving both improved interface reliability and maintained overall structural integrity through spatially differentiated properties.
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 proposed method effectively reduces crack formation and device defects by creating a secure seal between the dielectric layer and the contact material, thereby improving the overall performance and reliability of semiconductor devices.
Implementation Method 1
performing an ion implantation process on the dielectric layer. The ion implantation may cause a volume expansion of the dielectric layer
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.