Plug Structure With Segmented Barrier Layer For Contact Resistance
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Solution Overview
Problem
As semiconductor devices miniaturize, filling barrier layers and low resistivity materials into contact holes becomes challenging, affecting the performance of contact plugs in field effect transistors, particularly due to high contact resistance and adhesion issues between plugs.
Innovation Solution
A plug structure and process involving a first sputtering process to remove the bottom part of a barrier layer, while maintaining the sidewall part, to enhance the connection between contact plugs and improve filling efficiency, using an argon sputtering process to reduce contact resistance and improve adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional barrier layer filling process is used, then the barrier layer can be formed in the contact hole, but the contact resistance between contact plugs increases and adhesion deteriorates
Solution Approach 1:
The barrier layer is segmented into two distinct parts: a bottom part that is removed to reduce contact resistance, and a sidewall part that remains to provide adhesion and structural support. This segmentation allows each part to fulfill its specific function optimally without compromising the other.
Solution Approach 2:
The bottom part of the barrier layer is extracted and removed through a sputtering process. This extraction eliminates the source of high contact resistance while preserving the sidewall part that provides necessary adhesion between the contact plugs.
2Reliability
If a dual layer sidewall structure is used, then adhesion is enhanced, but the process complexity increases
Solution Approach 1:
The barrier layer structure is made dynamic through selective removal. The process transitions from a static dual-layer structure to a dynamic configuration where the bottom layer is removed and only the sidewall layer remains, adapting the structure to the specific functional requirements of each region.
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 process reduces contact resistance between contact plugs, enhances adhesion, and improves the top critical dimension and filling of the barrier layer, leading to better performance of semiconductor components.
Implementation Method 1
performs a sputtering process to remove at least part of a bottom part of a barrier layer
Implementation Method 2
performs a first sputtering process to remove a bottom part of at least one layer of a barrier layer, so the contact resistance (Rc) between each of a first contact plug and a second contact plug can be reduced. The adhesion between the first contact plug and the second contact plug can be enhanced
Data Source
AI summary
A plug structure including a first dielectric layer, a second dielectric layer, a barrier layer and a second plug is provided. The first dielectric layer having a first plug therein is located on a substrate, wherein the first plug physically contacts a source/drain in the substrate. The second dielectric layer having an opening exposing the first plug is located on the first dielectric layer. The barrier layer conformally covers the opening, wherein the barrier layer has a bottom part and a sidewall part, and the bottom part is a single layer and physically contacts the first plug while the sidewall part is a dual layer. The second plug fills the opening and on the barrier layer. Moreover, a process of forming a plug structure is also provided.