Source/Drain Contact Liner Structure for Low-Resistance Semiconductor Scaling
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Solution Overview
Problem
The challenge in semiconductor manufacturing lies in forming reliable semiconductor devices with increasingly smaller sizes, as fabrication processes become more difficult due to decreased feature sizes, affecting production efficiency and cost.
Innovation Solution
A method involving the formation of semiconductor fins with gate structures, epitaxy features, and dielectric layers to enhance carrier mobility, combined with a gate replacement process and the use of a dielectric liner to protect conductive structures during etching, allowing for enlarged contact holes and reduced resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes are decreased to increase functional density, then production efficiency is improved and costs are lowered, but fabrication processes become more difficult to perform
Solution Approach 1:
A dielectric liner is formed on the source/drain contact before the conductive structure is deposited. This preliminary action of adding the liner layer before main structure formation enables better process control during subsequent etching operations and maintains fabrication reliability even as feature sizes decrease, thus addressing the worsening fabrication difficulty while preserving productivity gains from scaling.
Solution Approach 2:
The dielectric liner acts as an intermediary layer between the source/drain contact and the conductive structure. This intermediary layer facilitates controlled etching processes and improves interface quality, making fabrication easier to perform while maintaining the benefits of smaller feature sizes for higher productivity.
2Area of stationary object
If feature sizes are decreased to increase functional density, then chip area is reduced, but reliability of semiconductor devices becomes more difficult to maintain
Solution Approach 1:
The dielectric liner is formed in advance on the source/drain contact before subsequent processing steps. This preliminary formation ensures proper interface preparation and etching control, maintaining device reliability even as chip area is reduced through scaling to higher functional densities.
Solution Approach 2:
The dielectric liner serves as a protective intermediary between the source/drain contact and the conductive structure, ensuring reliable interfaces and controlled etching. This intermediary layer maintains device reliability while enabling further scaling down of chip area to increase functional density.
3Reliability
If contact holes are enlarged to reduce resistance, then carrier mobility is improved, but process control becomes more difficult
Solution Approach 1:
The dielectric liner acts as a mediator during the etching process, enabling precise control of contact hole dimensions. This intermediary layer allows for enlarged contact holes that improve carrier mobility while maintaining manufacturing precision through better etching control and interface definition.
Solution Approach 2:
The introduction of the dielectric liner changes the physical and chemical parameters of the contact interface, enabling optimized etching conditions. This parameter change allows contact holes to be enlarged for improved carrier mobility while maintaining precise process control through enhanced interface properties.
Data Source
AI summary
A semiconductor device includes a semiconductor substrate, a gate electrode, a source/drain contact, a conductive structure, and a dielectric liner. The semiconductor substrate has a channel region and a source/drain region. The gate electrode is over the channel region. The source/drain contact is over the source/drain region. The conductive structure is over a top surface of the source/drain contact. The dielectric liner surrounds the conductive structure and is over the top surface of the source/drain contact.