Source/Drain Cap Layer Layout for FinFET Etch Protection
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Solution Overview
Problem
The semiconductor industry faces challenges in forming reliable semiconductor devices as feature sizes decrease, making fabrication processes increasingly difficult due to the need for precise control and complex processing steps.
Innovation Solution
A method for forming semiconductor device structures involves patterning fins using photolithography and self-aligned processes, forming isolation layers, gate structures, stressors, and cap layers to enhance device performance and prevent damage during etching, while using chemical vapor deposition and etching processes to achieve precise control over device dimensions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency and cost are improved, but fabrication process difficulty and device reliability worsen
Solution Approach 1:
A cap layer is formed over the source and drain structures before subsequent processing steps. This preliminary protective action prevents damage to the source/drain regions during etching and other fabrication processes, thereby maintaining device reliability even as feature sizes decrease and processing becomes more challenging
Solution Approach 2:
The cap layer serves as a protective cushion that absorbs or mitigates the harmful effects of subsequent etching processes on the source and drain structures. By placing this protective layer beforehand, the patent prevents potential damage that would otherwise occur during normal fabrication流程, thus preserving device reliability at smaller dimensions
2Productivity
If feature sizes continue to decrease to increase functional density, then production efficiency and cost are improved, but manufacturing precision requirements worsen
Solution Approach 1:
The cap layer is formed as a preliminary protective structure before critical etching steps. This preliminary action establishes a controlled reference structure that helps maintain manufacturing precision by providing a defined layer to work from, reducing variability in subsequent processing steps
Solution Approach 2:
The cap layer acts as an intermediary between the source/drain structures and the etching process. It mediates the interaction by providing a controlled interface that protects the underlying structures while allowing precise etching of upper layers, thereby maintaining manufacturing precision at smaller feature sizes
3Reliability
If complex processing steps are used to maintain device performance at smaller sizes, then device reliability is improved, but fabrication process complexity worsens
Solution Approach 1:
By forming the cap layer as a preliminary protective structure, the patent simplifies subsequent processing steps. Instead of requiring complex in-situ protection methods during etching, the preliminary cap layer provides straightforward protection, reducing overall fabrication complexity while maintaining device reliability
Solution Approach 2:
The cap layer serves as a simple intermediary structure that enables reliable source/drain protection without requiring complex processing sequences. This single intermediate layer simplifies the fabrication process compared to alternative approaches that might require multiple protective layers or complex etching masks
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
This approach allows for the formation of reliable semiconductor devices with improved precision and efficiency, enabling the production of smaller and more complex circuits while maintaining device performance and reliability.
Implementation Method 1
the cap layer prevents the source structure and the drain structure from damage during etching
Implementation Method 2
using chemical vapor deposition and etching processes to achieve precise control over device dimensions
Data Source
AI summary
A semiconductor device structure is provided. The semiconductor device structure includes a first fin structure extended above a substrate along a first direction, and a first gate structure formed over the first fin structure along a second direction. The semiconductor device structure includes a first source/drain (S/D) structure formed over the first fin structure and adjacent to the first gate structure, and a cap layer formed on and in direct contact with the first S/D structure. The semiconductor device structure includes an isolation structure adjacent to the first gate structure and the first S/D structure along the first direction. The isolation structure extends from the first gate structure to the first S/D structure, and the first S/D structure has a protruding portion toward to the isolation structure, and the protruding portion of the first S/D structure is separated from the isolation structure by the cap layer.