FinFET Cut Metal Gate Helmet Structure for Etch Damage Prevention
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Solution Overview
Problem
As semiconductor devices continue to integrate more components into a given area through reduced minimum feature sizes, challenges arise in the fabrication of fin field effect transistors (FinFETs) due to the complexity of forming and patterning semiconductor fins, isolation regions, and metal gates, which affect the overall device performance and reliability.
Innovation Solution
A method for fabricating FinFETs involving the formation of fins, isolation regions, and metal gates through advanced photolithography and etching processes, including double-patterning techniques, selective epitaxial growth, and the use of high-k gate dielectrics and conductive materials to enhance device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If minimum feature size is reduced to increase integration density, then more components can be integrated into a given area, but fabrication complexity and difficulty increase
Solution Approach 1:
The patent applies segmentation by dividing the gate electrode formation into multiple discrete steps: forming a first gate electrode layer, patterning it to create first gate electrodes, then forming and patterning a second gate electrode layer to create second gate electrodes. This multi-stage segmentation approach enables precise control of complex FinFET structures while maintaining integration density benefits from reduced feature sizes.
Solution Approach 2:
The patent utilizes vertical dimensionality by forming FinFET structures with raised fins that extend vertically from the substrate. The gate electrodes wrap around these vertical fins, creating a three-dimensional transistor structure. This dimensional transition from planar to vertical architecture increases effective channel area and integration density without proportionally increasing lithographic feature size requirements.
2Quantity of substance
If minimum feature size is reduced to increase integration density, then more components can be integrated into a given area, but manufacturing precision requirements increase
Solution Approach 1:
The patent employs preliminary action through self-aligned processes where the first gate electrode structure serves as a alignment reference for subsequent second gate electrode formation. The mandrel structures and spacer formations are pre-positioned to define precise locations for later etching and deposition steps, ensuring high patterning precision is maintained even as feature sizes are reduced for increased integration density.
Solution Approach 2:
The patent uses intermediary structures such as mandrels and spacers that facilitate precise pattern transfer. These intermediary elements act as temporary placeholders and alignment guides during the multi-step patterning process, enabling accurate formation of narrow FinFET features without directly requiring high-precision lithography at every step, thus maintaining manufacturing precision while achieving high integration density.
3Quantity of substance
If advanced photolithography and etching processes are used to form FinFETs, then integration density improves, but device reliability challenges increase
Solution Approach 1:
The patent applies parameter changes by transitioning from conventional planar transistors to FinFET structures with controlled fin height, width, and spacing parameters. The raised fin geometry and wrapped gate configuration modify the electrical field distribution and carrier transport characteristics, improving device performance and reliability metrics such as drive current and threshold voltage control while maintaining high integration density achieved through reduced feature sizes.
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 enables the formation of high-performance FinFETs with improved integration density and reliability by ensuring precise patterning and deposition of semiconductor layers, resulting in enhanced electrical properties and reduced defects.
Implementation Method 1
semiconductor devices are typically fabricated by sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material over a semiconductor substrate
Implementation Method 2
sequentially depositing insulating or dielectric layers, conductive layers, and semiconductor layers of material
Implementation Method 3
patterning the various material layers using lithography to form circuit components and elements thereon
Implementation Method 4
advanced photolithography and etching processes
Implementation Method 5
selective epitaxial growth
Data Source
AI summary
A semiconductor device including a fin field effect transistor (FinFET) with a cut metal gate (CMG) and a method of manufacturing the semiconductor device are described herein. The method includes forming a CMG protective helmet structure at a top portion of a CMG dummy gate plug formed within a semiconductor substrate. The CMG protective helmet structure prevents consumption and damage of a dummy filler material in a CMG region and prevents undesirable polymer/residue byproducts from forming on top surfaces of epitaxial regions of the FinFET during etching processes.