FinFET Isolation Feature Structure for Smaller Gate-Region Patterning
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Solution Overview
Problem
The manufacturing of advanced semiconductor devices, such as FinFETs, faces challenges in forming features at smaller sizes due to limitations in photolithography and etching processes, complicating the fabrication process.
Innovation Solution
A method involving the use of capping layers to reduce the dimensions of openings in semiconductor structures, allowing for the formation of smaller features by fine-tuning their dimensions through controlled deposition and etching processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional photolithography and etching processes are used, then manufacturing process simplicity is maintained, but manufacturing precision deteriorates due to inability to form features at smaller sizes
Solution Approach 1:
The fabrication process is divided into multiple sequential steps: forming initial openings, depositing first capping layer, etching recesses, depositing second capping layer, and performing planarization. Each step progressively refines the feature dimensions, enabling precise control of final feature size that cannot be achieved with conventional single-step photolithography and etching
Solution Approach 2:
Capping layers are deposited in advance before final patterning steps. The first capping layer is deposited over initial openings, and the second capping layer is deposited over the structure with recesses, allowing subsequent planarization to precisely define final feature dimensions. This preliminary deposition enables better control over final feature size and shape
2Productivity
If feature size is reduced to increase functional density, then productivity is improved, but manufacturing precision deteriorates due to process limitations
Solution Approach 1:
The process utilizes multiple deposition layers with different materials and thicknesses to control feature dimensions. By adjusting the thickness of capping layers and the depth of etched recesses, precise control over final feature size is achieved. This multi-parameter approach enables reduced feature size while maintaining manufacturing precision
Solution Approach 2:
The invention transitions from two-dimensional planar patterning to three-dimensional structured fabrication with recesses and multiple capping layers. This vertical dimensionality allows precise control of horizontal feature dimensions through the interaction of layer thicknesses and recess depths, enabling smaller features with better dimensional control
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
Enables the fabrication of semiconductor devices with smaller and more precise features, improving manufacturing efficiency and device performance by overcoming the limitations of conventional photolithography and etching techniques.
Implementation Method 1
deposition processes
Implementation Method 2
etching processes
Data Source
AI summary
A semiconductor device structure includes a fin structure over a semiconductor substrate and a dummy gate stack formed over the fin structure and having a first sidewall and an opposite second sidewall. The semiconductor device structure also includes a first and second source or drain (S/D) structures in the fin structure and respectively adjacent to the first and second sidewalls of the dummy gate stack. The semiconductor device structure further includes an isolation feature formed in the fin structure below the dummy gate stack and having a third sidewall and an opposite fourth sidewall. A first end of the third sidewall overlaps the first end of the fourth sidewall. A second end of the third sidewall is in direct contact with a bottom of the dummy gate stack. A second end of the fourth sidewall is separated from the bottom of the dummy gate stack.