Bent Fin Layout for Wider Gate Fill Windows in FinFETs
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Solution Overview
Problem
The scaling down of semiconductor devices, such as FinFETs, poses challenges in filling and removing materials between closely spaced fins, leading to device defects and reduced performance due to increased complexity in gate formation processes.
Innovation Solution
Implementing bent fins to increase spacing between adjacent fins, allowing for improved gate formation process windows by determining the suitability of fins for bending based on spacing arrangements and subsequent planarization and annealing processes to enhance material deposition and removal efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If fin-to-fin spacing is reduced to increase device density, then functional density increases, but material filling and removal between fins becomes challenging leading to device defects
Solution Approach 1:
The patent introduces a vertical dimension to the fin structure by creating bent fins that extend at angles relative to the substrate. This dimensional change increases the spacing between fins in the horizontal plane, providing adequate room for material deposition and removal processes while maintaining high device density through the angled configuration.
Solution Approach 2:
The patent changes the geometric parameters of the fin structure by bending fins at specific angles (e.g., 45 degrees) relative to the substrate. This parameter modification transforms the traditional vertical fin geometry into an angled configuration, thereby increasing inter-fin spacing and improving manufacturability without sacrificing device density.
2Device complexity
If conventional gate formation processes are used with closely spaced fins, then fabrication complexity is reduced, but incomplete material fill-in or removal leads to device defects and reduced yield
Solution Approach 1:
The patent performs preliminary action by pre-bending the fins to angled configurations before subsequent gate formation processes. This preliminary geometric adjustment ensures that adequate spacing is established in advance, allowing standard material deposition and removal processes to complete successfully without causing defects, thereby improving device yield.
Solution Approach 2:
The patent applies curvature to the fin structures by bending them at angled orientations rather than maintaining straight vertical configurations. This curved geometry creates increased spacing between adjacent fins, enabling complete material fill-in and removal while maintaining fabrication process simplicity.
3Manufacturing precision
If fin spacing is increased to improve material deposition, then device density decreases, but bent fin geometry can maintain density while improving process window
Solution Approach 1:
The patent applies local quality by creating bent fins with specific angle configurations (e.g., 45 degrees) that optimize spacing in critical regions where material deposition occurs, while maintaining compact overall device layout. This localized geometric modification improves the process window for material deposition without requiring uniform increase in spacing across the entire device structure.
Solution Approach 2:
The patent introduces dynamic geometry to the fin structures by bending them at angled orientations, transforming the static vertical fin configuration into a dynamic angled structure. This dynamic geometric arrangement increases spacing in the horizontal dimension, improving material deposition capabilities while maintaining high device density through optimized spatial utilization.
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 of forming bent fins increases the process window for filling and removing gate materials, reducing defects and improving device performance by expanding the spacing between fins, thus facilitating more efficient semiconductor device fabrication.
Implementation Method 1
annealing the workpiece to bend the fin pair away from each other
Data Source
AI summary
Semiconductor devices and methods of forming the same are provided. In an embodiment, a semiconductor device includes a first fin extending along a first direction, a second fin extending parallel to the first fin, and a gate structure over and wrapping around the first fin and the second fin, the gate structure extending along a second direction perpendicular to the first direction. The first fin bents away from the second fin along the second direction and the second fin bents away from the first fin along the second direction.