Bent Fin Layout for FinFET Gate Fill and Removal
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Solution Overview
Problem
The scaling down of semiconductor devices, particularly FinFETs, faces 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 performing specific planarization and annealing processes to facilitate the bending of fins.
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 transitions from planar gate formation to three-dimensional bent fin structures. By bending the fins in a curved configuration rather than maintaining straight vertical orientation, the effective spacing between fins is increased in the lateral dimension while maintaining close vertical stacking, enabling material filling and removal processes to proceed effectively without defects
Solution Approach 2:
The patent modifies the geometric parameters of the fin structure by introducing curvature and bending angles. The fins are formed with specific bend radii and angles that optimize the spacing between adjacent fins, transforming the rigid straight-finned geometry into a flexible curved geometry that facilitates manufacturing processes while maintaining high device density
2Productivity
If conventional gate replacement processes are used with reduced fin spacing, then device scaling is achieved, but incomplete fill-in or removal of material leads to reduced device performance and yield
Solution Approach 1:
By implementing bent fin structures, the patent creates additional lateral space between fins that allows complete deposition and removal of gate materials. This dimensional change from straight to curved fins ensures that material processing can be completed thoroughly, eliminating defects that would otherwise reduce device yield during scaling operations
Solution Approach 2:
The bent fin structure is prepared in advance before gate material deposition. The curvature is intentionally designed and formed prior to the gate replacement process, pre-establishing the optimal spacing and geometry needed for complete material filling and removal, thereby preventing yield-loss defects before they occur
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 increased spacing between bent fins enhances the process window for filling and removing gate materials, thereby improving device performance and yield by facilitating more effective dummy and functional gate material deposition and removal.
Implementation Method 1
annealing the workpiece, wherein the annealing causes the fins to bend 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.