GAA FET Fin Stack Layout for Dense Nodes and Gate Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As the semiconductor industry advances to nanometer technology process nodes, there is a challenge in fabricating FinFETs and GAA FETs with improved performance and density, particularly in ensuring effective gate control over the channel region.
Innovation Solution
The method involves forming alternating stacks of semiconductor layers with different lattice constants over a substrate, patterning these layers into fin structures, and then embedding them in insulating layers to create a gate-all-around (GAA) FET structure. This approach allows for enhanced control over the channel region and improved device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If FinFET structure is used to increase device density, then device density is improved, but gate control over the channel region deteriorates
Solution Approach 1:
The patent transitions from planar 2D gate control to three-dimensional gate-all-around control by wrapping the gate electrode completely around the channel region. This dimensional change allows the gate to control carrier flow from top, bottom, and sides, achieving effective control even as device density increases and dimensions scale down to nanometer nodes.
Solution Approach 2:
The gate electrode is nested around the channel region in a concentric configuration, with the gate dielectric layer interposed between them. This nested structure enables the gate to surround and control the channel from all directions, providing superior electrostatic control compared to conventional planar or FinFET structures.
2Quantity of substance
If transistor dimensions are scaled down to sub 10-15 nm nodes, then device density is improved, but manufacturing precision requirements worsen
Solution Approach 1:
The patent employs segmented alternating stacks of semiconductor layers with different lattice constants, which are selectively removed to form the channel region. This segmentation approach, combined with self-aligned processes, enables precise dimensional control at sub-10nm nodes by using the layered structure as a template for subsequent processing steps.
Solution Approach 2:
The patent utilizes changes in lattice constant parameters between alternating semiconductor layers to enable selective etching and formation of the channel region. By carefully selecting materials with different lattice constants, the process achieves atomic-layer precision in defining the channel dimensions and position, meeting the stringent manufacturing precision requirements at advanced nodes.
3Reliability
If alternating stacks of semiconductor layers with different lattice constants are formed, then gate-all-around control is achieved, but device complexity increases
Solution Approach 1:
The alternating stacks of semiconductor layers with different lattice constants are formed preliminarily before the main device fabrication steps. This preliminary structuring serves as a self-aligned template that guides subsequent processing, reducing the need for additional alignment steps and simplifying the overall manufacturing process despite the complex final structure.
Solution Approach 2:
The alternating stack structure serves multiple functions: it defines the channel region geometry, provides self-alignment references for subsequent processing, and enables selective material removal to form the gate-all-around structure. This multi-functionality reduces the need for separate process steps, offsetting the initial structural complexity.
Data Source
AI summary
A method of manufacturing a semiconductor device includes forming a plurality of fin structures extending in a first direction over a semiconductor substrate. Each fin structure includes a first region proximate to the semiconductor substrate and a second region distal to the semiconductor substrate. An electrically conductive layer is formed between the first regions of a first adjacent pair of fin structures. A gate electrode structure is formed extending in a second direction substantially perpendicular to the first direction over the fin structure second region, and a metallization layer including at least one conductive line is formed over the gate electrode structure.