CPODE End Isolation Structure for Lower Parasitic Capacitance
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Solution Overview
Problem
The semiconductor industry faces challenges in scaling down semiconductor integrated circuits (ICs) while maintaining gate control and reducing short-channel effects, leading to increased complexity in manufacturing processes.
Innovation Solution
The implementation of a Continuous Poly On Diffusion Edge (CPODE) process, which involves forming a CPODE insulation structure between active regions, removing high-K gate dielectric layers from the end walls of this structure, and using a cut-metal process to pattern metal gate lines, thereby reducing parasitic capacitance and threshold voltage shifts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-K gate dielectric layers are present on the end walls of the CPODE insulation structure, then gate control is improved, but parasitic capacitance and threshold voltage shifts increase
Solution Approach 1:
The patent selectively removes the high-K gate dielectric layer from the end walls of the CPODE insulation structure while preserving it in other critical regions. This extraction eliminates the parasitic capacitance caused by the dielectric on the end walls, thereby resolving the harmful effect without compromising gate control in the active device regions.
Solution Approach 2:
The patent applies different dielectric configurations to different spatial locations: the high-K gate dielectric is retained in the channel region for effective gate control, while being removed from the end wall regions where it causes parasitic capacitance. This local differentiation optimizes both gate control and parasitic reduction.
2Productivity
If scaling down semiconductor IC dimensions is continued, then production efficiency is improved and costs are lowered, but manufacturing process complexity increases
Solution Approach 1:
The patent segments the high-K gate dielectric layer into two distinct regions: retained in the channel area for device functionality and removed from the end wall areas to eliminate parasitics. This segmentation allows the manufacturing process to address different regions with different requirements, managing complexity through structured differentiation.
Solution Approach 2:
The patent performs selective removal of the high-K gate dielectric from end walls at a specific stage in the fabrication process, before final device assembly. This preliminary action prevents parasitic capacitance from forming in the first place, avoiding the need for later corrective measures and simplifying subsequent manufacturing steps.
Data Source
AI summary
Provided are semiconductor devices and methods for fabricating such devices. An exemplary method includes forming a fin structure over a semiconductor material; forming a sacrificial layer over the semiconductor material; removing a portion of the fin structure and an overlying portion of the sacrificial layer located over the portion of the fin structure to form a trench; forming an insulation structure in the trench, wherein an adjacent portion of the sacrificial layer is adjacent an end wall of the insulation structure; removing the adjacent portion to form a cavity partially defined by the end wall; lining the cavity with a liner, wherein an end portion of the liner is located on the end wall of the insulation structure; filling the cavity with a fill material; removing the end portion of the liner to form an opening; and forming an end isolation structure in the opening.