FinFET Doped Region Migration to Reduce Punch Through Leakage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
FinFET semiconductor devices face performance-limiting punch through leakage currents, particularly at the bottom of fins near local isolation regions, as device dimensions shrink, necessitating more efficient techniques to reduce these detrimental currents.
Innovation Solution
The method involves forming trenches in a semiconducting substrate to create fins, followed by the deposition of a doped insulating layer, where heating causes dopant material to migrate into the covered portions of the fins, creating a doped region under the exposed portions, thereby reducing punch through leakage currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If device dimensions are reduced to improve integration density and switching speed, then productivity and operating speed are improved, but punch through leakage currents increase
Solution Approach 1:
The patent applies local quality by forming a doped region specifically at the bottom portion of the fin structure where punch-through leakage occurs. This localized doping creates a potential barrier precisely where needed (at the source-drain junction interface) without affecting other regions of the device, thereby reducing leakage currents while maintaining the scaled dimensions for high integration density.
Solution Approach 2:
The doped region is formed as a preliminary structure before final device operation. By pre-establishing the doped region at the fin bottom during fabrication, the potential barrier is created in advance to prevent punch-through leakage during device operation, addressing the leakage issue before it manifests in the scaled device.
2Speed
If channel length is reduced to improve switching speed, then operating speed is improved, but short channel effects worsen
Solution Approach 1:
The doped region is localized at the bottom portion of the fin structure, creating a specific potential barrier zone that addresses short channel effects precisely where they occur (at the source-drain interface) without affecting the overall channel characteristics needed for high switching speed.
3Productivity
If separation between source and drain is reduced to increase FET density, then productivity is improved, but electrical potential control deteriorates
Solution Approach 1:
By creating a doped region specifically at the source-drain interface region (bottom of the fin), the patent establishes a localized potential barrier that prevents electrical potential interference between source and drain, enabling closer spacing while maintaining proper potential control.
Solution Approach 2:
The doped region acts as an intermediary structure between the source and drain regions. This intermediate doped zone creates a potential barrier that mediates the electrical interaction between source and drain, preventing direct potential interference even when the separation distance is reduced for higher density.
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
This approach effectively reduces punch through leakage currents by creating a doped region that mitigates electrical potential interference between the source and drain, enhancing the performance of FinFET devices by minimizing undesirable current flow.
Implementation Method 1
performing at least one process operation to heat at least the doped layer of insulating material to cause a dopant material in the doped layer of insulating material to migrate from the doped layer of insulating material into the covered portions of the fins
Data Source
AI summary
Disclosed are methods of forming bulk FinFET semiconductor devices to reduce punch through leakage currents. One example includes forming a plurality of trenches in a semiconducting substrate to define a plurality of spaced-apart fins, forming a doped layer of insulating material in the trenches, wherein an exposed portion of each of the fins extends above an upper surface of the doped layer of insulating material while a covered portion of each of the fins is positioned below the upper surface of the doped layer of insulating material, and performing a process operation to heat at least the doped layer of insulating material to cause a dopant material in the doped layer to migrate from the doped layer of insulating material into the covered portions of the fins and thereby define a doped region in the covered portions of the fins that is positioned under the exposed portions of the fins.