FinFET Channel Doping Structure for Uniform Profiles and Mobility
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Solution Overview
Problem
Existing FinFET devices face challenges with dopant concentration uniformity and carrier mobility due to high levels of crystal lattice defects and ionized impurity scattering caused by traditional fin top implantation methods, leading to degraded device performance and increased short-channel effects.
Innovation Solution
A FinFET structure with a dopant concentration lower than 1E17/cm3 in the channel region is achieved through a manufacturing method involving angled implantation techniques, which reduces dopant concentration variability and minimizes lattice defects, ensuring uniform dopant distribution in well and anti-punch through regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If traditional fin top implantation methods are used, then dopant concentration can be introduced into the fin, but high levels of crystal lattice defects and ionized impurity scattering occur, degrading carrier mobility
Solution Approach 1:
The patent changes the implantation angle from vertical (top surface) to angled (sidewall), introducing a dimensional change in the doping approach. This angled implantation method delivers dopants to the fin region while avoiding direct top surface bombardment, thereby reducing crystal lattice defects and ionized impurity scattering that degrade carrier mobility.
2Quantity of substance
If traditional fin top implantation methods are used, then dopant concentration is introduced, but dopant concentration uniformity deteriorates due to high levels of crystal lattice defects
Solution Approach 1:
The patent employs angled implantation instead of vertical top surface implantation. This dimensional change in the doping approach enables more uniform dopant distribution by delivering dopants from the sidewall direction, avoiding the non-uniformity caused by top surface implantation and associated crystal lattice defects.
3Quantity of substance
If traditional fin top implantation methods are used, then doping is achieved, but short-channel effects are enhanced due to degraded device performance
Solution Approach 1:
The patent uses angled implantation to deliver dopants to the fin region, which maintains lower parasitic doping in the channel compared to top surface implantation. This dimensional change in doping approach preserves channel quality and reduces short-channel effects by avoiding the degradation of device performance associated with traditional methods.
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 enhances carrier mobility and suppresses short-channel effects, resulting in improved device performance by maintaining low dopant concentrations in critical regions and achieving uniform dopant profiles.
Implementation Method 1
doping the semiconductor fin by an angle implantation operation
Data Source
AI summary
Present disclosure provides a FinFET structure, including a substrate, a fin protruding from the substrate, including a first portion and a second portion below the first portion, wherein the first portion includes a first dopant concentration of a dopant, and the second portion includes a second dopant concentration of the dopant, the second dopant concentration is greater than the first dopant concentration, a gate over the fin, wherein the second portion of the fin is below a bottom surface of the gate, and an insulating layer over the substrate and proximal to the second portion of the fin, wherein at least a first portion of the insulating layer includes a third dopant concentration of the dopant, the third dopant concentration is greater than the first dopant concentration.