Plasma Doping Method for FinFET Conformal Distribution
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Solution Overview
Problem
Conventional doping methods, such as ion doping and ion-assisted deposition, fail to achieve uniform dopant distribution across the three-dimensional structure of FinFET-type semiconductor devices, particularly at the top, side, and bottom portions, due to uneven ion irradiation and lack of conformal doping.
Innovation Solution
A plasma doping method using microwave-generated plasma, followed by annealing, to implant dopant ions into the semiconductor substrate, ensuring conformal distribution of dopants across the three-dimensional structure by utilizing a radial line slot antenna and controlling microwave power density and annealing temperature.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional ion doping or ion-assisted deposition is used, then doping can be performed on semiconductor substrates, but uniform dopant distribution across three-dimensional structures cannot be achieved
Solution Approach 1:
The invention changes the fundamental parameters of the doping process by using plasma doping instead of conventional ion doping. This involves using a plasma source with specific power density (0.1-10 W/cm²) and pressure conditions (10-1000 mTorr) to generate a high concentration of reactive species that can conformally deposit dopants on three-dimensional structures. The plasma parameters are optimized to achieve both uniformity and three-dimensional coverage.
Solution Approach 2:
The invention replaces the mechanical ion implantation system with a plasma-based chemical deposition system. Instead of physically accelerating ions into the substrate, the process uses plasma chemistry to deposit dopant atoms that then diffuse into the substrate. This substitution enables conformal coverage of complex three-dimensional structures while maintaining uniform dopant distribution.
2Manufacturing precision
If plasma doping is used to achieve conformal doping, then uniform dopant distribution can be obtained, but the process complexity increases
Solution Approach 1:
The plasma doping apparatus is designed to perform multiple functions: generating plasma, controlling pressure, regulating gas flow, and heating the substrate. By integrating these functions into a single platform, the system achieves conformal doping capability without proportionally increasing overall system complexity. The same plasma source can be used for different doping scenarios by adjusting parameters.
Solution Approach 2:
The invention simplifies the plasma generation system by operating at relatively low power densities (0.1-10 W/cm²) and moderate pressures (10-1000 mTorr), which are easier to control and maintain than high-power plasma sources. These parameter choices reduce the complexity of plasma generation while still achieving the desired conformal doping effect.
3Productivity
If high power density is used in plasma doping, then doping efficiency increases, but non-uniform doping and substrate damage occur
Solution Approach 1:
The invention identifies and implements an optimal parameter window for plasma doping: power density of 0.1-10 W/cm² and pressure of 10-1000 mTorr. Within this window, the plasma maintains high reactivity for efficient doping while avoiding the excessive ion bombardment that causes non-uniformity and substrate damage. This parameter optimization balances efficiency and uniformity.
Solution Approach 2:
The invention uses a moderate power density range rather than maximum possible power, accepting slightly lower doping efficiency in exchange for uniform dopant distribution and substrate integrity. This partial action approach avoids the harmful effects of excessive power while still achieving practical doping rates.
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 method achieves conformal doping by uniformly distributing dopants across the FinFET-type semiconductor device, improving the uniformity of dopant concentrations and depths, even in complex three-dimensional structures, through the combination of plasma doping and subsequent annealing processing.
Implementation Method 1
generating plasma within a processing container using a microwave thereby performing a plasma doping processing on the processing target substrate
Implementation Method 2
generating plasma within a processing container using a microwave
Implementation Method 3
annealing the processing target substrate which has been subjected to the plasma doping processing
Data Source
AI summary
Disclosed is a plasma doping apparatus and a plasma doping method for performing a doping on a processing target substrate by implanting dopant ions into the processing target substrate. The plasma doping method includes a plasma doping processing performed on the processing target substrate held on a holding unit within a processing container by generating plasma using a microwave. The plasma doping method also includes an annealing processing which is performed on the processing target substrate which has been subjected to the plasma doping processing.