ECR Plasma Fin Etching for Nanometer CD Profile Control
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Solution Overview
Problem
As the semiconductor industry advances to nanometer technology nodes, precise critical dimension (CD) control is required for further improvements in FinFET devices, particularly in three-dimensional designs like multi-gate field effect transistors, to achieve higher device density and performance.
Innovation Solution
The use of an electron cyclotron resonance (ECR) plasma etching apparatus with adjustable coil currents and varying source gases, such as chlorine and fluorine-based plasmas, to control the profile of fin structures during the etching process, allowing for precise shaping of fin structures and improving device performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional etching methods are used for fin structure fabrication, then the manufacturing process is simpler, but the critical dimension control precision is insufficient for nanometer technology nodes
Solution Approach 1:
The patent applies dynamics by making the etching process adjustable through real-time modification of plasma parameters (power, pressure, gas composition) and coil currents during etching. This enables dynamic control of the etching rate and profile formation, allowing precise critical dimension control while adapting to different fin structure requirements without requiring completely different etching tools or processes.
Solution Approach 2:
The patent utilizes parameter changes by systematically varying plasma etching parameters including power levels, pressure conditions, gas composition (chlorine/fluorine ratios), and coil currents. These parameter modifications enable precise control over etching rate, anisotropy, and profile shape, achieving the required critical dimension precision for nanometer nodes through optimized parameter combinations rather than fundamental process changes.
2Reliability
If the fin structure profile is precisely controlled during etching, then device performance metrics improve, but the etching process requires more complex control mechanisms
Solution Approach 1:
The patent implements feedback control by using in-situ metrology tools (such as optical or physical vapor deposition monitoring) to measure the fin structure profile during or between etching steps. These measurements feed back to adjust plasma parameters and coil currents in real-time, ensuring the etched profile matches the target geometry. This closed-loop control improves device performance reliability while managing process complexity through automated feedback mechanisms.
Solution Approach 2:
The patent replaces traditional mechanical profile control methods with electromagnetic field-based control. By using electron cyclotron resonance (ECR) with adjustable coil currents, the system controls plasma distribution and etching profiles through electromagnetic fields rather than mechanical means. This substitution enables more precise and flexible profile control without the mechanical complexity of moving parts or physical adjustment mechanisms.
3Manufacturing precision
If electron cyclotron resonance plasma etching with adjustable parameters is used, then fin structure profile precision is improved, but the equipment complexity and operational difficulty increase
Solution Approach 1:
The patent applies universality by designing the ECR plasma etching system to perform multiple functions through a single integrated platform. The same apparatus with adjustable coil currents and plasma parameters can etch various fin structures with different profiles, dimensions, and materials. This multi-functionality reduces the need for multiple specialized tools and simplifies operation by providing a unified interface for diverse etching requirements, despite the underlying complexity of the ECR system.
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 enables precise control over the channel and source/drain profiles, enhancing device performance metrics like driving current, threshold voltage, and switching speed, while maintaining geometrical requirements, thus improving the yield and performance of FinFET devices.
Implementation Method 1
The use of an electron cyclotron resonance (ECR) plasma etching apparatus with adjustable coil currents and varying source gases
Implementation Method 2
a plasma condition of the ECR plasma etching is changed during the etching the target layer
Data Source
AI summary
In a method of manufacturing a semiconductor device, a mask pattern is formed over a target layer to be etched, and the target layer is etched by using the mask pattern as an etching mask. The etching is performed by using an electron cyclotron resonance (ECR) plasma etching apparatus, the ECR plasma etching apparatus includes one or more coils, and a plasma condition of the ECR plasma etching is changed during the etching the target layer by changing an input current to the one or more coils.