In-Sn-Zn-O Semiconductor Etching for Transistor Miniaturization
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Solution Overview
Problem
In—Sn—Zn—O-based oxide semiconductor layers are difficult to etch using wet etching methods, which limits miniaturization and controllability in semiconductor device manufacturing, as wet etching is isotropic and lacks precision.
Innovation Solution
The use of dry etching techniques with gases containing chlorine, such as Cl2, BCl3, or SiCl4, along with rare gases, oxygen, or fluorine, to selectively etch In—Sn—Zn—O-based semiconductor layers, allowing for the formation of island-shaped structures with controlled taper angles and minimal material removal, enabling miniaturization and improved controllability in transistor manufacturing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If wet etching is used to etch oxide semiconductor layers, then the etching process is simple and isotropic, but the manufacturing precision and controllability deteriorate, preventing miniaturization
Solution Approach 1:
The patent replaces wet etching (chemical/liquid-based) with dry etching (gas-phase plasma-based) to achieve superior etching precision and controllability. The dry etching process using chlorine-containing gases provides anisotropic etching that enables precise pattern formation for miniaturized devices, while maintaining ease of manufacture through established semiconductor fabrication techniques
Solution Approach 2:
The patent changes the etching parameters by using specific chlorine-containing gases (Cl2, BCl3, SiCl4) in dry etching conditions, adjusting gas composition, flow rates, and plasma parameters to achieve optimal etching precision and controllability for oxide semiconductor layers while maintaining process simplicity
2Ease of operation
If wet etching is used, then the process is easier to implement, but miniaturization of elements cannot be achieved due to isotropic etching characteristics
Solution Approach 1:
The patent substitutes wet etching with dry etching using chlorine-containing gases, which provides anisotropic etching characteristics essential for miniaturization. This replacement maintains operational ease through automated plasma control while enabling precise dimensional control for sub-micron element sizes
3Ease of manufacture
If wet etching with chemical solutions is used, then the process is simpler, but controllability deteriorates
Solution Approach 1:
The patent changes from liquid chemical solutions to gas-phase plasma with chlorine-containing gases, enabling precise control of etching parameters such as gas flow rate, pressure, temperature, and plasma power. This provides superior controllability while maintaining ease of manufacture through automated process control systems
4Manufacturing precision
If dry etching with chlorine-containing gases is used, then manufacturing precision and controllability improve, but the device complexity increases
Solution Approach 1:
The patent uses chlorine-containing gases (Cl2, BCl3, SiCl4) in dry etching to achieve high manufacturing precision through controlled plasma reactions. The process complexity is managed by optimizing gas composition, flow rates, and plasma parameters within established semiconductor fabrication frameworks
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 allows for the production of miniaturized transistors with improved field-effect mobility and reduced off-state current, achieving on-state current requirements for integrated circuits while maintaining high reliability and precision in semiconductor device fabrication.
Implementation Method 1
selectively removing the oxide semiconductor layer by dry etching with the use of a gas containing chlorine
Implementation Method 2
An In—Sn—Zn—O-based oxide semiconductor layer can be etched by wet etching, whereas an oxide semiconductor layer containing SnO2, In2O3, or ZnO is difficult to etch by wet etching
Data Source
AI summary
To establish a processing technique in manufacture of a semiconductor device including an In—Sn—Zn—O-based semiconductor. An In—Sn—Zn—O-based semiconductor layer is selectively etched by dry etching with the use of a gas containing chlorine such as Cl2, BCl3, SiCl4, or the like. In formation of a source electrode layer and a drain electrode layer, a conductive layer on and in contact with the In—Sn—Zn—O-based semiconductor layer can be selectively etched with little removal of the In—Sn—Zn—O-based semiconductor layer with the use of a gas containing oxygen or fluorine in addition to a gas containing chlorine.