Microwave Plasma Device Coaxial Electrode Design
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Solution Overview
Problem
Current semiconductor production methods face challenges in producing flawless dielectric layers, especially at low temperatures, due to issues like contamination, particle inclusions, and high thermal budgets, which affect the reliability and performance of semiconductor components.
Innovation Solution
A microwave plasma device with a coaxial electrode design generates a high-density plasma of low-energy ions and electrons, allowing for the formation of thick, homogeneous dielectric layers on semiconductor substrates at temperatures below 800°C, independent of substrate temperature and doping species.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermal oxidation is used to produce dielectric layers, then the layers can be formed on semiconductor substrates, but the process requires high temperatures leading to high thermal budget and potential substrate damage
Solution Approach 1:
The patent changes the fundamental parameter of oxidation mechanism from thermal diffusion-controlled oxidation to plasma-enhanced oxidation. This allows the process to proceed at lower temperatures (reducing thermal budget) while maintaining oxidation effectiveness through plasma activation, thus preventing substrate damage while forming quality dielectric layers
Solution Approach 2:
The patent replaces the thermal field (heat-driven oxidation) with a plasma field (ion/electron-driven oxidation). This substitution eliminates the need for high temperatures, allowing dielectric layer formation at reduced thermal budgets that prevent substrate damage and maintain reliability
2Temperature
If CVD or ALD processes are used to deposit dielectric layers, then layers can be formed at lower temperatures, but particle inclusions and nucleation problems cause electrical flaws
Solution Approach 1:
The patent changes the deposition mechanism from chemical vapor transport (CVD) or atomic layer deposition (ALD) to direct plasma oxidation. This parameter change eliminates the nucleation and particle inclusion problems inherent in CVD/ALD processes, producing flaw-free dielectric layers with superior electrical properties while maintaining low temperature processing
Solution Approach 2:
The patent uses plasma as a strong oxidizing environment that directly converts silicon to silicon oxide without the intermediate steps of CVD/ALD. This accelerated oxidation process through plasma avoids particle contamination and nucleation defects, achieving both low temperature processing and high layer quality
3Productivity
If high power microwave plasma is used to increase plasma density, then oxidation rate increases, but substrate temperature increases beyond desired limits
Solution Approach 1:
The patent applies local quality by creating a non-uniform microwave field distribution that concentrates plasma generation at the substrate surface interface rather than heating the bulk substrate. The electromagnetic field is configured to maximize plasma density at the oxidation front while minimizing thermal conduction into the substrate, enabling high oxidation rates with controlled substrate temperature
Solution Approach 2:
The patent transitions from thermal field control to electromagnetic field control for plasma generation. By using microwave frequency electromagnetic fields, the system can independently control plasma density (through field strength and frequency) separate from substrate temperature, allowing high oxidation rates without proportional temperature increase
4Quantity of substance
If conventional plasma sources are used, then plasma can be generated, but the plasma density is insufficient for efficient dielectric layer production
Solution Approach 1:
The patent introduces a resonant cavity as an intermediary structure that couples microwave energy to the plasma medium. This resonant cavity acts as a mediator that concentrates electromagnetic energy into the plasma, dramatically increasing plasma density and enabling efficient dielectric layer formation through enhanced plasma chemistry
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 enables the production of flawless dielectric layers with improved reliability and reduced thermal stress, enabling the fabrication of high-quality semiconductor components with enhanced electrical properties and increased substrate compatibility, including silicon nitride oxidation at room temperature.
Implementation Method 1
A microwave plasma device with a coaxial electrode design generates a high-density plasma of low-energy ions and electrons
Implementation Method 2
The at least one electrode is surrounded by a nonconductive material at least along the region, in which the coaxial outer conductor is open along the longitudinal axis of the inner conductor
Implementation Method 3
The method enables the production of flawless dielectric layers with improved reliability and reduced thermal stress, enabling the fabrication of high-quality semiconductor components with enhanced electrical properties and increased substrate compatibility, including silicon nitride oxidation at room temperature
Data Source
AI summary
A device for producing a microwave plasma, and a device and a method for treating semiconductor substrates with a microwave plasma, the microwave plasma device comprising at least one electrode (21, 22, 23), an electrode (21, 22, 23) comprising a coaxial inner conductor (21) made of electrically conductive material and a coaxial outer conductor (22) made of electrically conductive material and surrounding the inner conductor at least partially and being disposed at a distance thereto, and a plasma ignition device (23) that is connected to the coaxial inner conductor (21), characterized in that the coaxial outer conductor (22) comprises at least one first partial region (31) in which it completely surrounds the coaxial inner conductor (21) along the longitudinal axis thereof and comprises at least one further partial region (32) in which it surrounds the coaxial inner conductor (21) partially such that microwave radiation generated by the microwave generator (20) can exit in the at least one further partial region (32) substantially perpendicular to the longitudinal axis of the coaxial inner conductor (21).