Semiconductor Processing Chamber Plasma Cleaning
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Solution Overview
Problem
Current cleaning methods for semiconductor processing chambers are inadequate in effectively removing polymers, particularly those generated during reactive ion etching, which can lead to contamination and process failures due to the limitations of vacuum equipment and chemical use.
Innovation Solution
A method involving the use of plasma etching with cleaning gases such as SF6+O2, NF3+O2, CF4+O2, or Cl2+O2 to form a plasma that dissolves and removes polymers from the processing chamber surfaces, allowing for targeted and efficient cleaning of different regions within the chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If vacuum equipment (turbo pump) is used to remove polymers from the processing chamber, then residual gases can be discharged, but polymers cannot be completely removed and accumulate on surfaces
Solution Approach 1:
The patent replaces the mechanical vacuum system (turbo pump) with a plasma-based chemical cleaning system. Plasma generated by RF power application creates reactive species that chemically decompose and remove polymer deposits, achieving complete removal where mechanical vacuum fails.
Solution Approach 2:
The patent changes the cleaning mechanism from physical vacuum extraction to chemical plasma reaction. By applying RF power to generate plasma and controlling gas composition, the system transforms polymer deposits into volatile products that can be completely removed, addressing the limitation of vacuum equipment.
2Quantity of substance
If chemical cleaning methods are used to remove polymers, then cleaning effectiveness improves, but the process chamber must be opened causing polymer lumps to fall onto wafers
Solution Approach 1:
The patent maintains the processing chamber in a vacuum environment throughout the cleaning process. Plasma cleaning is performed in-situ without breaking vacuum, preventing polymer lumps from falling onto wafers while achieving effective polymer removal through chemical reactions.
Solution Approach 2:
The patent uses plasma as an intermediary cleaning mechanism that operates within the sealed chamber. The plasma field enables chemical cleaning without physical chamber opening, eliminating the risk of polymer lump contamination while maintaining cleaning effectiveness.
3Manufacturing precision
If reactive ion etching is used to form fine patterns, then manufacturing precision improves, but polymer by-products are generated that accumulate and flake off as particles
Solution Approach 1:
The patent converts the harmful polymer deposits into beneficial cleaning opportunities. By applying plasma cleaning with appropriate gas composition and RF power, the accumulated polymers are chemically decomposed and removed, transforming the contamination problem into a controlled cleaning process that prevents particle generation.
Solution Approach 2:
The patent implements continuous or periodic plasma cleaning to prevent polymer accumulation. By maintaining regular cleaning cycles, the system prevents polymer buildup that would otherwise flake off as particles, ensuring continuous particle-free operation while maintaining etching precision.
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 effectively removes a wide range of polymers, including those containing SiO2, Si, F, Cl, Br, C, and Si—Br, Si—Cl, Si—F, thereby enhancing the reliability and yield of semiconductor devices by preventing polymer contamination and reducing the risk of process failures.
Implementation Method 1
providing cleaning gas including an O-based gas and at least one gas selected from the group consisting of an F-based gas and a Cl-based gas, exciting the cleaning gas to form a plasma
Implementation Method 2
A method involving the use of plasma etching with cleaning gases such as SF6+O2, NF3+O2, CF4+O2, or Cl2+O2 to form a plasma that dissolves and removes polymers from the processing chamber surfaces
Implementation Method 3
The reactive gas is adsorbed by the target layer as atoms, ions, radicals and the like. As a result, etching occurs due to the collisions between the inactive gas ions of the plasma and the target layer, and due to a chemical reaction between the atoms, ions, radicals and the target layer
Data Source
AI summary
Methods of cleaning a processing chamber of semiconductor device fabrication equipment are highly effective in removing polymers produced as a by-product of a fabrication process from surfaces in a processing chamber. The cleaning process uses a plasma etchant produced from cleaning gas including an O-based gas and at least one gas selected from the group consisting of an F-based gas and a Cl-based gas. The polymer is dissolved in-situ using the plasma etchant. Thus, frequency at which PM (preventative maintenance) of the equipment must be performed is minimized, and the method contributes to maximizing the yield and quality of the semiconductor devices.