Fluorine Radical Sensing for Remote Plasma Process Control
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Solution Overview
Problem
Current technologies face challenges in effectively measuring, filtering, and recycling gases used in semiconductor processing, such as NF3 and F2, which pose environmental hazards and cause excessive wear on equipment.
Innovation Solution
A system incorporating a remote plasma source, a processing chamber with a radical sensor, and a controller that adjusts settings based on measured fluorine radical concentrations, along with a recirculation line and filter to recycle and filter gases, is introduced.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If radical species are used for etching or chamber cleaning processes, then process effectiveness is improved, but chamber surface wear increases and recombination losses occur
Solution Approach 1:
The system segments the plasma generation function from the processing chamber by using a remote plasma source. This separates radical generation from the chamber environment, allowing radicals to be delivered without excessive recombination on chamber surfaces while maintaining process effectiveness.
Solution Approach 2:
The patent introduces an intermediary transport system (plasma delivery mechanism) that carries radical species from the remote source to the chamber. This intermediary protects radicals from premature recombination by controlling their path and exposure to chamber surfaces.
2Object-affected harmful factors
If chamber cleaning is conducted frequently to prevent processing gases from exposing to equipment surfaces, then equipment wear is reduced, but operation time is lost
Solution Approach 1:
The patent extracts the chamber cleaning function from the regular process cycle by using a remote plasma source that can deliver controlled radical doses. This allows cleaning to be performed more efficiently without requiring extended downtime, as radicals can be delivered precisely when needed without continuous exposure.
Solution Approach 2:
The system changes the parameter of radical delivery from continuous exposure to controlled, time-limited doses. By adjusting the timing and duration of radical delivery, the system achieves cleaning effectiveness while minimizing the time chambers are taken offline for maintenance.
3Productivity
If fluorine containing gases are used to generate radicals, then radical species are produced for processing, but environmental hazards and gas waste increase
Solution Approach 1:
The system implements feedback control by monitoring radical concentrations and adjusting plasma source parameters accordingly. This ensures optimal radical generation efficiency, reducing excess gas consumption and minimizing environmental hazards from unreacted or wasted fluorine-containing gases.
Solution Approach 2:
The patent changes the operational parameters of plasma generation to optimize radical yield while minimizing gas consumption. By adjusting plasma power, gas flow rates, and residence time, the system achieves high radical generation efficiency with reduced environmental impact.
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 system improves throughput, reduces waste of input gases, and minimizes environmental impact by accurately measuring and controlling radical species concentrations, and by recycling valuable gases like F2 and Ar.
Implementation Method 1
One process to generate radical species is to use a plasma. For example, a fluorine containing gas is flowed into the chamber, and the plasma breaks the compound into elemental fluorine.
Data Source
AI summary
A system includes a remote plasma source, a processing chamber comprising a radical sensor, and a controller. The radical sensor is configured to measure the concentration of fluorine radicals in the processing chamber. The controller is to adjust one or more settings of at least one of the remote plasma source or the processing chamber based on the measured concentration of fluorine radicals in the processing chamber.