Plasma and Vacuum Processing Analysis  Solutions 

Photo From Solvay

Light emissions from semiconductor processes can be used to monitor the quality 
the process as well as to determine the endpoint of an etch process or endpoint of
​a clean cycle. 

Both the Actual Process Plasma and its Effluent Can be Monitored

Downstream Process Gas Monitoring and Endpoint

Thru the Window Process Monitoring and Endpoint
 Lightwind is pleased to offer different technology solutions for both plasma and or  gas processing.  Thru window spectroscopy depends on the light emitted during the process. Typically spectra include both atomic and molecular emissions, in a common useful range of 200 to 900 nm.  
Thru window spectroscopy  is the traditional approach that has been implemented on many process chambers. For processes with very weak signal strength (either a very small surface is etched or the etch rate is very slow) we are able to "tune" the spectrometers for specific applications.  Signal improvements of > 5 times are possible with "application specific" spectrometers.
Downstream spectroscopy is a different approach than thru the window.  In a downstream mode a small separate plasma source is used to ionize the process effluent. That ionized gas (plasma) is then analyzed in a way similar to thru the window spectroscopy.  There are many benefits to this approach:
  • Plasma intensity is  separately controlled
  • Emission does not require   an active process.. i.e. just the flow of unprocessed gas can be analyzed
  • Downstream spectroscopy can be used on processes that would otherwise be dark to thru  the window techniques
Both implementations can provide useful process information however thru the window require a window in the process chamber, and only works when the process of interest emits sufficient light.

Spectral Reference Lines
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