Statistical Analysis of Emission Intensity for Silicon Dioxide Etching Using Optical Emission Spectroscopy Data

Optical emission spectroscopy (OES), spectral analysis of the light emitting from plasma, is probably the most widely used method for monitoring and diagnosing plasma processes. In this experiment, process parameters were varied simultaneously to examine the sensitivity of emission intensity and tool parameter modification. This enables us to utilize OES for monitoring the plasma process by not only simply selecting corresponding gas species but also integrating and interfacing OES data with tool parameters. Analyzing the modified emission spectra acquired from various etch run, we were able to identify how the process parameters affect plasma emission intensity, and the selected wavelength was interpreted as the etch rate. Through a comparison with the etch rate in the corresponding sample, this can be further utilized in virtual metrology (VM) in semiconductor manufacture.