Plasma processing device and method for monitoring plasma technology process

Abstract

The invention discloses a plasma processing device and method for monitoring a plasma technology process. The plasma processing device comprises a plasma reaction chamber of a processing substrate anda monitoring device for monitoring a substrate processing process. The monitoring device comprises an incident light source, a spectrometer and a data processing device. The incident light source isused for emitting pulse incident light to the surface of the substrate in a reaction chamber; the spectrometer is used for collecting optical signals inside the reaction chamber; the data processing device is used for receiving the optical signals collected by the spectrometer and providing a modulation signal having a same period as a pulse incident light period; the modulation signal has a positive direction and a negative direction and products of the modulation signal and the background light signal in each period are mutually canceled each other out after superposition; a product of the pulse reflection optical signal and the modulation signal is not zero; and the data processing device uses an obtained pulse reflection optical signal to calculate a terminal of the plasma technology process.

Description

technical field [0001] The invention relates to the technical field of plasma processing, in particular to the technical field of monitoring the plasma processing process. Background technique [0002] Plasma processing technology is widely used in semiconductor manufacturing process. During the deposition or etching of semiconductor substrates, the process needs to be closely monitored to ensure that the results of the deposition process or etching process are well controlled. A commonly used etching process control method is Optical Emission Spectroscopy (OES). Atoms or molecules in a plasma are excited by electrons to an excited state and emit light of a specific wavelength as they return to another energy state. The wavelengths of light waves excited by different atoms or molecules are different, and the light intensity changes of the light waves reflect the changes in the concentration of atoms or molecules in the plasma. OES is to extract the characteristic spectral...

AI Technical Summary

Problems solved by technology

However, in the process of monitoring the spectrum, the optical signal of a specific wavelength emitted after the atoms or molecules in the plasma are excited by electrons to the excited state always exists, and the intensity is relatively large, sometimes even the intensity of the optical signal emitted by the plasma exceeds that of the incident Optical signal strength, which interferes with the reading of the reflected incident light signal making it difficult to measure the incident light signal

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