System and method for monitoring semiconductor processing technique

Abstract

The invention provides a monitoring system for semiconductor processing technology, which consists of: a continuum light source, an intermittent mechanism, an optical circuit controller, an optical alignment device, a spectrometer, a data processing unit and an algorithm unit; the continuum light source enters the semiconductor processing cavity through the intermittent mechanism, the optical circuit controller controls the intermittent mechanism to convert continuous incident light into pulsed light and controls the spectrometer to collect the spectrum signals sent from the semiconductor processing cavity. The data processing unit and the algorithm unit are used for processing the data and confirm end point of the technology; and simultaneously, the invention provides a monitoring method for semiconductor processing technology. In the monitoring system and the method for semiconductor processing technology disclosed by the invention, the interference spectrum signals are not easy to be interfered by the plasma emission spectrum and the fluctuation thereof, thus remarkably improving the signal to noise ratio and the resolution ratio. Additionally, the accurate control to the stability and the service life of the light source is realized by carrying out the real-time monitoring for the intensity and the service life of the light source, thereby greatly improving the accuracy and reliability of the technology monitoring.

Description

technical field [0001] The invention relates to the technical field of semiconductor manufacturing, in particular to a monitoring system and method for a semiconductor processing technology. Background technique [0002] Semiconductor processing is the key process of integrated circuit manufacturing. For example, plasma etching is one of the commonly used semiconductor processing technologies. The principle is that the etched substance reacts with the active groups in the plasma, and the reaction products are separated from the substrate surface. The cavity is evacuated by a vacuum system, thereby removing a specific layer or a specific portion of a layer. Its purpose is to completely copy the mask pattern to the surface of the silicon wafer, covering the control of the size of the front-end CMOS gate and the etching of the back-end metal. The quality of the etching directly affects the integrity, resolution and accuracy of the pattern. . [0003] In the process of semicon...

AI Technical Summary

Problems solved by technology

Although the existing technology can monitor the film thickness in situ and determine the end point of the process, this method essentially uses a pulsed light source to realize the periodic and alternate acquisition of OES and IEP signals until the end of the process. However, the intensity stability of the pulsed light source is not high. Generally speaking, the OES signal depends on the plasma emission spectrum itself. The sensitive wavelength in the emission spectrum is monitored by the spectrometer and the change trend of the wavelength is analyzed to determine the process end point. However, due to the in-situ monitoring during the etching process, the IEP signal will inevitably be Affected by the plasma emission spectrum, the pulsed light source with unstable intensity is more likely to be interfered by the plasma emission spectrum and its fluctuations, resulting in a low signal-to-noise ratio; in addition, the fluctuation of the pulsed light source will also lead to fluctuations in the intensity of incident light and reflected light , resulting in poor interference signal resolution, affecting the accuracy and reliability of process monitoring

Images