PLASMA ETCHING APPARATUS CAPABLE OF IN-SITU MONITORING, ITS IN-SITU MONITORING METHOD AND IN-SITU CLEANING METHOD FOR REMOVING RESIDUES IN PLASMA ETCHING CHAMBER

摘要

PURPOSE: A plasma etching device, its in-situ monitoring method and the in-situ cleaning method are provided to optimize the process recipe for performing the polysilicon plasma etching process by using a residual gas analyzer - quadrupole mass spectrometer and cleaning the etching chamber by in-situ after the etching step. CONSTITUTION: From a sampling manifold, the gas in the etching chamber is sampled. In order to decrease the initial grounding value of the gas analyzer below a predetermined level, the gas is baked and outgassed. With respect to the semiconductor wafer received in the etching chamber, the etching process for forming a polysilicon storage electrode is performed to monitor the react mechanism of the process gas. After the etching process is completed, the wafer is unloaded and the waste gas in the etching chamber is discharged. As the cleaning gas is supplied into the etching chamber with in-situ, the reaction mechanism of the cleaning gas is monitored. In addition, in order to perform the residual cleaning step, the semiconductor wafer is unloaded in the etching chamber. SF6 + Cl2 gas is supplied to the etching chamber to clean the etching residuals in the etching chamber. The residuals cleaned is pumped to be removed.