Ion injection monitoring method

Abstract

The invention provides a method for monitoring ion injection, which is used for preventing ion pollution during the ion injection and analyzing formation cause of polluted ions. The monitoring method comprises the following steps: 1, firstly introducing a test ion source in a reaction cavity injected with ions, and ionizing the test ion source into a plurality of different ions; 2, adopting ion beam mass spectrographic analysis to test the ions in the reaction cavity to obtain an ion beam mass spectrogram of the reaction cavity; and 3, according to the ion beam mass spectrogram obtained in step 2, removing the polluted ions and then carrying out ion injection when the spectrogram has an abnormal mass peak, or directly carrying out ion injection when the spectrogram has no abnormal mass peak. The monitoring method decides whether to directly carry out ion injection based on whether the mass peak in the ion beam mass spectrogram is abnormal, so that the monitoring method can effectively prevent pollution during the ion injection, and the abnormal mass peak in the ion beam mass spectrogram can help to analyze the formation cause of the polluted ions at the same time, so as to prevent the pollution during the ion injection.

Description

technical field [0001] The invention relates to the field of ion implantation in a semiconductor manufacturing process, in particular to a monitoring method for ion implantation to prevent contamination from ion implantation and to detect the cause of contamination to prevent ion contamination. Background technique [0002] Ion implantation is a very critical process in semiconductor manufacturing. Ion implantation includes different types of ion implantation, typically N-type ion implantation and P-type ion implantation. In the semiconductor manufacturing process, phosphorus (P) and arsenic (As) are dominant in N-type ion implantation, and boron (B) and indium (In) are dominant for P-type ions. Ion implantation is performed in a sealed reaction chamber. Most of the current reaction chambers are arc reaction chambers. During ion implantation, the ion source and the wafer with pre-implanted ions are put into the reaction chamber, and then the ions are ionized. energy, whic...

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Problems solved by technology

[0005] The purpose of the present invention is to provide a method for preventing contamination ion implantation in ion implantation, so as to solve the problem that the current ion implantation cannot detect whether the ions implanted into the wafer have other contamination ions and it is difficult to detect the cause of contamination

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