Method for improving metal contamination of wafer high-energy ion implanter

Abstract

The invention puts forward a wafer high energy ion implantation machine metal pollution alleviating method comprising the following steps: after exchanging electrons with a magnesium furnace, ions generated by an ion source are turned into negative ions; after acceleration, the negative ions exchange electrons with gas and are turned back into positive ions; after acceleration, and a beam which satisfies injected energy requirements can be screened out from the positive ions via an energy screening electromagnetic field; besides the energy screening electromagnetic field, an electric field which is deviated from a direction perpendicular to the beam by a certain angle is added so as to eliminate metal pollution. According to the wafer high energy ion implantation machine metal pollution alleviating method put forward in the invention, besides the energy screening electromagnetic field, the electric field which is deviated from the direction perpendicular to the beam by the certain angle is added so as to eliminate metal pollution so as to screen out the beam of a needed energy source, injection such as metal and the like that cannot satisfy energy requirements is eliminated, and therefore metal pollution can be lowered.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, and in particular to a method for improving metal contamination of a wafer high-energy ion implanter. Background technique [0002] Ion implanter is the key equipment in the pre-process of integrated circuit manufacturing. Ion implantation is a technique for doping the area near the surface of the semiconductor. The purpose is to change the carrier concentration and conductivity type of the semiconductor. Compared with the conventional thermal doping process, ion implantation can precisely control the implantation dose, implantation angle, implantation depth, lateral diffusion, etc., overcome the limitations of conventional processes, and improve the circuit integration, turn-on speed, yield and life, reducing cost and power consumption. Ion implanters are widely used in the doping process, which can meet the requirements of shallow junction, low temperature and prec...

AI Technical Summary

Problems solved by technology

Because the separation radius of the electromagnetic field is related to the atomic mass and charge of the beam, metal ions may be implanted into the wafer with the same beam radius as the target implantation energy ion after acceleration, causing metal contamination.

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