Patent ID: 7378670
Filing Date: 2008-05-27
Classification: C23C,H01J

Abstract:
1. A method of reducing doping process impurities in an ion implantation apparatus having a chamber through which an ion beam path extends, the method comprising: providing a removable shielding assembly for the chamber comprising at least first and second removable shielding members, the at least first and second removable shielding members being made of graphite or impregnated graphite; installing the shielding assembly in the chamber such that the first shielding member covers a first magnetic area inside the chamber and the second shielding member covers a second magnetic area inside the chamber; using the ion implantation apparatus for implanting ions into semiconductor wafers; removing the shielding assembly from the chamber after the ion implantation apparatus has been used for implanting ions into semiconductor wafers for a period of time; cleaning the shielding assembly while the shielding assembly is removed from the chamber; and re-installing the shielding assembly in the chamber for further use of the ion implantation apparatus.