Ion implantation apparatus and method of determining state of ion implantation apparatus

摘要

An ion implantation apparatus according to an embodiment includes an ion implantation unit, a position detection unit, a charge supply unit, a current value detection unit, and a determination unit. The ion implantation unit scans the surface of a substrate with an ion beam containing positively charged ions and implants the ions into the substrate. The position detection unit detects the scan position of the ion beam on the substrate. The charge supply unit generates a plasma, emits electrons contained in the plasma, and supplies the electrons to the substrate. The current value detection unit detects a current value that changes in accordance with the amount of electrons emitted by the charge supply unit. The determination unit determines the charge build-up state of the substrate based on a change in the current value, the change being accompanied by a change in the scan position.

主权项

1. An ion implantation apparatus comprising:
an ion implantation unit that scans in a reciprocating manner between one end and another end of a surface of a substrate with an ion beam containing first conductive ions and implants the ions into the substrate; a position detection unit that detects a scan position of the ion beam on the substrate; a charge supply unit that generates a plasma, emits second conductive charges contained in the plasma, and supplies the charges to the substrate; a current value detection unit that detects a current value changing in accordance with an amount of the charges emitted by the charge supply unit; and a determination unit that determines a charge build-up state of the substrate based on a change in the current value detected by the current value detection unit, the change being accompanied by a change in the scan position detected by the position detection unit, wherein the determination unit:
calculates a reference straight line linking the current value detected when the scan position is located at the one end of the substrate and the current value detected when the scan position is located at the another end of the substrate; anddetermines whether the charges are normally discharged from the charge supply unit on the basis of a ratio between a total area of regions that are convex upward with respect to the reference straight line and a total area of regions that are convex downward with reference to the reference straight line, on a curve indicating changes in the current value accompanied by changes in the scan position.