DETECTOR FOR ELECTROSTATIC CHARGE AMOUNT ON WAFER IN ION IMPLANTING DEVICE

摘要

PURPOSE:To enable an accurate measurement of an amount of electrostatic charge by a method wherein a conductive piece is provided on a side face of an irradiated face of a water disk, an electrostatic induction piece electrically connected with the conductive piece is provided on the rear of the wafer disk through the intermediary of an insulator, and a static electricity sensing element is provided on the fixed section near to the electrostatic induction piece so as to face it. CONSTITUTION:A conductive piece 6 is provided to a side face of an irradiated face of a wafer disk 4 through the intermediary of an insulator 13, and an electrostatic induction piece 7 electrically connected with the conductive piece is provided on the rear of the wafer disk 4 through the intermediary of an insulator 15. A static electricity sensing element 9 is provided to a fixed section 3 near to the electrostatic induction piece 7 so as to face toward it. The static electricity sensing element 9 is provided with a conductive enclosure 16 which is grounded to a disk chamber cover 3 so as to protect the sensing element 9 against an external turbulence. The static electricity sensing element 9 is connected, for instance, to an ammeter to detect a charging state of the conductive piece 6 based on the change of a current value. By these processes, an amount of an electrostatic charge on a wafer can be accurately measured by a simple means without extracting a noise generated at a detected part as a signal.