Varian Semiconductor Equipment Associates, Inc.

Nathan Roth

Mark R Amato

David R Timberlake

A defining aperture plate having at least two differently sized apertures is used in conjunction with at least two charge collectors. Because of the difference in aperture width, the two charge collectors receive different amounts of ions, where the amount is proportional to the associated aperture width. By monitoring the ratio of the charge collected by the first charge collector to the charge collected by the second collector, the amount of erosion can be monitored and optionally compensated for.

Growing community of inventors

Peabody, MA, United States of America

Nathan Roth