Patent ID: 7002361
Filing Date: 2006-02-21
Classification: G01B,H01J

Abstract:
1. A system to measure a thickness of a film, which is disposed on or above a semiconductor wafer, at a plurality of locations of the film, the system comprising: an electron gun to irradiate an electron beam, having a plurality of energies, on the film, wherein the electron gun is adapted to irradiate an electron beam having a first energy and an electron beam having second energy; an electrode, coupled to the semiconductor wafer, to detect substrate currents in the wafer, wherein the electrode detects: a processor, coupled to the electrode, to determine the thickness of the film at the plurality of locations using (i) the amount of each substrate current of the first plurality of the substrate currents, (ii) the amount of each substrate current of the second plurality of substrate currents, and (iii) reference data, wherein the reference data is data which provides a correlation between a substrate current and a thickness of a film.