Method for measuring thickness of film on wafer edge

Abstract

A method for measuring a film thickness of a film on an edge of a wafer, comprising: off-line detecting a film at a detection point on the wafer by a four-point probe method to obtain a real film thickness of the film at the detection point, and detecting a distance from the detection point to a center of the wafer using a length measurement, in which the detection point is located between the center of the wafer and a edge point of the wafer; detecting the film at the detection point using an eddy current transducer to obtain a detected film thickness of the film at the detection point; determining a film thickness measuring correction factor according to the real film thickness, the detected film thickness at the detection point and the distance from the detection point to the center of the wafer; and measuring the film on an edge of the wafer using the eddy current transducer to obtain a measured film thickness of the film on the edge of the wafer and correcting the measured film thickness of the film on an edge of the wafer according to the film thickness measuring correction factor to obtain a real film thickness of the film on the edge of the wafer.

Dependencies are inferred from the claim text.