公开(公告)号：US20040233442A1

公开(公告)日：2004-11-25

申请号：US10785731

申请日：2004-02-23

Applicant: KLA-Tencor Technologies Corporation

Inventor： Walter D. Mieher ,  Ady Levy ,  Boris Golovanesky ,  Michael Friedmann ,  Ian Smith ,  Michael E. Adel ,  Christopher F. Bevis ,  Paola Dececco ,  John Fielden ,  Noah Bareket ,  Kenneth P. Gross ,  Mark Ghinovker

IPC: G01B011/00

CPC classification number: G03F9/7088 ,  G01N21/956 ,  G01N2021/213 ,  G03F7/70625 ,  G03F7/70633 ,  G03F7/70683 ,  G03F9/7049 ,  G03F9/7084

Abstract: Disclosed is a method of determining an overlay error between two layers of a multiple layer sample. For a plurality of periodic targets that each have a first structure formed from a first layer and a second structure formed from a second layer of the sample, an optical system is employed to thereby measure an optical signal from each of the periodic targets. There are predefined offsets between the first and second structures. An overlay error is determined between the first and second structures by analyzing the measured optical signals from the periodic targets using a scatterometry overlay technique based on the predefined offsets. The optical system comprises any one or more of the following apparatus: an imaging reflectometer, an imaging spectroscopic reflectometer, a polarized spectroscopic imaging reflectometer, a scanning reflectometer system, a system with two or more reflectometers capable of parallel data acquisition, a system with two or more spectroscopic reflectometers capable of parallel data acquisition, a system with two or more polarized spectroscopic reflectometers capable of parallel data acquisition, a system with two or more polarized spectroscopic reflectometers capable of serial data acquisition without moving the wafer stage or moving any optical elements or the reflectometer stage, imaging spectrometers, imaging system with wavelength filter, imaging system with long-pass wavelength filter, imaging system with short-pass wavelength filter, imaging system without wavelength filter, interferometric imaging system, imaging ellipsometer, a spectroscopic ellipsometer, a laser ellipsometer having a photoelastic modulator, an imaging spectroscopic ellipsometer, a scanning ellipsometer system, a system with two or more ellipsometers capable of parallel data acquisition, a system with two or more ellipsometers capable of serial data acquisition without moving the wafer stage or moving any optical elements or the ellipsometer stage, a Michelson interferometer, and a Mach-Zehnder interferometer, a Sagnac interferometer, a scanning angle of incidence system, a scanning azimuth angle system, a null first order differential reflectometer, a null first order differential polarized reflectometer.