Patent ID: 8502143

Claim:
A method for measuring nanoscale deformations in a measurement area of a crystal specimen, comprising: i) providing a crystal specimen in a form of a wafer with approximately parallel faces, said crystal specimen comprising a measurement area, of which crystal deformations are to be measured, and a reference area, wherein the reference area is assumed to be without deformations and is coplanar with the measurement area; ii) illuminating one face of said specimen with a spatially coherent beam of radiation capable of being diffracted by a crystal lattice of the specimen; iii) superposing a first beam of radiation diffracted by the measurement area of the specimen with a second beam of the same radiation diffracted, to the same order, by the reference area so as to cause these two diffracted beams to interfere at an image plane; iv) measuring spatial periodicity and orientation of fringes of a resulting interference pattern; and v) deducing a difference in a lattice parameter and/or orientation between said reference area and the measurement area, said difference in lattice parameter and/or orientation being indicative of a state of deformation of the measurement area at a nanoscale.