Patent Number: 
Section: claims

1. A standard component for length measurement, comprising:a first diffraction grating; anda second diffraction grating;wherein each of components of the second diffraction grating is disposed between components of the first diffraction grating. 2. A standard component for length measurement according to claim 1, wherein the first diffraction grating comprises first components extending in a first direction and the second diffraction grating comprises second components extending in first direction. 3. The standard component for length measurement according to claim 1, wherein the first diffraction grating comprises first components having a first length and the second diffraction grating comprises second components having a second length shorter than the first length of the first components. 4. The standard component for length measurement according to claim 1, wherein in a second direction perpendicular to the first direction, first components of the first diffraction grating having a first pitch which is longer than a second pitch of second components of the second diffraction grating. 5. The standard component for length measurement according to claim 1, wherein the second diffraction grating is disposed within the first diffraction grating. 6. The standard component for length measurement according to claim 4, wherein the second pitch is not greater than 100 nm. 7. The standard component for length measurement according to claim 1, wherein the first diffraction grating and the second diffraction grating consist of one unit, and many units are arranged in a matrix. 8. A standard component for length measurement, comprising:a first region where a first diffraction grating having a first pitch is formed; anda second region where a second diffraction grating of a second pitch which is shorter than the first pitch of the first diffraction grating is formed. 9. The standard component for length measurement according to claim 8, wherein the second pitch is not greater than 100 nm. 10. An electron-beam microscopy system comprising:electron beam length measuring means for measuring processing dimensions of a sample by irradiating and scanning an electron beam;a standard component for length measurement comprising a first diffraction grating having first components and a second diffraction grating having second components, the second components being disposed between first components; andcalibrating means for calibrating a dimension based on a secondary electron signal waveform obtained by scanning the electron beam on the standard component for length measurement. 11. The electron-beam microscopy system according to claim 10, wherein the first diffraction grating comprises first components extending in a first direction and the second diffraction grating comprises second components extending the first direction. 12. The electron-beam microscopy system according to claim 10, wherein the first components of the first diffraction grating have a first length and the second components of the second diffraction grating have a second length which is shorter than the first length. 13. The electron-beam microscopy system according to claim 10, wherein in a second direction perpendicular to the first direction, the first components of the first diffraction grating have a first pitch which is longer than a second pitch of second components of the second diffraction grating. 14. The electron-beam microscopy system according to claim 10, wherein the second components of the second diffraction grating are disposed within the first components of the first diffracting grating. 15. The electron-beam microcopy system according to claim 13, wherein the second pitch is not greater than 100 nm. 16. The electron-beam microscopy system according to claim 10, wherein the first diffraction grating and the second diffraction grating consist of one unit, and many units are arranged in a matrix.