A substrate is provided with device structures and metrology structures (800). The device structures include materials exhibiting inelastic scattering of excitation radiation of one or more wavelengths. The device structures include structures small enough in one or more dimensions that the characteristics of the inelastic scattering are influenced significantly by quantum confinement. The metrology structures (800) include device-like structures (800b) similar in composition and dimensions to the device features, and calibration structures (800a). The calibration structures are similar to the device features in composition but different in at least one dimension. Using an inspection apparatus and method implementing Raman spectroscopy, the dimensions of the device-like structures can be measured by comparing spectral features of radiation scattered inelastically from the device-like structure and the calibration structure.