Application of a GaAs/InGaP superlattice in nanometric lateral scales

The National Institute of Advanced Industrial Science and Technology (AIST), National Metrology Institute of Japan (NMIJ) developed nanometric lateral scales (design pitch: 25 nm) consisting of a GaAs/InGaP superlattice (multilayer) for atomic force microscope (AFM) and scanning electron microscope (SEM) calibration. The pitch of the fabricated nanometric lateral scales was measured using our AFM with a differential laser interferometer (DLI-AFM) and the uncertainty in the pitch measurements was evaluated. The average pitch and its expanded uncertainty (k = 2) were 25.39 nm and 0.43 nm, respectively. The quality of the developed scales was high enough to make them a suitable candidate for CRMs. On the basis of the obtained results in this technical study, the fabrication procedure and layout of the nanometric lateral scales will be optimized for the future distribution of these scales.