In addition to other development activities in the field of SPM metrology, two commercial SFMs have been extended in the past two years by miniaturized homodyne laser interferometers. The positioning system of a third device developed into a large range SFM at PTB, has already been equipped with laser interferometers by the manufacturer. These laser interferometers were developed in cooperation with the Technical University IImenau and SIOS Messtechnik GmbH. In the case of all devices, special attention was already paid in the construction of the interferometer extension and the instrument design to the fact that principles as minimization of Abbe errors and tilting were complied with. At PTB, the SFMs described serve for the calibration of standards and the general characterization of microstructures. In the following, the SFMs equipped with laser interferometers will be referred to as metrological SFMs.

Examples :