Rapid progress in several high-tech industries has significantly increased the need for dimensional micro- and nano-metrology. Structures to be measured are becoming more complex with smaller structure widths and higher aspect ratios in increasingly larger surface regions and potentially highly curved surfaces. Significant international effort can be seen to develop high-capacity measuring machines with nanometre precision in growing measuring ranges up to hundreds of millimetres. This paper begins with an outline of the requirements stemming from high-tech developments currently being done or expected in the future and discusses recent developments in the field of nanopositioning and nanomeasuring technology with respect to basic measurement approaches, laser interferometer systems. The large range of nanoprobe systems usable in nanomeasuring machines is discussed, such as optical focus sensors, white light interferometer microscopes, CCD camera microscopes using the depth from the focus method, tactile stylus probes, atomic force microscopes (AFMs) and 3D microprobes. The versatile properties of these sensors allow the machine to be used in many different metrological applications. The paper also introduces a multi-sensor approach using a microscope revolver. It concludes with an illustration of metrologically challenging measurements, e.g., scanning micro-structures of curved optical surfaces or performing AFM scans of very large regions with significant data volume.

With the nanopositioning and nanomeasuring machine (NPM-Machine) developed at the Technische Universität Ilmenau, subnanometre resolution and nanometre uncertainty in a measuring volume of 25 × 25 × 5 mm3 have been demonstrated in the last few years. This machine allows the most various measuring problems to be solved. In practice, however, there are too many different requirements for sensing surfaces or for detecting structures. So, this paper deals with the development and also the improvement of several optical and tactile probes for application in the NPM-Machine. A focus probe with a spot size of approximately 0.5 µm, a working distance of 1.5 mm and a resolution of less than 1 nm was developed and adopted in the NPM-Machine. In the next step, the working distance was improved to exploit the full vertical range of the NPM-Machine of 5 mm. To realize tactile sensing, an atomic force probe and tactile stylus probe were developed on the basis of the focus probe. These probing systems can acquire measuring data only by scanning the surface sequentially and point-by-point. To increase data acquisition, we realized a sensor based on a white-light interference microscope and parallel sampling of 1600 × 1200 data points. First results of fringe evaluation with laser interferometer reference are presented.

The conception and properties will be introduced of an interferometer that exclusively uses plane mirrors as reflectors; thus, these interferometers correspond well to the original Michelson interferometer. First, the relationship between the interference conditions and the detection with photodiodes will be discussed using the example of known interferometers as well as reasons given for primarily using corner cube reflectors in these devices. Next, the conceptual design of the plane mirror interferometer will be presented. This type of interferometer possesses new properties which are significant for metrological and technical applications. Only one measuring beam exists between the polarizing beam splitter and the measuring mirror and this beam alone represents the Abbe axis. This property allows the significant reduction of the Abbe error. The interferometer is able to tolerate tilting on the order of about 1′. This ensures the orthogonality between the measuring beam and the measuring mirror during the measurement. This property can be used in three-dimensional measurements to erect the three measuring beams as a x–y–z Cartesian coordinate system on the basis of three orthogonal mirrors. The plane-mirror interferometer also allows non-contact measurements of planar and curved surfaces, e.g. silicon wafers.

The Nanopositioning and Nanomeasuring Machine NMM-1 was designed for measurements within a measuring volume of 25 mm by 25 mm by 5 mm. The interferometric length measuring and drive systems make it possible to move the stage and corner mirror with a resolution of 0.1 nm in all three axes. The object being measured is placed on the corner mirror and can be measured with different probe systems. The very high precision of the machine can be attributed to several factors, the accuracy of the interferometric measuring systems, the three-dimensional realization of the Abbe comparator principle, the precise reference coordinate system defined by the corner mirror and the additional compensation of angular deviations. This article describes a small part of the measurement uncertainty analysis for a displacement measurement using two positions of the measuring mirror. In particular this article discusses the influence of offset, amplitude and phase deviations in the interference signals.

High-precision metrology has emerged as an enabling technology for modern key technologies. Therefore, at the Technische Universität Ilmenau, a new nanopositioning and nanomeasuring machine NPMM-200 with a measuring range of 200 mm × 200 mm × 25 mm, and a resolution of 0.02 nm was developed. The machine represents the great improvement of the extended threedimensional Abbe comparator principle to achieve nanometre accuracy. All six degrees of freedom of the mirror plate with the measuring object are measured by fibre-coupled laser interferometers, the signals of which are then used together with the probe system signals for a high-precision position and orientation control and surface and coordinate measurements. This paper presents the metrological concept, the realized design as well as the metrological parameters.