Key Engineering Materials Vol. 613

Abstract: The objective of this research is to develop a PC-based closed-loop nanopositioning system using the dual-frame two-axis drive single mobile independent framework. The stage body was supported by an air bearing on a granite base to reduce the frictional force. The developed stage was driven by the PC-Based interface of ANCA 5DX CNC controller, for the precision motion control of the linear motors. The laser scales were used as the feedback sensors so that the closed loop control of the developed system was possible. Based on the test results, the designed closed loop nanopositioning system was capable of precision positioning within the travel of 100 mm along X-axis and Y-axis. The Z-direction stage stability of the developed system was 20 nm, the maximum yaw error of the stage moving along X-axis was about 3.77 arc-seconds, and the maximum pitch error of the stage moving along Y-axis was about 1.04 arc-seconds, based on the test results. By utilizing the PC-Based interface of ANCA 5DX CNC controller based closed-loop PID control system, the positioning capability of X-axis and Y-axis was about 20 nm. Performing the circular test with radius of 20 mm, the deviation of circular positioning test was about 223 nm. Based on the tracing speed test results, the standard deviation along X-axis and Y-axis was 5 nm under tracing speed of 0.05 mm/min.

Abstract: Upcoming Semiconductor Technology Nodes will still be based on optical lithography by ArF water immersion technology because there are still too many open issues preventing extreme ultraviolet (EUV) lithography from being introduced into production. Several kinds of multi- patterning technology are in use to overcome the optical resolution limitation of 193nm high NA illumination and still to achieve <32nm half-pitch. Mask registration metrology must be adapted to provide useful and comprehensive data on the mask contribution to wafer overlay

Abstract: Leading edge lithography processes require silicon wafers of nearly perfect flatness. In order to improve wafer manufacturing processes as well as the wafer quality, already early manufacturing processes like grinding and lapping have to be monitored. Assessment of nanotopography (NT) is an established approach to analyze surface features in a spatial wavelength range of 0.2 to 20 mm on silicon wafers end of line. This paper presents a fully automated measurement tool to measure NT on wafers with low reflectivity and wafer sizes up to 300 mm, based on the FRT MicroProf^® MFE series. The system features a newly developed white-light interferometry sensor with a field of view of approximately 85 x 85 mm². 16 single measurements are stitched to cover the entire surface of a 300 mm wafer. An NT analysis optimized stitching algorithm was developed in order to combine the individual images to a complete wafer map. The stitched map of the non-polished wafer is subsequently high-pass filtered and analyzed to quantify NT. Measurement system analysis studies provided repeatability values below 1 nm at a throughput of > 20 wafer/h.

Abstract: In current production metrology contour and roughness of work pieces has to be controlled in demanding small tolerances. It is important that the results not only have to be accurate, but also the measurement has to be performed effective and fast. It would be convenient to have the possibility measuring first a continuous surface profile and than performing different evaluations on adjacent segments. We describe a measurement system which is based on a tactile probe with a diamond tip. The position of each axis is measured by high resolution and high accuracy digital scales. The instrument is calibrated and traced back by only using one precision sphere covering approximately the whole measuring range of 24 mm. It is shown that with only that macroscopic calibration and adjustment the accuracy for roughness measurement in all arbitrary vertical positions is reached in the nm-range. The calibration and adjustment process is described and we show the verification of the accuracy by measuring several surface specimens. The results are compared to a Physikalisch-Technische Bundesanstalt (PTB) calibration certificates for those surface roughness standards.

Abstract: To assure the metrological traceability of a measurement, it is required to perform an analysis of the measurement uncertainty specific to the measurement task. An approach to estimate the measurement uncertainty for complex systems is the so-called virtual measuring instrument: The measuring process is simulated taking into account its influencing parameters and a statistical analysis is performed by means of Monte-Carlo calculations. We present the development of such a virtual measuring instrument for scanning electron microscopy (SEM) which allows to estimate the measurement uncertainty in compliance with GUM for dimensional measuring tasks in nano- and microsystems technology. By application of this virtual instrument, model based corrections of systematic errors are made possible and the cognition of the strength of different perturbing influences can lead to recommendations to optimize measurement instruments and methods. The virtual model programmed in MATLAB is called ‘vREM’, it includes all essential components of the measuring chain of an SEM as modules: The electron source, the electron-optical lens-system, the scan-generator, the interaction of the electrons within the object, electron detectors, simple analysis procedures and consideration of external disturbances. By adjusting parameters uncertainty contributions can be assigned to the virtual probe, the virtual specimen and the virtual detector signals.

Abstract: As general methods can no longer be used to measure super-large gears, their manufacturing accuracy, performance and quality cant be guaranteed. In this paper, after introducing the characteristics, measuring requirement and the state of arts of inspection of super-large gears, a laser tracker and CMM based measuring technology, proposed by Shi, was presented, and the key techniques were discussed. By taking full advantage of the characteristics of a laser tracker and a coordinate measuring apparatus, the super-large gears positioning problem, which was to determine the relationship between the instrument and workpeice, was solved. Thus, the gears profile, helix, and topology error etc. could be measured. Experiments have been carried out to verify the effectiveness of the method. The results showed that the proposed method could be used to measure super-large gears with the diameters up to 10m.

Abstract: The measurement of a part on a coordinate measuring machine may be affected by many factors such as machine frame accuracy, probe configuration, measuring environment, and measurement strategy. In order to understand the effect of some of those factors on measurements performed in industrial-grade machines, a master production workpiece has been chosen and circulated in Brazilian industries for collecting data points of the calibrated workpiece features according to a predefined master measuring protocol. Conclusions could be drawn about the behavior of each machine under varying conditions, measurement divergences from similar machines operating under distinct conditions, the complexity of measurements with CMMs, and the need for good measurement practices in the productive sector.

Abstract: Deteriorate of prosthesis can be defined as the mechanical wear of the components moving on each other. It occur the change of the rise and the shape of the component. This load can be depend on the extent of the load, the material of the component, the thickness of the polyethylene layer, the smoothness of the machining, the hardness of the surface of the head component and also on the implantation method. A 26-28 mm head diameter can be optimal and the upper level of the allowable polyethylene wear per year is 0.1 mm. It is not easy to determinate the usability of the different types [.

Abstract: The temperature has a critical effect on long gauge block measurement by interferometry. To reduce this effect, we developed a vacuum insulated wall for long gauge block measurement system. The long gauge block chamber has the dimension of 1.2 m x 2 m. The vacuum insulating walls are mainly composed of 8-mm and 10-mm thick Aluminum plates as the chamber walls and a rotary pump. Using this technique, the vacuum insulator is treated to have the pressure of 0.9 mbar. This technique can reduce heat transfer from outside environment to the chamber due to low heat conductivity of the system. The temperature stability of the chamber had been continuously investigated using 5 Pt100 probes and their temperature stability are below 15 mK at 17 ^OC, 20 ^OC and 23 ^OC

Abstract: In industrial metrology, the system of fringe projection for the fast determination of 3D surface data has been established. The combination of areal and structured projection with two-dimensional optical sensors and triangulation measurement principle allows very high measurement point densities with reasonable accuracy. There are great difficulties with high gloss surfaces and with very dark surfaces for state of the art systems. Transparent materials cannot be measured using the visible spectrum of light. We have therefore developed a new structured light projection system that solves these problems. For the first time the physical principle of energy conversion is utilized in areal structured light projection. We are presenting first results to show the advantages and the capability of this new measurement principle.