The rapid development of devices of microsystem equipment (MST), observable recently, has undoubted advantages of these devices (miniature, high functionality, manufacturability, reliability, low power consumption, etc.). However, high requirements to the geometric and mechanical characteristics of MST devices in their manufacture and operation require the use of highly effective and rapid control methods, among which the atomic-force microscopy (AFM) method is promising.
At the same time, despite the advantages of the AFM method, its practical application in checkup the geometry and mechanical characteristics of materials is limited to a number of problems that have not been solved so far: the lack of data on the physical regularities of the influence of external conditions and control regimes on the metrological characteristics of the AFM method; insufficient comprehension of the processes of force and energy interaction of AFM probes with surfaces; lack of tools for all-inclusive research and so on.
Therefore, the dissertation is devoted to solving an important scientific and technical problem improvement of existing and creation of new methods and means of atomic-force microscopy for non-destructive testing of the geometric and mechanical characteristics of the components of the microsystem technology through the use of automated systems for measuring and controlling these characteristics with regard to the action of destabilizing factors, development of mathematical and experimental statistical models, which generally represents the scientific basis for managing the quality of the monitoring process based on the atomic force microscopy method and is of practical importance for the microsystem and optical-electromechanical instrument-making industries with their subsequent introduction into production.
To solve the problem of dissertational research, scientifically based methodology has been created to improve the methods and means of atomic force microscopy for non-destructive testing of the geometric and mechanical characteristics of the components of microsystem engineering through the development of mathematical and experimental statistical models, the use of methodological, technical and software tools to automate the process of controlling these characteristics allows to improve the accuracy, increase the sensitivity and reproducibility of the results of the control, taking into account the actions of destabilizing factors.
Refined physical and mathematical models of the force and energy interaction of AFM probes with material surfaces minimized the limiting factors (capillary forces, electrostatic interaction forces, heat dissipation in the zone of the probe's physical contact with the surface). This reduced the relative error of measurement by 8 to 11%, increased the sensitivity of the method by 17 to 19%, and the convergence of the results of the study in 2,1 – 2,4 times. The range of scanning operating parameters (speed (18 – 26) nm / s, mechanical relaxation time (4,8 – 6).10-3 s, step (78 – 82 nm) was also determined, which ensures stable operation of the AFM during the measurement.
New experimental statistical models were proposed in the paper. This made it possible to estimate the influence of climatic factors (temperature, relative humidity, ammonia content, corrosion active sulfur compounds) on high accuracy (the discrepancy between the calculated and experimental data during ten parallel experiments does not exceed 4,8%) on metrological characteristics of the AFM method. The results obtained in the model allowed to increase the period of reliable operation of the probe by 30 – 40% and to reduce the rate of erosion of its surface by 1,2 – 3,4 times.
A new method has been developed to improve the accuracy, sensitivity and reproducibility of the process of non-destructive testing of the geometric and mechanical characteristics of components of microsystem engineering based on the developed tool and software and hardware for automating the monitoring, taking into account the effect of destabilizing factors, the use of which allows:
– to measure and control the characteristics of the objects of study with an error
of 2,7 – 5,4% and the probability of failure-free operation of the probes 0,95 – 0,98 by using probes from atomic force microscopes and test objects modified using electron-beam micromachining;
– control the operating parameters in the control process by applying laser beam positioning systems to an atomic force microscope probe and removing residual triboelectric charge;
– expand the boundaries of the investigated surface area (in the vertical plane
1,5 – 2,25 times) and increase its detailing 1,6 – 2,1 times.
The results of the research were tested and found practical application in domestic and foreign enterprises (confirmed by the acts of implementation), and also used in the educational process of institutions of higher education in Ukraine.
