Correlation Method of Estimation of the Relief Impact Synchronicity on the CNT-needle and Probe

For nanoscale technology of measurements by the scanning microscopy systems (AFM), method is proposed to improve accuracy of estimation of the position of nanoscale needle of probe relatively roughness of relief of the investigated surface. An analysis and theoretical substantiation of the method of refinement of needle position estimation on example of using carbon nanotube (CNT) as a probe of AFM are presented. The essence of method is based on the classical technique of calculation, in real-time scanning, of the N-dimensional function of signals correlation of the measuring probe as an impact of two random processes. The first random process corresponds with changes in coordinative signals (X, Y and amplitude) of optical sensor tracking position of console (cantilever) of AFM. The second random process corresponds with changes in signal of probe, which are caused by changes in capacitance of the nanoscale “needle-surface” gap during process of needle movement when scanning studied surface. On the basis of known experimental data, a mathematical exponential model of the “needle-surface” gap is proposed. The knowing of the model is due to need prediction of “artifact” - the collision of needle with “ledge” of surface relief. The model considered in this paper takes into consideration randomness of “needle-surface” gap as an element of the system of measurement.