A. S. Kolomiytsev

Formation of nanosize structures on a silicon substrate by method of focused ion beams

The results of experimental studies of modes in which nanosize structures are formed on a silicon substrate by method of focused ion beams are presented. Dependences of the diameter and depth of the nanosize structures on the ion beam current and time of exposure to the ion beam at a point are obtained. It is demonstrated that the main factor determining the rate of ion-beam milling is the ion beam current. The results of the study can be used in the development of technological processes for the fabrication of components for nanoelectronics and nanosystems engineering.

Development of New Metamaterials for Advanced Element Base of Micro- and Nanoelectronics, and Microsystem Devices

The results of experimental researches of the geometrical parameters of vertically aligned carbon nanotubes (VACNTs) are present by atomic force microscopy. The analysis of the applicability of the different AFM modes to determine the geometrical parameters of VACNTs array was carried out and based on this analysis the rapid-technique for determination of the length of the nanotubes in VACNTs array was developed. Unified two-layer polysilicon surface micromachining process for manufacture of biaxial micromechanical gyroscope , triaxial micromechanical accelerometer and biaxial nanomechanical accelerometer was proposed. Polysilicon inertial masses were fabricated by optical lithography, dry etching under different masks and wet etching of sacrificial layer. We developed AFM-technique for determination of electrical parameters GaAs nanowires (NWs) , which does not require additional operations of NW fixation and allows one to estimate the resistivity and conductivity type of NW material. The obtained results can use to develop of the nanodiagnostic methods and the processes of formation of micro- and nanoelectronic elements based.

Fabrication of advanced probes for atomic force microscopy using focused ion beam

Abstract In this work the results of experimental studies of a fabrication of advanced probes for Atomic Force Microscopy (AFM) using Focused Ion Beam (FIB) and nanolithography are reported. Ability to restore the functionality of broken AFM probe tips is shown. The superior performance of FIB-fabricated probes by observing AFM images of the nanostructures is demonstrated. It is shown that the formation of multiprobe AFM cantilevers by FIB-induced deposition of tungsten allows creating an electrical measurement tool for nanotechnology and high-performance instrument for probe nanolithography. It is shown that the use of modified cantilevers for the diagnostics of submicron structures allows one to minimize the artefacts of AFM images, as well as to increase the accuracy of the obtained results.

Characterization of field-emission cathodes based on graphene films on SiC

The properties of a point field-emission cathode representing a structure in the form of a silicon carbide tip coated with a thin graphene film are assessed. For the point cathode with the graphene coating, the current–voltage characteristics are constructed in the Fowler–Nordheim coordinates; the work functions φ of the point cathode are calculated by their slope. The possibility of forming heavily doped n+-SiC on the point surface by the sublimation of low-threshold field emission cathodes with low threshold electric fields and field-emission currents is shown.

Modeling of the Substrate Topography upon Nanosized Profiling by Focused Ion Beams

This paper presents the results of a mathematical model developed for calculating two-dimensional topography of the substrate surface when etching by a focused ion beam (FIB). A simulation of the two-dimensional relief of the substrate when irradiated by the FIB was carried out. An algorithm and software were developed making it possible to forecast the parameters of the surface relief depending on the characteristics of the ion beam and scanning system. The algorithm takes into account the redeposition of the sputtered material. The adequacy of the model is confirmed by a comparison with the results of experimental investigations.

Studying the resolving power of nanosized profiling using focused ion beams

The results of experimental studies of the resolving power and accuracy of nanosized profiling using focused ion beams (FIBs) are presented. Dependences of the resolving power on the ion beam current were obtained for the boron-doped (10 ohm cm (100)) silicon substrate during FIB etching. It has been established that the best resolution upon silicon etching determined by the average thickness of the etched line is 15–52 nm and corresponds to ion beam currents of 1–30 nA. It has been shown that the precision in the formation of a topological pattern on the substrate surface increases with the decreasing magnitude of the ion beam current in the range of 0.5 pA to 1 nA, and the relative error in the formation of the nanostructure decreases from 5.10 to 0.07. The results of our research can be used to develop manufacturing processes when creating submicron structures and elements of nanoelectronics and nanosystem technology by using FIB.

Analysis of modes of nanoscale profiling during ion-stimulated deposition of W and Pt using the method of focused ion beams

In this work the results obtained in experimental studies of conditions of the nanoscale profiling of a silicon substrate surface under the ion stimulation of W and Pt deposition by a Ga+ ion beam are represented. It is shown that, according to combinations of process conditions, deposition, or etching processes, conditions of the formation of transition structures can also be implemented. It is found that the rate of ionstimulated deposition of W and Pt averages 8 nm/min and 50 nm/min for ion-beam currents of 2.3 pA and 7.9 pA, respectively, and the rate of ion-beam etching of a silicon substrate is 6 nm/min and 55 nm/min for ion-beam currents of 2.3 pA and 111.4 pA respectively. With the use of these results, the modes are determined and a prototype of sensing element of tunnel accelerometer is formed using focused ion beams (FIBs). The results can be used to develop manufacturing methods of generating patterns of nano- and microelectronics and nano- and microsystem engineering on the basis of FIBs.

Planar nanosized field emission cathodes on the basis of graphene/semi-insulating silicon carbide fabricated by focused ion beam

We investigate the field emission properties of planar graphene structures with nanosized interelectrode distance. The graphene was obtained by thermal decomposition of silicon carbide in vacuum. Planar field emission structures on the basis of graphene on semiinsulating SiC were fabricated by using focused ion beam. We have performed current-voltage measurement on graphene/SiC field emission cathodes. The planar field emission structures showed a threshold voltage less than 1 V.

Study of Ion Beam Including Deposition Modes of Platinum Nanosized Structures Using by Focused Ion Beams

The results of experimental studies of the Pt structure with the thickness ranging from (0.48 ± 0.1) to (24.38 ± 0.1) nm ion beam including deposition by focused ion beam are presented. The rate of ion beam including deposition of Pt, which depending on the modes varies from (0.28 ± 0.02) to (6.7 ± 0.5) nm/s, is determined experimentally. The deviation of Pt lateral structure sizes from those preset by the template decreases from (29.3 ± 0.07)% to (2.4 ± 0.2)% depending on the deposition duration. By the thicknesses of Pt nanosized structures larger than 3 nm, their specific resistance amounts to (23.4 ± 1.8) Ohm cm and weakly depends on the thickness. The results can be used for developing the technological processes used to form the structures of microelectronics sensorics, nanoelectronics, and nano- and microsystem engineering.

Study of the field emission graphene/SiC nanostructures using scanning probe microscopy

We investigated the topology and electrical characteristics of the field emission graphene/SiC nanostructures using scanning probe microscopy. The effect of design of graphene/SiC nanostructures on field emission properties was estimated. The current-voltage characteristics were measured at different rounding-off radii of the emitting top and the interelectrode distances.