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One of the electrical characterization techniques of semiconductor structures with nanometer spatial resolution is scanning spreading resistance microscopy (SSRM). The applicability of SSRM technique for characterization of GaAs structures with n-type doping fabricated by metalorganic vapour phase epitaxy (MOVPE) was examined. The influence of scaling effect on the nanometer size AFM tip--semiconductor electrical characteristics was described. The results of characterization of device structure of magnetic field sensitive field effect transistor were presented. [ABSTRACT FROM AUTHOR]

The lithography is a main technology process which determines the properties of semiconductor devices. The resolution of optical lithography is insufficient for creation of submicrometer patterns, like, e.g., gate electrode in HEMT transistors. Thus, a novel technique that uses AFM technique and common photolithography was proposed. In the paper, the results of nanoscratching lithography were presented and discussed. Also the transmission and root mean square of thin metal films measurements were summarized. [ABSTRACT FROM AUTHOR]

The lithography is a basic microelectronic process which determines properties of fabricated device. The resolution of optical lithography applied nowadays is insufficient for creating high resolution patterns such as gate electrode in transistors. The scaling ability is the major motivation for undertaking experiments to elaborate high resolution lithography techniques. The atomic force microscope (AFM) is commonly used as tool for creation patterns in sub-micrometers resolution. In this paper, the results of simulations of electromagnetic field behavior during passing the gap with a size smaller than the wavelength of the optical lithography light source are presented. Also results of the nanoscratching lithography prepared for various parameters of force that are applied to the tip are summarized. [ABSTRACT FROM AUTHOR]

In the paper results of investigation of the influence of low concentration hydrogen on stress changes in thin catalytic metal films were discussed. The concentration of H was altered from 6 ppm to 1% of hydrogen (6N) in nitrogen (6N). Silicon beams covered with palladium or platinum films of various thicknesses were anchored at one end and their deflection at the other end was measured by atomic force microscope. Stress changes were determined by application of modified Stoney formula and compared with results of computer modelling. The influence of stress caused by hydrogen absorption on the alteration of output characteristics of AIII-N based hydrogen sensors was excluded. The time dependence of stress in metallic films for various hydrogen concentrations indicated dissociation limited mechanism of hydrogen absorption. [ABSTRACT FROM AUTHOR]

In this paper, a study of the influence of hydrogen (concentrations 6 ppm − 1%) on the work function of thin metallic films at moderately elevated temperatures is presented. The work function was measured indirectly by the observation of the surface potential of dedicated test structures using scanning surface potential microscope. Metallic layers with thicknesses of 10, 20, 30, and 50 nm were deposited on semiconductor substrates as well as on a thick gold layer. The investigations were focused on palladium thin films although a comparison to results obtained for platinum layers was also discussed. [ABSTRACT FROM AUTHOR]

A correlation of surface potential maps and photocurrent distribution images in metal-semiconductor-metal (MSM) structures allows to notice spatial nonuniformities in detector principle of operation. This effect exists only for low frequency modulation of optical excitation. This phenomenon was explained by the inhomogeneity of potential barriers and surface states density in heteroepitaxial gallium nitride layers caused by their columnar structure. [ABSTRACT FROM AUTHOR]

The lithography is a basic operation in the fabrication process of semiconductor devices. The scaling ability is the reason why the atomic force microscopy (AFM) nanolithograpy is currently studied in many laboratories. In the paper, the results of the mechanical AFM lithography, named nanoscribing or nanoscratching, are presented. In this method, the pattern is created by mechanical interaction between the AFM tip and a sample. This interaction requires the application of large forces in micronewtons scale. [ABSTRACT FROM AUTHOR]

In this paper, the results of investigation of the influence of cathode current on optical and dielectric AlNx thin-film properties are presented. AlNx films were prepared by pulsed DC reactive magnetron sputtering of Al target on substrates at room temperature. For characterization of fabricated test structures C-V spectroscopy, ellipsometry measurement and atomic force microscopy (AFM) were used. [ABSTRACT FROM AUTHOR]

Ohmic contacts to AlGaN/GaN heterostructures which have low contact resistance and good surface morphology are required for the development of high temperature, high power and high frequency electronic devices. One of the keys to the advancement of such devices is the understanding of ohmic contacts formation to epitaxial aluminium gallium nitride layers. The paper presents the investigation of Ti/Al/Ni/Au based ohmic contact to n-AlGaN/GaN heterostructures grown by LP-MOVPE technique. Multilayer metallization of Ti/Al/Ni/Au with thicknesses of 10/100/40/150 nm, respectively, was evaporated by an electron gun (Ti, Ni) and resistance heater (Al, Au). The contacts were annealed at RTA (rapid thermal annealing) system in nitrogen ambient atmosphere over the temperature range from 775 °C to 850 °C. The time of annealing process was 60 seconds. The morphology of Ti/Al/Ni/Au ohmic contacts to n-AlGaN/GaN heterostructures was studied as a function of the annealing process conditions by an optical microscope and AFM (atomic force microscope). Simultaneously, the electrical parameters of Ti/Al/Ni/Au ohmic contacts were studied as a function of the annealing process conditions by the current-voltage (I-V) method on dedicated test structures. The characteristic resistances of the Ti/Al/Ni/Au/n-AlGaN/GaN ohmic contacts were evaluated from the circular transmission line method (CTLM). The formation and deterioration mechanisms of the ohmic contacts to n-AlGaN/GaN hesterostructures were studied. One of the mechanisms of agglomerates enlargement during the thermal annealing of Ti/Al/Ni/Au metallization has been proposed. [ABSTRACT FROM AUTHOR]

The influence of grain structure of materials on optoelectronic devices performance was examined by light beam induced current (LBIC) technique. AlGaN metal-semiconductor-metal (MSM) detectors and polycrystalline silicon solar cells were examined. In case of AlGaN MSM structures, the effective region of carrier collection of contact electrodes was estimated as hundreds of nanometers. For these structures, the regions, where measured signals were two orders of magnitude larger than the average signal, were also observed. Measurements of polycrystalline solar cells allow us to determine the recombination activity of grain boundaries. LBIC method was applied to investigate layers quality used for MSM detectors and solar cells fabrication. [ABSTRACT FROM AUTHOR]