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Cell attachment is of paramount importance in implant design, bioreactor design, tissue engineering and the design of non-fouling surfaces. Surface roughness is a significant factor that affects cell attachment. To explore the impact of roughness characteristics, micromachining approaches can be used to fabricate surfaces with controlled microscale topography. When optical microscopy is employed to study cell attachment to optically opaque micropatterned surfaces, one needs to separate the area of an image coated with cells from the background. Manual cell counting can be used to assess the amount of attached cells. However, this process is very time consuming, when the studied surface is larger than several square millimeters. This paper describes an approach for the automatic estimation of the area of cells attached to the surfaces of micro-patterned optically opaque platforms. Saccharomyces cerevisiae yeast cells were used to test the developed approach. The approach uses image registration and segmentation tools available in MathWorks MATLAB R2020b Image Processing Toolbox. The factors that affect the accuracy of the developed approach (magnification, contrast and focus) as well as the ways of improving the results are discussed. more...

The aim of the study was to investigate how cerebral vasospasm, vasodilation and haemorrhage under artificial circulation conditions during cardiopulmonary bypass affect transcranial duplex ultrasonography measurements. A description of transcranial duplex ultrasonography and phantom development is provided. Measurements were made using a commercially available ultrasound system and cardiopulmonary bypass machine, water phantom and 32% glycerol solution with cornstarch. The experiments showed that the cerebral blood vessel condition in artificial circulation affects transcranial duplex ultrasonography measurement limit values. The most sensitive parameter for blood vessel condition changes is Peak Systolic Velocity (PSV) for which changes were observed in 100% of cases. The most insensitive was Time-Averaged Peak-Velocity (TAPV), and Minimum Diastolic Velocity (MDV) for which changes were observed in 83% of cases. more...

The effect of 6 MeV gamma photons on thermally stimulated exoelectron emission (TSEE) spectra of MgO films was studied. The films were fabricated on Si/SiO2 substrates using the extraction-pyrolytic method. The crystalline structure and surface morphology of the films were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). TSEE spectra of MgO films had emission peaks at about 450 oC and 525 oC. The area under the TSEE peaks increased after repeated TSEE measurements. In the case of gamma-irradiated films, the percentage increase in the area depended on the radiation dose, decreasing linearly with an increase in the radiation dose from 0 to 80 Gy. The results suggest that gamma radiation reduced the density of trapped electrons present in the as-grown MgO films or created competing hole traps that inhibited TSEE from the films. more...

It is more common to perform non-invasive examination during general anaesthesia to ensure effective perioperative patient care. To achieve these results, researchers and clinicians are seeking out different technologies and developing new equipment. One such apparatus is a cerebral oximeter, which is used during cardiac surgery with cardiopulmonary bypass for neuroprotection management for reducing risk of postoperative neurological injury (cerebral stroke, neurocognitive dysfunction, and cerebral haemorrhage). A cerebral oximeter performs non-invasive transcutaneous measurements using near infrared radiation to assess the oxygenation of tissues. The objective of the study was to determine if the angle and thickness of a patient’s skull affects measurements. Intralipid water solution, gelatine, and ink were used to make six phantoms with skull thickness ranging from 6 to 11 mm. All phantoms were bent froma0to20 degrees angle. The cerebral oximeter SOMETICS INVOS 5100C was used to perform regional oximetry measurements. For skull thickness of 11 mm, the rSO2 was 45.8% (SD 0.96); for skull thickness of 10 mm, the rSO2 was 45.25% (SD 2.22); for skull thickness of 9 mm, the rSO2 was 32% (SD 1.63); for skull thickness of 8 mm, the rSO2 was 17% (SD 1.83); for skull thickness of 7 mm, the rSO2 was 15% (SD 0); for skull thickness of 6 mm, the rSO2 was 15% (SD 0). No significant changes were observed regarding the angle of the skull phantom. The thickness of the bone layer of the skull phantom affected the regional oximetry results, whereas the angle of the skull did not affect it. more...

The purpose of this study was to investigate the effect of Zn doped CaP coatings prepared by micro-arc oxidation method, as a possible approach to control MgCa1 alloy degradation. All the prepared coatings comprised a calcium deficient CaP phase. The control in this evaluation was performed with undoped CaP coating in SBF solution at body temperature (37 ± 0.5⁰C). The investigation involved determination of microchemical, mechanical, morphological, properties along with anticorrosive, cytocompatibility and antibacterial efficacy. The effect of sterilization process on the properties of the surfaces was also investigated. The results showed that the addition of Zn into CaP increased the corrosion resistance of MgCa1 alloy. Moreover, the adhesion strength of the coatings to MgCa1 alloy was enhanced by Zn addition. In cytotoxicity testing of the samples, extracts of the samples in MEM were incubated with L929 cells and malformation, degeneration and lysis of the cells were examined microscopically after 72 h. The results showed that all samples were cytocompatible. The degradation of MgCa1 alloy in the simulated body fluids (SBF) or DMEM was decreased by coating with CaP. Moreover, the degradation rate of CaP was further decreased by adding a small amount of Zn into the CaP matrix. The samples having CaP coatings and Zn doped CaP coating demonstrated antibacterial efficacy against E.coli. As a result, coating of magnesium alloy with Zn-doped CaP decreased the degradation rate, increased the corrosion resistance, cytocompatibility and the antibacterial effects of the alloys. more...

Single-layered and multi-layered 20–60 nm thick silicon nitride (Si3N4) dielectric nanofilms were fabricated using a low-pressure chemical vapour deposition (LPCVD) method. The X-ray photoelectron spectroscopy (XPS) confirmed less oxygen content in the multi-layered nanofilms. The capacitors with Si3N4 multilayer demonstrated a tendency to a higher breakdown voltage compared to the capacitors with Si3N4 single layer. Si3N4 nanofilms and capacitors with Si3N4 dielectric were exposed to 1 kGy dose of gamma photons. Fourier transform infrared (FTIR) spectroscopy analysis showed that no modifications of the chemical bonds of Si3N4 were present after irradiation. Also, gamma irradiation did not influence the breakdown voltage of the capacitors but decreased their capacitance measured at 1 MHz frequency. However, the multi-layered capacitors were not affected by radiation more than the single-layered capacitors. These findings suggest a promising process to fabricate nano-scaled multi-layered Si3N4 capacitors with improved breakdown voltage characteristics and resistance to ionizing radiation. more...

Physical vapor deposition (PVD) of metallic thin films is used extensively in the fabrication of semiconductor technology devices - use as of lately for them have grown. Tungsten (W) is a low resistivity, refractory metal, that is often deposited by PVD methods for use as a gate contact to semiconductor devices and due to the low work function and high thermal stability, W can be used for the fabrication of field emitters in microelectronics [1-3]. In order to monitor quality of the synthesized thin films by magnetron sputtering method, it is necessary to develop methodology suitable for the analysis of these thin films. Infrared spectrometry is a sensitive method for the analysis of chemical bonds, but W thin films contain weakly polar and non-polar W-W bonds, that cannot be directly detected by infrared spectrometry, therefore oxidation of W is selected as thermal oxidation method for detecting oxidized products for thin films of thickness 150 nm, for instance, W-O bonds. After oxidation, it was observed, that the oxidation of W thin films takes place already at a 600 °C in the air atmosphere. The Fourier transform infrared spectrometry (FTIR) spectra of modified coatings showed formation of additional new signals in the region of 700-900 cm−1 attributed to W-O, O-W-O, W=O bonds - formation of W-oxygen bonds on Si-SiO2 substrate was achieved. For coating homogeneity and production quality formation, additionally synthesized control samples are recommended for FTIR analysis. more...

The ability of cells to adhere to substrates is an important factor for the effectiveness of biotechnologies and bioimplants. This research demonstrates that the statistical distribution of the sizes of the cells (Saccharomyces cerevisiae) attached to the substrate surface correlates with the statistical distribution of electrical potential on the substrate’s surface. Hypothetically, this behavior should be taken into consideration during the processing of surfaces when cell adhesion based on cell size is required. more...

The effect of gamma irradiation on Gd2O3 films was studied using the thermostimulated exoelectron emission (TSEE) technique. The films were deposited on a glass and Si/SiO2 substrates using an extraction-pyrolytic method. Crystalline structure, chemical composition, film thickness and surface morphology were characterized by means of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The films were irradiated by 10 MeV gamma photons and TSEE was measured from the irradiated films. It was found that gamma irradiation decreases TSEE intensity and the area below TSEE spectral curves. A linear correlation between the relative decrease in the area and the delivered dose was observed in a dose range of 0–10 Gy. These findings suggest that gamma radiation might decrease the density of trapped electrons present in the as-grown Gd2O3 films or create competing electron traps that inhibit TSEE from the films. more...

The article is aimed to engineer strength and elastic modulus of a polymer composite material embedded with electrically charged silica nanoparticles. Ultraviolet radiation was in use to induct an electrical charge at surfaces of the nanoparticles. The specimens were tested under mechanical loading (tensile test). An electron emission by the loaded material surface was detected to indicate beginning of material destruction. The electrically charged nanoparticles embedded into the polymer composite material were able to control its strength and elastic module. An early destruction of the polymer composite (as it was identified because of the electron emission) appeared at ~0.018 of relative elongation, in an elastic deformation range. more...

This article is focusing on electrical functionalization of biomaterial&rsquo, s surface to enhance its biocompatibility. It is an overview of previously unpublished results from a series of experiments concerning the effects surface electrical functionalization can have on biological systems. Saccharomyces cerevisiae cells were used for biological experiments. The hydroxyapatite (HAp) specimens were used to investigate influence of structural point defects on the surface electrical charge. Threshold photoelectron emission spectroscopy was used to measure the electron work function of HAp and biologic samples. The density functional theory and its different approximations were used for the calculation of HAp structures with defects. It was shown that the electrical charge deposition on the semiconductor or dielectric substrate can be delivered because of production of the point defects in HAp structure. The spatial arrangements of various atoms of the HAp lattice, i.e., PO4 and OH groups, oxygen vacancies, interstitial H atoms, etc., give the instruments to deposit the electrical charge on the substrate. Immobilization of the microorganisms can be achieved on the even surface of the substrate, characterized with a couple of nanometer roughness. This cells attachment can be controlled because of the surface electrical functionalization (deposition of the electrical charge). A protein layer as a shield for the accumulated surface charge was considered, and it was shown that the protein layer having a thickness below 1 &micro, m is not crucial to shield the electrical charge deposited on the substrate surface. Moreover, the influence of surface charge on the attachment of microorganisms, when the surface roughness is excluded, and the influence of controlled surface roughness on the attachment of microorganisms, when surface charge is constant, were also considered. more...

Modern semiconductor sensors which are used for gas detection are based on an MOS (metal–oxide–semiconductor) structure, but the usage of such sensors is limited due to its working principles. Over the last decade, MOS sensors have been combined with a UV-radiation source, but the sensing capabilities of a low gas concentration for those sensors are limited. In previous studies, the possibility to use optically stimulated semiconductors to sense acetone gas at lower concentrations was demonstrated [1]. Another study demonstrated the possibility to sense and determine various solvent gases, where acetone vapour showed the highest signal increase [2]. more...

An electron irradiation assisted photoelectron emission technique was developed to study charge traps for nanolayered Si3N4 and SiO2. Sharp emission peaks were induced by electron irradiation, with characteristic energies revealing their microscopic origins. Trap energies, originating from SiO2, were observed to shift depending on the electron irradiation dose and the thickness of Si3N4 nanolayers. Improved understanding of the characteristics of these defects can be informative towards the development of high performance nanocapacitor devices, in addition to furthering understanding of non-volatile memory devices. more...

Multilayer Si 3 N 4 consisting of Si 3 N 4 nanolayers with the total thickness 60 nm was deposited layer-by-layer in a low-pressure chemical vapor deposition process. Compared with the single-layer Si 3 N 4 , the multilayer Si 3 N 4 had one-third less oxygen concentration at the interfaces. This decreased density of electrically active centers of oxygen traps and improved quality of nanocapacitors with multilayer Si 3 N 4 dielectric. more...

The calcium phosphate coating was provided onto the titanium substrate because of the nanoarc coatings technology. Both surface morphology and electrical charge of the coating were measured at the nano/micro-scaled lateral resolution. The negative electrical potential was typical for sockets, however the positive one to the peaks of the roughness. The cells were mainly attached at the negatively charged sockets. The cells expressed both osteocalcin and alkaline phosphatase that are the osteoblastic molecular markers. more...

The unique biological properties of amber are well known. Amber particles that penetrate into the cellular matrix can potentially be used as markers of plant cell biological activity by identification of living cells in flow cytometry. However, there have been no studies on effect of amber particles on plant cells. The aim of this study was to determine effect of amber nano- and micro- (5 nm-3 μm) particles on somatic and gametic cells and to assess the possibility to use amber particles as alive plant cells markers. To reach the aim, fluorescence of cells was determined in the presence of amber particles, and amber components - spirit of amber and sodium succinate dibasic hexahydrate. Cell fluorescence was measured using a BD FACSJazz® cell sorter for several plants species (Argyranthemum frutescens, Cyclamen persicum, Hordeum vulgare and Linum usitatissimum) with and without treatment of amber. Differences between a control cell group (without amber treatment) and treated cell group with amber particles depended on plant species. The presence of amber components (alcohol soluble amber fraction and sodium succinate) in cultivation media mostly had no influence on cell fluorescence. The study showed that amber particles (size 5 nm-3 μm) can be used as living plant cell markers, as the presence of amber particles in plant cell cultivation media resulted in substantially increased plant cell fluorescence in all investigated species, and there was no detrimental effect of amber particles on plant cells. more...

In previous studies the possibility to use optically induced semiconductors to sense acetone vapors was demonstrated [1]. One of the studies demonstrated the possibility to sense and determine various solvent gases, where acetone vapor showed the highest signal increase [2]. In this study, two optical irradiation types (continuous and cyclical) are compared. more...

Modern radiation therapy (RT) technologies and the needs of molecular and micro radiobiology have necessitated the detection of radiation absorbed by micro/nano volumes. The possibility of developing a nano/micro-scale dosimeter is demonstrated via the use of prethreshold photoelectron and exoelectron emission from solid-state nanolayers (Si, bone) and nanofilms (ZrO2:PbS). The experiments indicate that the absorbed dose threshold depends on the detector origin. more...

Nanostructured hydroxyapatite (HAP) and its nanoparticles are widely used for implantation into the human organism. The biocompatibility of the implants depends very much on the interaction between the implant and the cells regenerating tissue to be connected to the implant. An implant surface electrical charged density plays an important role in these processes. Possible instruments managing the surface electrical potential of HAP are in the focus of this paper. Both theoretical and experimental results evidence that: - the surface electrical charge density of the nanoparticle depends on its size and shape; - the electrical charge density of HAP could be engineered by contact less technique because of deposition of the electrical charge from the external radiation source, surface couples reconstruction. more...

Poly methyl metha acrylate (PMMA) is widely in use for eye prostheses and contact lenses. The latter is under ultraviolet radiation of Sun. Therefore the PMMA properties could be influenced and bring the patient to discomfort, because of polymer surface wettability alteration. The latter is under the focus of the present research. Wettability and electron work experiments show similar tendencies, also high correlation has been found between electron work function and absorption minimum area. More interestingly - surface electrical potential depended on exposure under light. more...

In the current study, we have examined the possibility to improve the biocompatibility of the (TiZrNbTaHf)C through replacement of either Ti or Ta by Si. The coatings were deposited on Si and 316L stainless steel substrates by magnetron sputtering in an Ar+CH4 mixed atmosphere and were examined for elemental composition, chemical bonds, surface topography, surface electrical charge and biocompatible characteristics. The net surface charge was evaluated at nano and macroscopic scale by measuring the electrical potential and work function, respectively. The biocompatible tests comprised determination of cell viability and cell attachment to the coated surface. The deposited coatings had C/(metal+Si) ratios close to unity, while a mixture of metallic carbide, free-carbon and oxidized species formed on the film surface. The coatings' surfaces were smooth and no influence of surface roughness on electrical charge or biocompatibility was found. The biocompatible characteristics correlated well with the electrical potential/work function, suggesting a significant role of surface charge in improving biocompatibility, particularly cell attachment to coating's surface. Replacement of either Ti or Ta by Si in the (TiZrNbTaHf)C coating led to an enhanced surface electrical charge, as well as to superior biocompatible properties, with best results for the (TiZrNbSiHf)C coating. more...

It is known that there is a number of VOC (volatile organic compounds) in exhaled human breath that can be used as biomarkers [1, 2]. To reach screening of the patients the exhalation gas sensor should be light, cheap and sensitive. Semiconductor gas sensors can offer advantages in size, but they are characterized with a long response time, short lifespan, lack of selectivity [3, 4, 5]. more...

The results are based on the first principal modeling and calculations for HAP nanostructures as native as well surface modified, charged and having various defects (H and OH vacancies, H inter-nodes). HAP structures were studied using Local Density Approximation (LDA) method with calculations of Density of States (DOS) allow us analyzes the experimental work function data. Molecular modeling by HyperChem is confirmed by photo-electron monochromatic measurements up 6.5 eV and photo-luminescence data from synchrotron DESY experimental data up 30 eV values. Brief analysis of the influence of heating, microwave radiation, hydrogenation, x-rays and synchrotron radiation on Hydroxyapatite (HAP) surface is presented in this work. New data of the structure of hydroxyapatite are obtained. more...

Preliminary diagnosis of human diseases such as cancer and diabetes is possible via the detection of violate organic compounds (VOCs) contained in exhaled breath gases. A pre-threshold electron emission yield from a solid emitter depends on the gas molecules adhered to the emitter, if the electron work function is influenced. The paper demonstrates that pre-threshold electron emission from a silicon solid emitter could be employed to detect exhaled VOCs. more...

Ultraviolet (UV) radiation is able to cause biological changes at the cellular and molecular level. To study biological effects of UV radiation, UV detector is required. 10 monolayer thick ferroelectric P(VDF-TrFE) films consisting of 70% vinylidene fluoride (VDF) and 30% trifluoroethylene (TrFE), or P(VDF-TrFE 70:30), were investigated as a possible material of UV detector. The films were deposited on a glass substrate using Langmuir-Blodgett technique. Changes in surface electric potential of P(VDF-TrFE 70:30) films under influence of UV radiation were investigated by Kelvin force microscopy. A hypothesis was proposed that UV radiation was well absorbed by the glass substrate changing its surface charge. This charge in turn changed polarization of P(VDF-TrFE 70:30) film leading to changes in its surface electric potential. It was found that after 6 minutes of UV irradiation surface electric potential of P(VDF-TrFE 70:30) films decreased and no changes were observed further increasing irradiation time. However, surface electric potential of the bare glass substrate continued to decrease increasing irradiation time. It was also found that surface electric potential of P(VDF-TrFE 70:30) films relaxed to its initial value within half an hour after the irradiation was stopped. The relaxation obeyed exponential law. The study suggests that P(VDF-TrFE 70:30) films deposited on the glass substrate are sensitive to UV radiation and might be able to serve as a material for an UV dosimeter, however, further studies are required. more...

Wettability of the poly methyl methacrylate (PMMA) surface defines its biocompatibility being essential factor for biomedical applications. The processed surface degrades in time therefore the prostheses/lens should be repaired to keep the patient at a high life quality level. However the most common methods can be considered as sophisticated (plasma treatment, laser treatment, etc.). The research presents novel result on the PMMA surface wettability engineering by means of non-ionizing ultraviolet radiation (200–400nm). Results (electron work function (ϕ), photoelectron emission spectra, optical absorption) show alteration from hydrophobic to hydrophilic surface behaviour. Both the surface (photoelectron emission) and the bulk (optical absorption) interacting centres were influenced by radiation showing maximum effect after 45 minutes of irradiation. more...

The electronic structure and self-polarization of P(VDF-TrFE) Langmuir-Blodgett nanofilms were analyzed under temperature-driven phase transitions, according to their thickness, composition, and structural conformation. Both thermo-stimulated exoelectron emission (TSEE) spectroscopy and computational simulation, including quantum-chemical calculations from first principles, were carried out. PVDF and composite P(VDF-TrFE) (70:30) molecular chains as Trans and Gauche conformers, as well as crystal cells, were modeled for these TSEE analyses. The quantum-chemical calculations and the computational simulation were based on the density functional theory (DFT) as well as semi-empirical (PM3) methods. It was demonstrated that the energy of electron states, as well as the total energies of the studied P(VDF-TrFE) molecular clusters during phase transformation, is influenced by electron work function and electron affinity. Analysis was performed by combining TSEE experimental data with the computational data of t... more...

Radiation applied for therapy and diagnostics damages molecular/atomic couples of biotissues, bones being among them. As a result, electron peculiarities and mechanical behavior of the latter are altered. Correlation between strength of the irradiated bone and its electron features explored due to photo- and exoelectron emission measurements is reviewed. © 2001 Biomedical Engineering Society. more...

Hydroxyapatite (HAP) is in use to fabricate implants in dentistry and orthopaedy. To functionalise a surface of the HAP that has a direct contact to the human cells a surface electrical charge deposition is employed. The current technologies can not provide uniformity of the charge for contrarily situated surfaces. more...

We have applied novel technique for enhancing bone tissue formation on micro- and nanostructured calcium phosphate (CP) coatings. CP surfaces with “primitive” physical-chemical composition, which is not corresponding to last one in bone, have an active effect on functional properties of mesenchymal stromal cell pull (MSCP). The studied micro-CP coatings, characterized by marked roughness of surface had an osteoinductive potential up to 100 %. Relief of CP coatings from HAP nanoparticles (30–50 nm) does not practically differ from ones designed by use of HAP microparticles. Roughness of all CP nanocoatings had average Ra=5.13−6.43 µm and Rz=18.71−24.16 µm that was corresponded to CP microcoatings one. Probability of bone plate formation on CP nanostructured coatings was only 12.5 %. Hydrogenation of the CP surface layer increased its negative charge that was evaluated by means of photoelectron work function (ϕ) measurement. An increment of ϕ at the values of ≈0.1−1 eV was supplied. This had an effect on the directions of MSCP differentiation. For example, connective tissue growth was improved. For all this, probability of following ossification with growth of membrane reticulated bone was 20 %. Vice versa, decrease of ϕ led to primary formation of bone from bone marrow MSCP. Technique of intracellular RNA staining detected the actively synthesized osteoblasts and bone marrow stromal cells. The above evidences that hydrogenation of CP coatings could in situ effect MSCP differentiation in fibroblasts or osteoblasts associated with stromal cells of hemopoietic inducing microenvironment. more...

Rapid development of nanomaterials opens a wide horizon for their applications, medicine being one of them. Nanomaterials and nanodevices are in use both in the human body and as medical nanosensors. Reliable employment of materials requires trustworthy detection of their properties. Characterization of both the nanomaterials and nanosensors should be supplied at the nanoscaled dimension. To avoid disturbing gentle nanoobjects, measurements of them with contactless techniques are preferable. Low energy electron has a mean free path in a solid that is of the order of nanoscale. Therefore, a prethreshold (energy of the emitting electron is close to the electron work function) electron emission contactless spectroscopy could become an efficient instrument both for characterization of nanostructured materials and nanosensing. Weak emission (~ 10 -16 …10 -15 Q/cm 2 ) of electrons from a solid does not give a significant feedback to measurements in the sense of the negligible inducted electrical charge at the material surface (the density of the surface electrons in the solid is around 10 14 cm -2 ). The paper reviews photo-, dual-, and exo-electron emission fundamentals and their applications for the characterization of nanoobjects (concentration of pointlike imperfections, their annealing, migration, surface charge of nanoparticles, energy gap, electron density of states, thickness of thin films and interfaces between them and the substrate) as well as gas and ionizing radiation. The ways for medical applications are indicated. more...

A radiation treatment is used often to manufacture of semiconductor chips. Their surface layers excited by this way have the important role in reliability of produced devices. Thus, a response of the surface on the radiation affection is necessary to test. The problem may be solved using a method providing information about point defects inserted due to the considered treatment. Exoelectron spectroscopy (ES) has been developed to hit this target, taking into account an evaluation of the single imperfections concentration and their relaxation processes. more...

The photoelectron emission method and the special equipment have been developed to control processes of resistor, silicon dioxide and nitrite thin films. The main idea of the method is based on the difference of work functions of the film and a wafer. It is possible to test structural and phase properties of the films too. The above equipment has been incorporated with the industry instruments providing ion etching.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. more...

Physi. cal reasons provi di ng sensi ti. vi. ty of a photoerni ssi on current to a thi cknesses of a t,hI n fi 1 m and a doped surface I ayerare consi dered. Both a di fference between opt! cal properti es of a substrata and a film coated on it and dependence o fphotoelectric work function on electrical active admixture concentration are the main of them. Photoelectron emission has been applied to test objects having the thickness in order to I O2angstr oms. 2. INTRODUCTIONThe technol ogy of mi croci r cui t uses processes to pr ovi de thin films and doped surface layers. Their thickness Cd) is one of the quaIl ty parameters. The non—contact and non—destructi on I nstruments are the best to test d. This may be supplied, for instance, by means of photon exciting of electron emission from the tested speci men. Energy of photons i s, usually of severaleVE 1]. For such a case escaping depth of electrons L i s about IO.. .lO1cm [1,2]. So, this size CL) is typical for the anal ysi. s cons! der more...

Exoel ectr on anal yzes C EAD of poi nt defects both i n crystalline and amorphous semiconductors is considered. The below concentrati on threshol ds of poi nt defects and Ion—implanted impurities that may be estimated by this method are 10 .. . 10 17 -3cm and 10 13 1 -3 . . . 10 cm , correspondingly. Keywords: point defects, testing, semiconductors, exoelectron anal yzes. 2. PHYSYCAL PRINCIPLESExoel ectr on em! ssi on C LED is a process of el ectr on escapi ng into vacuum from a solid state when it is simultaneouslyheated and irradiated by ultra-violet light, the photon energy be! ng cI ose to the photoel ectr I c wor- k functi on. Current C I D of el ectr ons i s changed substanti al I y non—monotonously dur I ng rising of temperature CT) CF1g.1). IN I I 273 473 673 TK 873 F! g. I. Exoemi ssi on spectr urn C dependence I on T ) of crystal 1 i ne silicon irradiated by ions of Phosphor C100 keV)1. 120 / SPIE Vol. 2334 0819416673/94/$6.00 fbr 8 4 0 Downloaded From: http://proceedings.spiedigitallibrary.org/pdfaccess.ashx?url=/data/conferences/spiep/50544/ on 04/25/2017 Terms of Use: http://spiedigitallibrary.org/ss/termsofuse.aspx more...

Mechanical stresses change energy gap in semiconductors. Thus, a photoelectric work function is dependent on this effect. In such a view surface layers elastic deformations are recorded by measuring of photoelectron emission quantum yield.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. more...