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KCN solution treatment of amorphous hydrogenated silicon (a-Si:H) is a new technique for passivation of Si dangling bonds, capable to eliminate the interface states as well as a part of the bulk defects. It is based on the formation of Si–CN bonds by the cyanide treatment. The films were deposited on crystalline silicon (c-Si) and Corning glass substrates and subsequently chemically modified by KCN and HCN solutions. The latter solution was used as a passivation agent for the first time. Different cyanidization solutions in MeOH and water were tested. The X-ray diffraction and optical reflectance spectra of treated a-Si:H films were measured and analyzed. The optical thickness of intrinsic a-Si:H deposited on c-Si, obtained from the reflectance spectra, was apparently changed using HCN 0.1 M water solution. The X-ray measurements indicate a modification of the structure at the intrinsic a-Si:H/c-Si interfaces. The results were compared with those obtained on p-type of a-SiC:H/c-Si and a-SiC:H/glass, a-Si:H/c-Si structures. [Copyright &y& Elsevier]

Abstract: In order to determine an appropriate incident angle of low-energy (350-eV) oxygen ion beam for achieving the highest sputtering rate without degradation of depth resolution in SIMS analysis, a delta-doped sample was analyzed with incident angles from 0° to 60° without oxygen bleeding. As a result, 45° incidence was found to be the best analytical condition, and it was confirmed that surface roughness did not occur on the sputtered surface at 100-nm depth by using AFM. By applying the optimized incident angle, sputtering rate becomes more than twice as high as that of the normal incident condition. [Copyright &y& Elsevier]

Abstract: A diamond-based mold could be fabricated for glass imprinting by applying a replica method using CVD diamond film growth on a precisely patterned Si master substrate with arrays of square-arranged microlens (10×10μm2 in size). After the hot filament chemical vapor deposition (CVD) process, the diamond mold was obtained through dissolution of the Si substrate. The surface roughness (RMS) of the diamond mold could be drastically decreased from 52.9nm to 0.5nm by using the post reactive ion etching (RIE) process with fluorocarbon gases as well as by lowering the film deposition temperature. We evaluated the morphology of the diamond mold pattern from our cross-sectional observations by focused ion beam (FIB) etching, and we examined the crystal structure of the mold via Raman scattering spectroscopy. Fabrication of glass microlens array devices was demonstrated by imprinting the fabricated diamond-based mold on a soda-lime silicate glass and a quartz glass. We also characterized the mold releasability and its shape transcription properties. [Copyright &y& Elsevier]

Abstract: The properties of ultra-thin oxide/Si and very-thin oxide/Si structures prepared by wet chemical oxidation in nitric acid aqueous solutions (NAOS) and passivated in HCN aqueous solutions were investigated by electrical, optical and structural methods. n- and p-doped (100) crystalline Si substrates were used. There were identified more types of interface defect states in dependence on both post-oxidation treatment and passivation procedure. On samples prepared on n-type Si, continuous spectrum of defect states of 0.05–0.2eV range and discrete defect traps, ∼E CB −0.26eV and ∼E CB −0.39eV, were found. All mentioned defects are related with various types of Si dangling bonds and/or with SiO x precipitates. Post-metallization annealing of investigated MOS structures reduced the interface defect density and suppressed the leakage currents. It did not change spectral profile of interface defect states in the Si band gap. In addition, there are presented following two optical phenomena: relation between amplitude of photoluminescence signal of NAOS samples and parameters of chemical oxidation process and quantum confinement effect observed on samples containing Si grains of size less as ∼2nm. [Copyright &y& Elsevier]

Abstract: Non-Gaussian photoluminescence peaks observed in a-Si:H-based structures at 6K are interpreted as a consequence of the presence of different phases in material. Thin films of amorphous silicon deposited on glass substrate have been analyzed. The main aims of the contribution are (i) analysis of numerical data obtained by fitting procedure and (ii) formulation of corresponding conclusions in terms of structural properties of sample. Spectrum of a-Si:H-based samples can be interpreted as superposition of photoluminescence signals arising from two domains with different degrees of structural disordering. By our knowledge this result corresponds to real situation from view of structural properties of amorphous hydrogenated silicon. Under certain circumstances, decomposition of photoluminescence spectrum can give information of geometrical structure of sample. [Copyright &y& Elsevier]

Abstract: Formation of defect states on semiconductor surfaces, at its interfaces with thin films and in semiconductor volumes is usually predetermined by such parameters as semiconductor growth process, surface treatment procedures, passivation, thin film growth kinetics, etc. This paper presents relation between processes leading to formation of defect states and their passivation in Si and GaAs related semiconductors and structures. Special focus is on oxidation kinetics of yttrium stabilized zirconium/SiO2/Si and Sm/GaAs structures. Plasma anodic oxidation of yttrium stabilized zirconium based structures reduced size of polycrystalline silicon blocks localised at thin film/Si interface. Samarium deposited before oxidation on GaAs surface led to elimination of EL2 and/or ELO defects in MOS structures. Consequently, results of successful passivation of deep traps of interface region by CN− atomic group using HCN solutions on oxynitride/Si and double oxide layer/Si structures are presented and discussed. By our knowledge, we are presenting for the first time the utilization of X-ray reflectivity method for determination of both density of SiO2 based multilayer structure and corresponding roughnesses (interfaces and surfaces), respectively. [Copyright &y& Elsevier]

Abstract: In this contribution we present new experimental facts concerning evolution of the a-Si:H photoluminescence (PL) spectra, recorded at 6K, induced by both formation of very thin oxide layer in the surface region of the semiconductor by nitric acid solutions and passivation of a-Si:H defect states using HCN aqueous solutions. a-Si:H layers were deposited on both n-type of crystalline Si and the Corning glass. The analysis of the set of PL spectra – their interpretation – indicates that two explanations of blue shifts of the PL band maxima are possible. The first is connected with formation of several structurally different a-Si:H-based phases inside the amorphous matrix and/or with the Street model of recombination of localized electron-hole pairs coupled with the optical phonon in Si. Additionally, as it was stated, the wet chemical oxidation of 1μm thick a-Si:H layers deposited on the glass can induce formation of hydrogenated micro-sized a-Si grains. Passivation procedure performed in the HCN solution can transform an equivalent part of the a-Si:H semiconductor to a-Si:CN. If the multiphase model is accepted for interpretation of the PL spectra then the following main PL transitions related with different phases were observed: 1.20, 1.25, 1.38, 1.41, 1.44, and 1.48eV. [Copyright &y& Elsevier]

Abstract: Dominant aim of the paper was to verify the existence of the Si m H n clusters in a-Si:H layers. Thin layers were deposited by plasma-enhanced chemical vapor deposition (PECVD) on both glass and crystalline silicon substrates. Their IR and structural properties were investigated by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction at grazing incidence angle (XRDGI). We have found that the layer probably consists of larger structurally ordered parts corresponding to Si m H n clusters and separated groups of (Si-H x ) N . The ordered parts could be identified as some of Si m H n clusters ranging from (10, 16) to (84, 64) represented by corresponding vibration frequencies in three following IR regions: 600–750, 830–900 and 2080–2180cm−1. XRDGI measurement indicates that diffraction maximum at around 2Θ=28° can be attributed to an existing Si m H n cluster. [Copyright &y& Elsevier]

Abstract: An aim of the contribution is focused predominantly on investigation of electrical interface properties of MIS structures consisting of silicon-based substrates, which were passivated by 1.5–12nm silicon dioxide, silicon nitride and/or silicon oxy-nitride layers. Substrates of different structural properties were used—crystalline Si (c-Si), amorphous hydrogenated silicon (a-Si:H), and silicon layer deposited by plasma enhanced chemical vapor deposition (PECVD). A stress was laid upon structures prepared on n moderately doped c-Si. The paper presents also changes of structural properties of a-Si:H surface after Ar low energy beam impact. For the first time we are presenting important results concerning utilization of X-ray diffraction with β filter in investigation of a-Si:H cluster structure. Considerable part of the contribution is devoted to investigation of electrical properties of Al/Si3N4/Si (2–3nm)/GaAs structures with aim to clarify the particular effect of the ultrathin Si interlayer in the structure. Our observations indicate that the silicon interlayer can act as delta doping of GaAs and/or as quantum well. Therefore, the experimental results are compared and discussed with calculated ones obtained by application of our theoretical description of electron emission of quantum well. [Copyright &y& Elsevier]

Abstract: This paper describes the deposition of PZT/lanthanum nickel oxide (LNO) electrode thin-film capacitor on a Si(100) substrate with a chemical solution deposition (CSD). Highly (100)-oriented LNO film with a perovskite structure was deposited by annealing at 700°C from a precursor solution of La(NO3)3 and Ni(CH3COO)2. In addition, highly (100)&(001)-oriented PZT/LNO capacitor was deposited on LNO/Si substrate by annealing at 600°C, showing P r =18μC/cm2 and E c =36kV/cm. Furthermore, the resultant PZT/LNO thin-film capacitor exhibited no fatigue up to 108 switching cycles. [Copyright &y& Elsevier]

To furnish semiconductor surfaces at device fabrication, control of micro-structures is expected of the most importance in the near-future. Highly sensitive measurement of desorption from Cl-adsorbed Si(1 1 1) surface indicated that a diffusive process plays an important role on the surface. The desorption barrier was estimated to be 2.2 eV from temperature-dependence of time-course in isothermal desorption, suggesting the desorption site contains distortion. Defects, which may be steps or clusters, are the dominant sites where the associative reaction occurs. In STM images, clusters were observed at step edges, as well as growth of pits and defects. From comparison of the desorption with high temperature STM images, a cluster pins the step movement to form step bunches. Interaction between clusters through the step movements makes clusters aligned. Ordered structures can be obtained when velocity of the surface diffusion matches the rate of the chloride desorption. [Copyright &y& Elsevier]

The cleaning method using cyanide solutions has been developed to remove heavy metals such as copper (Cu) and nickel (Ni) from Si surfaces. Immersion of Si wafers with both Cu and Ni contaminants in potassium cyanide (KCN) solutions of methanol at room temperature decreases these surface concentrations below the detection limit of total reflection X-ray fluorescence spectroscopy of ∼3×109 atoms/cm2. UV spectra of the KCN solutions after cleaning of the Cu-contaminated Si surface show that stable copper-cyanide complexes are formed in the solution, leading to the prevention of the re-adsorption of copper in the solutions. From the complex stability constants, it is concluded that the Cu(CN)43- is the most dominant species in the KCN solutions. [Copyright &y& Elsevier]