Ni nanodots (NDs) used as nano-scale top electrodes were formed on a 10-nm-thick Si-rich oxide (SiO$_{mathrm{x}}$)/Ni bottom electrode by exposing a 2-nm-thick Ni layer to remote H$_{2}$-plasma (H$_{2}$-RP) without external heating, and the resistance-switching behaviors of SiO$_{mathrm{x}}$ were investigated from current-voltage ( extit{I--V}) curves. Atomic force microscope (AFM) analyses confirmed the formation of electrically isolated Ni NDs as a result of surface migration and agglomeration of Ni atoms promoted by the surface recombination of H radicals. From local extit{I--V} measurements performed by contacting a single Ni ND as a top electrode with a Rh coated Si cantilever, a distinct uni-polar type resistance switching behavior was observed repeatedly despite an average contact area between the Ni ND and the SiO$_{mathrm{x}}$ as small as $sim$ 1.9 $ imes$ 10$^{-12}$cm$^{2}$. This local extit{I--V} measurement technique is quite a simple method to evaluate the size scalability of switching properties.

We fabricated highly dense Si nano-columnar structures accompanied with Si nanocrystals on W-coated quartz and characterized their local electrical transport in the thickness direction in a non-contact mode by using a Rh-coated Si cantilever with pulse bias application, in which Vmax, Vmin, and the duty ratio were set at +3.0V, -14V, and 50%, respectively. By applying a pulse bias to the bottom W electrode with respect to a grounded top electrode made of ∼10-nm-thick Au on a sample surface, non-uniform current images in correlation with surface morphologies reflecting electron emission were obtained. The change in the surface potential of the highly dense Si nano-columnar structures accompanied with Si nanocrystals, which were measured at room temperature by using an AFM/Kelvin probe technique, indicated electron injection into and extraction from Si nanocrystals, depending on the tip bias polarity. This result is attributable to efficient electron emission under pulsed bias application due to electron charging from the top electrode to the Si nanocrystals in a positively biased duration at the bottom electrode and subsequent quasi-ballistic transport through Si nanocrystals in a negatively biased duration.

We have fabricated highly-dense Si nano-columnar structures accompanied with Si nanocrystals on W-coated quartz, and characterized their local electrical transport in the thickness direction using atomic force microscopy (AFM) with a conductive cantilever. By applying DC negative bias to the bottom W electrode with respect to a grounded top electrode made of 10-nm-thick Au on the sample surface, current images reflecting highly-localized conduction were obtained in both contact and non-contact modes. This result is attributable to electron emission due to quasi-ballistic transport through Si nanocrystals via nanocolumnar structure.

The copper nitride surface characteristics according to atmospheric pressure plasma (APP) and excimer ultraviolet (EUV) treatment were compared using XPS and AFM. As the result of XPS analysis result, in C1s, the organic material removal effect was greater for EUV treatment than for APP, and the oxygen content was found to be low. In Cu (933 eV) area, the shoulder peak of Cu compound was detected, and the reduction was greater for EUV processing than for APP. In the AFM phase image which could be analyzed using the superficial viscoelasticity, the same trend was observed. On the copper nitride surface, the weak boundary O layer is formed according to the clean processing, and such phenomenon was interpreted as a factor for lowering the affinity with polymer.

Silicon-quantum-dots (Si-QDs) with an areal density as high as 1012 cm - 2 were self-assembled on thermally-grown SiO2 by low pressure CVD using Si2H6, in which OH-terminated SiO2 surface prior to the Si CVD was exposed to GeH4 to create nucleation sites uniformly. After thermal oxidation of Si-QDs surface, two-dimensional electronic transport through the Si-QDs array was measured with co-planar Al electrodes evaporated on the array surface. Random telegraph signals were clearly observed at constant applied bias conditions in dark condition and under light irradiation at room temperature. The result indicates the charging and discharging of a dot adjacent to the percolation current path in the dots array.

We did an experimental study to investigate the effect of the thermal stress due to the heater for adjusting adaptive flying height (AFH) on the readability and instability of tunneling magnetoresistance (TMR) sensors. The slider head consists of a small heater nearby the read/write elements for controlling the clearance between the read/write elements and the recording medium of the magnetic recording system. It is firstly reported that the thermal stress from the AFH heater induces instabilities and caused head degradation. The thermal stress degrades the reader performance by inducing voltage fluctuations and large noise spikes that causes the magnetic recording system having poor bit error rate (BER). The open loop of the transfer curve indicates that the flipping of a synthetic antiferromagnet (SAF) edge magnetization causes these instabilities. The thermal stress reduces the exchange bias field and the energy barrier to flop the SAF edge magnetization. The dispersion and thermal stability of the antiferromagnetic (AFM) layer are the potential root causes of these SAF instabilities because the larger AFM dispersion in these heads gives less net stabilizing field to SAF layers that lowers the energy barrier to flop the SAF edge magnetization. Scanning electron microscope (SEM) images of these weak heads show rough surface and scratches close to the sensor element. The mechanical stress due to these scratches may additionally impact to the stabilizing field of the SAF.

Multiply-stacked structures of Si quantum dots (Si-QDs) in gate oxide are attracting much attention because of their potential importance to improve retention characteristics in a high density charge storage. In this work, we have fabricated 6-fold stacked Si-QDs with 2 nm-thick SiO2 interlayers, whose areal dot density and average dot size were 5.71011 cm-2 in each dot layer and 5 nm in height, and studied progress on electron distribution in 6-fold stacked Si-QDs with 2 nm-thick SiO2 interlayers from the measurements of temporal changes in the surface potential after electron charging and discharging locally at room temperature using an AFM/Kelvin probe technique in clean room air. First, by scanning an area of 22 µm2 with the AFM tip biased at +3 V with respect to the substrate in a tapping mode, the area was negatively charged due to electron injection from the substrate to the dot through the bottom tunnel oxide and subsequently, the central part of 100100 nm2 in the pre-charged area was scanned with the tip biased at -3 V to emit the electrons from the Si-QDs to the substrate. As a result, the negative charging level was markedly reduced in the central part in comparison to its peripheral region. And then, the surface potential of the negatively-charged peripheral region was decay monotonously with time as a result of progressive electron tunneling to the substrate. In contrast to this, the temporal change in the surface potential of the central part shows that the electron charging proceeds with time until the surface potential becomes almost the same as that in the peripheral region. This result can be interpreted in terms of lateral spreading of electrons stored in the Si-QDs layer due to the potential difference between the central part and its peripheral region more negatively charged.

A well-defined test structure of organic static-induction transistor (SIT) having regularly sized nano-apertures in the gate electrode has been fabricated by colloidal lithography using 130-nm-diameter polystyrene spheres as shadow masks during vacuum deposition. Transistor characteristics of individual nano-apertures, namely 'nano-SIT,' have been measured using a conductive atomic-force-microscope (AFM) probe as a movable source electrode. Position of the source electrode is found to be more important to increase current on/off ratio than the distance between source and gate electrodes. Experimentally obtained maximum on/off ratio was 710 (at VDS = -4 V, VGS = 0 and 2 V) when a source electrode was fixed at the edge of gate aperture. The characteristics have been then analyzed using semiconductor device simulation by employing a strongly non-linear carrier mobility model in the CuPc layer. From device simulation, source current is found to be modulated not only by a saddle point potential in the gate aperture area but also by a pinch-off effect near the source electrode. According to the obtained results, a modified structure of organic SIT and an adequate acceptor concentration is proposed. On/off ratio of the modified organic SIT is expected to be 100 times larger than that of a conventional one.

Hydrogenated germanium films were fabricated in the thickness range of 7-98 nm on SiO2 at 150 by an rf glow discharge decomposition of 0.25% GeH4 diluted with H2, and the nucleation and growth of Ge nanocrystallites were measured from topographic and current images simultaneously taken by a conductive AFM probe after Cr contact formation on films so prepared. We have demonstrated that current images show fine grains in comparison with topographic images and the lateral evolution of the Ge grains with progressive film growth. The contrast in current images can be interpreted in terms of the difference in electron concentration between nanocrystalline grains and their boundaries.

This paper focuses on the processing of carbon nanotubes (CNTs) alignment as molecular bridge. A magnitude of an alternative voltage of about 1 V with 1 MHz was applied between two electrodes containing CNTs in suspension. The CNT bundles were well stretched along the field line distribution. Two kinds of directions could be distinguished around the electrode: the parallel and the Gaussian. On the other hand, different lengths of CNT bundles were aligned from one electrode side to the other. Those which were more than 1 µm reached both sides of electrodes while the short one did not but followed the Gaussian distribution of electric field. The short CNTs represent an increasing interest of study as far as their flexibility, mechanical and electrical properties are concerned. That's basically because one of their sides ended on the substrate. Among the advantages of the alignment of the CNT is to control the current flux and the thermal conductivity in composite resins or as new materials for the development of novel single-molecular transistors.

AFM/STM observations were performed on sub nm thick C-Au-S film by co-operation process of plasma CVD and sputtering with using CH4, SF6 and Ar mixture gas and Au plate discharge electrode. From the refractive index values, the conductive granular molecules with a size of 0.4-0.6 nm were expected to exist in the film. For the film at thickness similar to the molecular size, Ra (arithmetic mean departures of roughness profile from the mean line) values were measured to be 0.712/6.10 nm by AFM/STM measurement, respectively. The one order large STM Ra value compared to the AFM Ra value suggests that the film contains conductive granular molecules.

Surface morphology and piezo response on SBT films were simultaneously measured by scanning probe microscopy. In a sample that had many short-circuited capacitor pads, some curious structures were observed on the SBT film surface. The piezo image partially did not correspond with the AFM image. Some specific grains were revealed to be piezo defects. Also observed were some smaller grains with flat surface, which showed good ferroelectricity. Next, we carried out simultaneous measurements of surface morphology and leakage current. The scanning at an intentionally high voltage was repeated until the leakage points were found. We found the leakage points, which were on some large grains, not at grain boundaries or on the flat smaller grains. In another SBT film derived from an unrefined source, many ferroelectric defects were observed despite there being no curious structures on the surface. Purity has an important bearing on the ability to avoid these defects. Thus, these nanoscopic investigations would greatly facilitate understanding of the mechanisms responsible for problems and enable optimization of the process conditions in device fabrication.

A method has been developed for evaluating the wear durability and adhesion characteristics of ultrathin overcoat films. The relationship between the wear depth and applied load or between the wear depth and number of scanning-scratch cycles is used in AFM nanowear tests. Inherent wear durability, which is independent of adhesion or substrate hardness, can be evaluated from the relationship between wear depth and applied load at relatively low loads, and the adhesion characteristics can be evaluated from the relationship at relatively high loads. Wear durability can be evaluated with a small number of scanning-scratch cycles and adhesion with a large number of cycles.

Force curves obtained from an elastic contact theory are shown and compared with experimental results. In the elastic contact theory, a pin-on-disk contact is assumed and the following interaction are taken into consideration; (i) elastic deformation, (ii) the specific energy of adhesion in the area of the contact, which is expressed as the difference between the surface energies and the interface energy, (iii) the long-range interaction outside the area of contact, assuming the additivity of the Lennard-Jones type potential, and (iv) another elastic term for the measurement system such as the cantilever stiffness of an atomic force microscope (AFM). In the limit when the stiffness is infinite, the theory conforms to Muller-Yushchenko-Derjaguin (MYD) theory. In the limit when the surface-surface interaction is negligible, the theory conforms to the analytical theory by Takahashi-Mizuno-Onzawa. In the limit when the stiffness is infinite and the long-range interaction outside the area of contact is negligible, the theory conforms to Johnson-Kendall-Roberts (JKR) theory. All parameters and all equations are normalized and the normalized force curve is obtained as the functional of only two parameters; (1) the normalized stiffness of the measurement system, and (2) the normalized distance which is used in the expression of the Lennard-Jones potential. The force-displacement plots are converted into force-penetration plots.

We have developed a new method of evaluating Si suface micro-roughness, by forming thin oxide in HCl/H2O2 solution and then measuring the concentration of chlorine atomes and the total charge in this oxide. It is shown that this oxide does not affect the surface micro-roughness, and the surface concentration of chlorine atoms incorporated in this oxide and the total oxide charge are proportional to the surface microroughness, obtained by AFM. From this correlation, it is possible to evaluate the surface micro-roughness for large areas compared with the areas of AFM measurement.