Papers by Keyword: Atomic Force Microscope (AFM)

Abstract: The modified SiC slurry for CMP process was proposed in order to obtain high-quality surface of 150 mm SiC wafer and then tried to explain the mechanism of the effect of added transition metal ion to improve polishing characteristics of SiC crystal substrate. SiC substrate with using modified slurry exhibited slightly higher MRR value and lower platen temperature than those with using commercial slurries. The addition of transition metal ion into the slurry enhanced oxidation efficiency of SiC crystal surface and improved MRR and the quality of SiC surface.

Abstract: Self-assembled monolayers (SAMs) can be used for surface functional control to assist with pattern collapse prevention and as a protective layer to enable Area Selective Deposition (ASD). To be successful, these applications require the formation of a high-density, defect-free, so-called well-packed SAM at the nm scale. In this paper, we describe a method to map the nm scale defects of octadecyltrichlorosilane (ODTS) SAMs using a post-etching AFM analysis of the surface of the substrate and used this technique to develop a process to form high-density, defect-free SAM layer at the nm scale. This was achieved by optimizing the water concentration in the solvent for the precursor solution and annealing after SAM formation.

Abstract: This paper provides a comprehensive review of current nanoparticle analysis methods specifically designed for sub-20 nm particles. The techniques are categorized into three main groups: ensemble (I), single particle counting (II), and separating & counting (III) methods. The study further presents a comparative analysis of test results obtained using these three categories of methods on polydisperse polymer nanoparticles. For this investigation, four different tools capable of sub-10 nm particle analysis were utilized. The techniques employed in this study include dynamic light scattering (I), atomic force microscope (II), scanning mobility liquid particle sizer (III), and cryo-electron microscopy (I). The findings indicate that, for particles larger than 8 nm, the three tools—excluding dynamic light diffraction—yield similar results. Conversely, in the small size range (<7 nm), cryo-electron microscopy consistently demonstrates reliable outcomes.

Abstract: We have studied the microstructure of the growth surface of the 4H-SiC grown by the m-face solution growth. Atomic Force Microscopy (AFM) revealed the micro-striped morphology with the asperity of several nm in the band-like morphology region. The cross-sectional Transmission Electron Microscopy (XTEM) showed that the growth surface consisted of a bunch of nanofacets and vicinal surface. This peculiar morphology is totally different from that of conventional spiral growth on c-face, which can be closely related with the growth mechanism of the m-face solution growth.

Abstract: Two types of carrot defects with and without a shallow pit were found by mirror projection electron microscopy (MPJ) inspection in 4H-SiC epi wafer. Surface morphology and cross-sectional structure of prismatic stacking faults (PSFs) were investigated using MPJ and atomic force microscopy (AFM), transmission electron microscopy (TEM) and high-resolution scanning transmission electron microscopy (STEM). The depths of the surface grooves due to the PSFs, the stacking sequences around the PSFs and the structure of the Frank-type stacking faults which were connected to the PSFs were different. We discuss the difference between the two types of carrot defects.

Abstract: In order to understand the crystal defects of beta-gallium oxide (β-Ga₂O₃) in more detail, we classified the crystal defects of a 2-inch substrate of β-Ga₂O₃ (001) single crystal. As a result of observing the etch pits formed by molten alkali etching using scanning electron microscope (SEM) and atomic force microscope (AFM), we succeeded in observing six different etch pit shapes. These etch pit shapes are categorized into “Cicada I type”, “Cicada II type”, “Cannonball type”, “Trapezoid type”, “Bar type”, and “Shell type”. We consider that “Cicada I type” and “Cicada II type” are etch pit shapes caused by planar defects, and “Cannon ball type” is etch pit shapes due to dislocations. In addition, “Trapezoid type”, “Bar type”, and “Shell type” are deduced the result of surface morphology.

Abstract: The defect structure of Mg implanted GaN substrate was evaluated by TEM observations, AFM surface observations and Raman scattering spectroscopic analysis. Mg ions were implanted at room temperature (RT) and 500 °C. TEM results showed that the defect distribution along depth scale is different between RT and 500 °C condition. The several peaks originated from ion implantation were found from Raman scattering spectra and the characteristics of the defects by implantation were discussed. The crystal quality of the sample implanted at 500 °C was found to be better than that of RT by comparing the FWHM of the E₂ peak.

Abstract: This paper is dedicated to develop an atomic force microscope (AFM) system cou-pled with a high resolution optical microscope (OM), which serves to observe AFM image from a desired micro-area. The system employs through-the-lens optical path for detecting atomic force based on optical lever. By switching the objective lenses from low to high magni cation, a micro-area for obtaining AFM image can be easily found. AFM images of magnetic nanodotarrays with 300 nm and 150 nm pitches are obtained from two local micro-areas using the system. The results demonstrate the proposed prototype has the su cient function to nd out a micro-area for obtaining AFM image.

Abstract: In this paper, we present experimental measurements of slip length of deionized (DI) water flow on a silicon surface and a graphite surface by using atomic force microscope. The results show that the measured hydrodynamic drag force is higher on silicon surface than that on graphite surface, and a measured slip length about 10 nm is obtained on the later surface.

Abstract: Dip-pen nanolithography (DPN), based on atomic force microscope (AFM) system, is an effective method for nanoscale science and engineering, and the potential applications of DPN will be shown in the field of nanomechanics, nanomaterials, nanobiotechnology, nanomedicine. And the novel combined-dynamic mode DPN (CDDPN), rather than mostly used contact mode DPN or tapping mode DPN, becomes the important tool for the fabrication of nanodots with the direct-writing method of depositing the ink onto the hard silicon surface at the predetermined position, which is presented in the corresponding experiments. In addition, the size of nanodots gradually decreases in the diameter with the increase of the number of nanodots in the case of AFM tip dipping in ink once. However, the size in height does not monotonically reduce as the reduction of the ink, which is affected by the interaction among the relative humidity, AFM tip, substrate material, surface roughness, etc. For the better nanolithography quality of the nanodot, the nanolithography process, under the optimized process parameters, is accomplished once without the intermediate scan imaging process as much as possible.