Microanalysis of AFM Tips Coated with Cerium Oxide

2001 ◽  
Vol 7 (S2) ◽  
pp. 1236-1237
Author(s):  
Shelley R. Gilliss ◽  
Jeffrey K. Fairer ◽  
N. Ravishankar ◽  
Mark G. Schwabel ◽  
C. Barry Carter

Cerium oxide is widely used for chemomechanical polishing (CMP) of silicate glasses. Uses include finishing of optical elements and planarizing dielectrics in the semiconductor industry. This study is designed to investigate the fundamentals of the cerium oxide/silica CMP process by measuring the interaction force between silicate glasses and cerium oxide. Surface forces involved in the polishing of glass by a cerium oxide abrasive can be studied in a controlled manner by measuring sample-tip interactions between a glass substrate and a cerium oxide tip in an atomic force microscope (AFM). Commercially available AFM tips have been coated with thin, uniform films of cerium oxide. By using a square pyramid tip as a template for the shape of the cerium oxide film, challenges related to irregular or blunt tip shape can be overcome. However, complete characterization of structure, shape and chemical composition is required before useful information can be obtained using the AFM.

Author(s):  
Uday Chippada ◽  
Xue Jiang ◽  
Lulu Li ◽  
Rene Schloss ◽  
Bernard Yurke ◽  
...  

Hydrogels have been used as substrates by many researchers in the study of cellular processes. The mechanical properties of these gels play a significant role in the growth of the cells. Significant research using several methods like compression, indentation, atomic force microscopy and manipulation of beads has been performed in the past to characterize the stiffness of these substrates. However, most of the methods employed assume the gel to be incompressible, with a Poisson’s ratio of 0.5. However, Poisson’s ratio can differ from 0.5. Hence, a more complete characterization of the elastic properties of hydrogels requires that one experimentally obtain the value of at least two of the three quantities: Poisson’s ratio, shear modulus, and elastic modulus.


2010 ◽  
Vol 16 (5) ◽  
pp. 636-642 ◽  
Author(s):  
Christopher J. Tourek ◽  
Sriram Sundararajan

AbstractThree-dimensional atom probe tomography (APT) is successfully used to analyze the near-apex regions of an atomic force microscope (AFM) tip. Atom scale material structure and chemistry from APT analysis for standard silicon AFM tips and silicon AFM tips coated with a thin film of Cu is presented. Comparison of the thin film data with that observed using transmission electron microscopy indicates that APT can be reliably used to investigate the material structure and chemistry of the apex of an AFM tip at near atomic scales.


2012 ◽  
Vol 187 ◽  
pp. 197-200
Author(s):  
Tae Gon Kim ◽  
Quoc Toan Le ◽  
Samuel Suhard ◽  
Marcel Lux ◽  
Guy Vereecke ◽  
...  

Atomic force microscope (AFM) with inclined sample measurement and hydrophobic functionalized AFM probe was used to visualize the sidewall of low-k pattern and allowed to characterize the hydrophobic characteristics on the sidewall after low-k etch. To functionalized the AFM probe, 1H,1H,2H,2H-Perfluorodecyltrichlorosilane (FDTS) as a hydrophobic film was coated on an AFM probe. Because of the magnitude of the phobic-phobic interaction force and the tip forced to make a phase shift. Using this technique the visualization and characterization of the etch residue on the low-k sidewall can be successfully performed. It is shown that the investigation toward an effective chemical clean for the etch residue removal could be applicable.


Author(s):  
S.F. Corcoran

Over the past decade secondary ion mass spectrometry (SIMS) has played an increasingly important role in the characterization of electronic materials and devices. The ability of SIMS to provide part per million detection sensitivity for most elements while maintaining excellent depth resolution has made this technique indispensable in the semiconductor industry. Today SIMS is used extensively in the characterization of dopant profiles, thin film analysis, and trace analysis in bulk materials. The SIMS technique also lends itself to 2-D and 3-D imaging via either the use of stigmatic ion optics or small diameter primary beams.By far the most common application of SIMS is the determination of the depth distribution of dopants (B, As, P) intentionally introduced into semiconductor materials via ion implantation or epitaxial growth. Such measurements are critical since the dopant concentration and depth distribution can seriously affect the performance of a semiconductor device. In a typical depth profile analysis, keV ion sputtering is used to remove successive layers the sample.


Author(s):  
Kathleen M. Marr ◽  
Mary K. Lyon

Photosystem II (PSII) is different from all other reaction centers in that it splits water to evolve oxygen and hydrogen ions. This unique ability to evolve oxygen is partly due to three oxygen evolving polypeptides (OEPs) associated with the PSII complex. Freeze etching on grana derived insideout membranes revealed that the OEPs contribute to the observed tetrameric nature of the PSIl particle; when the OEPs are removed, a distinct dimer emerges. Thus, the surface of the PSII complex changes dramatically upon removal of these polypeptides. The atomic force microscope (AFM) is ideal for examining surface topography. The instrument provides a topographical view of individual PSII complexes, giving relatively high resolution three-dimensional information without image averaging techniques. In addition, the use of a fluid cell allows a biologically active sample to be maintained under fully hydrated and physiologically buffered conditions. The OEPs associated with PSII may be sequentially removed, thereby changing the surface of the complex by one polypeptide at a time.


Author(s):  
Y. Cheng ◽  
J. Liu ◽  
M.B. Stearns ◽  
D.G. Steams

The Rh/Si multilayer (ML) thin films are promising optical elements for soft x-rays since they have a calculated normal incidence reflectivity of ∼60% at a x-ray wavelength of ∼13 nm. However, a reflectivity of only 28% has been attained to date for ML fabricated by dc magnetron sputtering. In order to determine the cause of this degraded reflectivity the microstructure of this ML was examined on cross-sectional specimens with two high-resolution electron microscopy (HREM and HAADF) techniques.Cross-sectional specimens were made from an as-prepared ML sample and from the same ML annealed at 298 °C for 1 and 100 hours. The specimens were imaged using a JEM-4000EX TEM operating at 400 kV with a point-to-point resolution of better than 0.17 nm. The specimens were viewed along Si [110] projection of the substrate, with the (001) Si surface plane parallel to the beam direction.


1982 ◽  
Vol 10 (1) ◽  
pp. 37-54 ◽  
Author(s):  
M. Kumar ◽  
C. W. Bert

Abstract Unidirectional cord-rubber specimens in the form of tensile coupons and sandwich beams were used. Using specimens with the cords oriented at 0°, 45°, and 90° to the loading direction and appropriate data reduction, we were able to obtain complete characterization for the in-plane stress-strain response of single-ply, unidirectional cord-rubber composites. All strains were measured by means of liquid mercury strain gages, for which the nonlinear strain response characteristic was obtained by calibration. Stress-strain data were obtained for the cases of both cord tension and cord compression. Materials investigated were aramid-rubber, polyester-rubber, and steel-rubber.


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