Uneda M.,Kanazawa Institute of Technology |
Uneda M.,Kyushu University |
Maeda Y.,Kanazawa Institute of Technology |
Ishikawa K.-I.,Kanazawa Institute of Technology |
And 4 more authors.
Journal of the Electrochemical Society | Year: 2012
In chemical mechanical polishing (CMP) process, the removal rate is affected by the actual contact conditions between the wafer and the polishing pad. Further, the free abrasives in the slurry attack the wafer at the regions of actual contact. The polishing pad is one of the most important consumable materials in CMP since the pad surface texture changes during wafer polishing and substantially influences the actual contact conditions. Therefore, methods for quantitative evaluation of the pad surface texture have been proposed by various research institutes. We have developed a novel method for the quantitative evaluation of the polishing pad surface texture; this method is based on contact image analysis using an image rotation prism. We have proposed the use of four effective evaluation parameters: the number of contact points, the contact ratio, the maximum value of the minimum spacing of the contact points, and the half-width of the peak of the spatial fast Fourier transform (FFT) of a contact image. We determine the changes in the polishing pad surface texture on the basis of the proposed evaluation parameters in serial batch polishing tests. In particular, we focus on the relationships between the proposed evaluation parameters and the removal rate, which changes with an increase in the number of batch polishing tests. The evaluation parameters are linearly correlated with the removal rate. Hence, the removal rate is improved not only with an increase of the number of contact points and the contact ratio but also with a decrease in the size of the cohesion regions and the spacing between the contact points. © 2011 The Electrochemical Society.
Tajima F.,Yokohama National University |
Nishiyama Y.,Yokohama National University |
Hiroi N.,NAMIKI PRECISION JEWEL CO. |
Hiroi N.,NEC Corp |
Hashimoto Y.,Adamant Kogyo Co.
Journal of the Optical Society of America A: Optics and Image Science, and Vision | Year: 2010
A plane-polarized laser wave with a wavelength of 441.6 nm illuminates a cladding optical fiber with a diameter of about 18 to 38 μm at normal incidence. A measured angular distribution of the intensity of the scattered wave corresponds well with the differential cross section of a rigorous theoretical calculation of a coaxial double cylinder over a wide range of scattering angle. The diameter and refractive index of the cladding and core of the illuminated part of a fiber have been determined accurately for each uncertainty. © 2009 Optical Society of America.
Iwaya K.,Tohoku University |
Shimizu R.,Tohoku University |
Aida H.,NAMIKI PRECISION JEWEL CO. |
Hashizume T.,Tohoku University |
And 2 more authors.
Applied Physics Letters | Year: 2011
The electronic states of silicon donors in a wide gap semiconductor, β-Ga2O3 (100), have been studied using low-temperature scanning tunneling microscopy. We observe one-dimensional rows along , as expected from the crystal structure. In addition, substitutional Si donors are identified up to the fourth subsurface layer with clear spectroscopic features at the bottom of the conduction band. The decay length of each subsurface Si donor is systematically measured, and reasonably agrees with a picture of the Si donor in bulk β-Ga2O3. These results strongly suggest that Si impurities are shallow donors and responsible for the high electrical conductivity of β-Ga2O3. © 2011 American Institute of Physics.
Namiki Precision Jewel Co. | Date: 2014-08-27
A bending device to bend a flexible tube from inside electrically includes an electric actuator to drive a movable shaft electrically along the longitudinal direction of the tube in the axial direction and in the rotational direction, and an elongated member of which one end is connected to the movable shaft and the other end is connected to the inner surface of the tube at the location distanced, in the longitudinal direction of the tube, from the connecting point connecting the one end of the elongated member and the movable shaft, the connecting point connecting the one end of the elongated member and the movable shaft being located eccentric to the center of the movable shaft so that the towing direction of the elongated member towed by retreating the movable shaft changes along the circumferential direction by rotation of the movable shaft.
ADAMANT Co. and Namiki Precision Jewel Co. | Date: 2015-05-14
Printed circuit boards made of low temperature co-fired ceramics; printed wiring boards made of low temperature co-fired ceramics; circuit board embedded with micro electro mechanical systems; packages for semiconductor integrated circuits, packages for electronic and electric components.