Abstract: A method of monitoring and adjusting the position of a wafer with respect to an ion beam including setting the position of a wafer holder so that a wafer to be held therein is positioned at a tilt angle of 45 degrees and a twist angle of 45 degrees with respect to the path of an ion beam; positioning a n-type wafer without screen oxide in the wafer holder; implanting boron species into a region of the wafer at 160 KeV and a dose level of 5.0×1013 atoms/cm2; periodically measuring the sheet resistivity of a implanted wafer and readjusting the wafer tilt angle when the sheet resistivity is greater than 30 ohms/square.

Abstract: A multi-ocular kaleidoscope comprised of two transparent, semi-spherical shells connected into a transparent, spherical shell for containing transparent liquid and colored bits of glass or plastic. The two semi-spherical shells have each an internally threaded circular projection on its outer wall at the center and five internally and externally threaded semi-circular projections around its edge. Seven circular projections are thus formed on the outer wall, after the two semi-spherical shells are connected into a spherical shell, respectively for mounting seven pieces of visual tubes which have each three mirrors fastened therein and connected in a triangular structure.