Wear Resistance of N+-Implanted Silicon Investigated by Scanning Probe Microscopy

Abstract

A scanning probe microscope with a 80 nm radius diamond tip was used to investigate the wear resistance of single-crystal silicon and N+ -implanted silicon. The N+ implantation conditions were 35 to 150 keV and 5 × 1016 ions/cm2 . The N+ concentration depth profile was analyzed by using secondary ion mass spectrometry, and the chemical structure of N+ -implanted silicon was also analyzed by using x-ray photoelectron spectroscopy. The following results were obtained. The maximum N+ concentration on the ion-implanted silicon shifted further below the surface and the thickness of the high ion concentration region increased with the implantation energy. The high N+ concentration region using multiple energies of 35–150 keV during the same ion implantation process was wider than that for the N+ -implanted silicon using a single energy. The wear resistance of ion-implanted silicon was higher than that of single-crystal silicon. The N+ -implanted silicon using multiple energies during the same ion implantation process showed higher wear durability than that of the N+ -implanted silicon using a single energy. The Si2p spectrum of the high N+ concentration region implied a structure similar to a Si3 N4 film, which resulted in higher wear resistance.