Field emission characteristics of SiC capped Si tip array by ion beam synthesis

Abstract

High dose carbon implantation into Si tip array was performed to synthesize SiC/Si heterostructure tip array. This was done using a high beam current density metal vapor vacuum arc ion source. Silicon tip arrays were prepared by anisotropic chemical etching. An implantation energy of 35 keV using a dose of 1.0 ×1018 ions/cm2 was performed. The array was subsequently annealed in argon ambient at 1200°C, for various times to form the SiC surface layer. Scanning electron microscopy shows that the Si tips were sharp and uniformly arranged. X-ray photoelectron spectroscopy confirmed that a thin SiC surface layer had been formed. Results show that electron emission properties measured in ultrahigh vacuum depended on the sample treatment. A typical turn-on field was 15 V/μm when the emission current density reaches 1 μA/cm2. This compares with a turn-on field of about 35 V/μm for an unimplanted Si tip array. © 1999 American Vacuum Society.