Extension of lifetime of silicon field emitter arrays in oxygen ambient by carbon negative ion implantation

As the state of the art, ion implantation techniques require high-current ion beams with the lower energy, as the dimension of the devices becomes smaller. However, it is difficult to drive the lower-energy ion beams straightly, due to the huge ionic space charge. We proposed utilization of electron beam emitted from silicon field emitter arrays (Si-FEA) for compensation of the ionic positive space charge. One of the difficulties in utilizing Si-FEAs in ion implanter is such that the Si-FEA is easily affected by the residual gases, since the implantation generates gas molecules from photoresist materials. It is shown that the emission current decreases, especially in oxygen. One of the ways to protect the surface from oxidation is deposition of the material, which is highly resistant against oxidation, to the tip surface. We modified the surface of the Si-FEA by carbon negative ion implantation, in order to protect the surface from oxidation. In this paper we show the effectiveness of the carbon negative ion implantation to extend the lifetime of Si-FEAs.