Electron emission from polycrystalline silicon field emitter arrays coated with a thin diamond-like carbon layer

The emission current has been reported to be highly enhanced for Si and Mo emitters by diamond-like carbon (DLC) coating. The emission mechanism of DLC coated emitters, however, has not been elucidated. Furthermore, since DLC is ordinarily deposited on needle-shaped emitter tips, the shape of the emitter tips may be modified by the DLC coating, e.g., atomic scale kinks are formed on the emitter tips by the coating and the electric field concentration on the tips is enhanced consequently. On the other hand, the mold method using anisotropic etching reproduces the same shape of emitters, because the emitter shape is almost determined by a crystallographic structure of the mold. Therefore, we have employed the transfer mold method to fabricate DLC coated poly-Si emitter arrays. The paper describes enhancement in electron emission from poly-Si emitter arrays by DLC coating and discusses the emission mechanism.