US Patent 7508122 Planar gated field emission devices

In a field emitter (100) including a substrate (110), the substrate (110) has a substantially non-conductive top substrate surface (112). A conductive cathode member (130) is disposed on the top substrate surface (112) and has a top cathode surface (132). A conductive gate member (120) is disposed on the top substrate surface (112) and is substantially coplanar with the cathode member (130). An emitter structure (140) extends away from the top cathode surface (132). The gate member (120) is spaced apart from the cathode member (130) at a distance so that when a predetermined potential is applied between the cathode member (130) and gate member (120), the emitter structure (140) will emit electrons.