Method of making an integrally gated carbon nanotube field ionizer device

A method of making an integrally gated carbon nanotube field ionization device comprising:

• forming a first insulator layer on a first side of a substrate;
• depositing a conductive gate layer on said first insulator layer;
• forming a cavity in said substrate by etching a second side of said substrate to near said first insulator layer, wherein said second side is opposite said first side and wherein a portion of said first insulator is over said cavity;
• etching an aperture in said portion of said first insulator layer and said conductive gate layer to form an aperture sidewall;
• depositing a second insulator layer on said substrate and said first insulator layer and said aperture sidewall and said conductive gate layer;
• removing said second insulator layer from the top surface;
• depositing a metallization layer over said second insulator layer;
• depositing a catalyst layer on said metallization layer;
• and
• growing a carbon nanotube from said catalyst layer.