Fabrication of diamond Schottky emitter array by using electrophoresis pre-treatment and hot-filament chemical vapor deposition

This paper presents the fabrication of multi-beam electron Schottky emitter array with integrated electron lenses. The integrated emitter array consists of boron-doped diamond heaters with a diamond tip, Si micro gate array and Si focusing lens array. The diamond film is selectively deposited using electrophoresis of diamond seed particles and a hot-filament chemical vapor deposition (HF-CVD) technique. The emitters, gate and lens array are electrically isolated from each other on a Pyrex glass substrate. The gate hole is 40 μm in diameter and situated below the emitters with a 20 μm gap. Electron emission performance of the fabricated diamond emitter was characterized. As increasing the heating current into the heating element with the emitter, the emission current increases. When heating the diamond emitter at a voltage of 2.8 V, an emission current of 490 nA has been observed at an electric field of 0.36 V/μm.