Fabrication of Micron-Scale Diamond Field Emitter Arrays for Dielectric Laser Accelerators

We have recently established a capability to fabricate diamond field emitter array (DFEA) cathodes at Los Alamos National Laboratory (LANL). The DFEA cathodes are proposed to be utilized as an electron beam source for a compact laser accelerator. DFEAs are produced using a mold-transfer process. With wet etching and dry oxidation, micron pyramidal-shapes are formed on a Si substrate. Next, a layer of diamond is seeded and grown on the substrate. The sample is brazed on the molybdenum (Mo) substrate with TiCuSil, and Si and SiO2 layers are removed by using potassium hydroxide (KOH) and buffered oxide etchant (BOE), respectively. We test fabricated DFEA cathodes on our field emission test stand. In this paper, we describe the detailed process of fabrication and discuss the quality of some fabricated samples.