A new self-aligned process for fabrication of microemitter arrays using selective etching of silicon

Field electron emitter arrays (FEAs) have been fabricated by a not el self-aligned process. In this process the crystal-orientation dependent (anisotropic) and doping density dependent etching characteristics of single crystal Si are fully utilized. The emitter is formed by depositing a material in a mold prepared by anisotropic etching and thermal oxidation of Si. The gate is made of highly boron doped single-crystal Si, which acts as the etching mask for the mold formation. Gate/emitter spacing is determined by well-controlled ion implantation and thermal diffusion processes. FEBs with WSi2 emitters have been fabricated. The results demonstrate a small dispersion in gate/emitter spacing 3 sigma = 0.19 mu m where sigma is the standard deviation. FEB operation at about 10 V is demonstrated.