Single-crystal Si field emitter fabricated by anodization

A process for fabrication of field emitter arrays using anodization of single-crystal Si is demonstrated, when anodization is carried out in the dark on Si having n/p junctions, porous Si is preferentially formed in the p-type region. A needlelike tip structure can be formed beneath the unanodized n-type Si layer, since the anodization proceeds almost isotropically. The porous region can be easily oxidized and selectively removed by chemical etching. The shape of emitter can be controlled by changing the dimension of the n/p junction and varying the resistivity of p-type region. Fabrication of an emitter array and its field emission characteristic are reported.