Effect of the hybrid etching methods on the field emission characteristics of Mo-tip field emitter arrays

Changes of the electron emission properties of the field emitter arrays (FEAs) were studied with the variations of oxide etching methods for defining the gate hole. In this study, we introduced a new hybrid etching process, which combines wet and dry etchings for gate hole formation and two kinds of Spindt-type Mo-tip FEAs having different structures of gate insulator were fabricated on heavily doped n-type Si wafer: FEAs with a dry-type gate-insulator by dry etching (dry-type FEAs) and FEAs with a hybrid-type gate-insulator by hybrid etching (hybrid-type FEAs). We found that the field emitter formed by the hybrid-type method revealed less gate leakage current than that of the dry-type FEAs, in which the gate insulator edge lies at the same line with the edge of gate metal. Numerical simulation results agree well with the experimentally observed results. Furthermore, the emission properties for the hybrid-type FEAs were found to be more stable over the operating time than those of the dry-type FEAs. Therefore, we suggest that the FEAs formed by the hybrid etching method may be suitable for a high-performance field emission display.