Surface treatment and surface coating of silicon field emitter array

The objectives of this research were to fabricate ungated Si field emitter arrays (FEA's), and then to identify ways to improve the performance of the emitters.; In the first and second chapters, the basis of the research, including background, theory, and the goals of the research is presented. The third chapter discusses the fabrication methods used to form the ungated Si FEA's. The fourth chapter gives the details about surface treatment procedures used to improve initial operation. The fifth and the sixth chapter discuss the different surface coating materials used to study the emission properties of the Si field emitters. The seventh chapter summarizes the work and suggests possible follow up research.; The four surface treatments discussed in chapter four employ, respectively, residual gas ions, low-energy electron-stimulated desorption, a hydrogen-enhanced residual gas atmosphere, and a plasma of a Ar (96%) and H₂ (4%) gas mixture. The method, using the hydrogen-enriched residual gas atmosphere is very unique in that it uses getters to produce the hydrogen rich atmosphere. The method, using a plasma of Ar (96%) and H₂ (4%) gas mixture, is an effective in-situ cleaning procedure, which can be performed prior to packaging the devices.; In chapters five and six is a comparison of the field-emission properties of the Si FEA coated with various materials, including (1) nanoparticle clusters of diamond and gallium nitride (GaN), (2) a thin film of ultrananocrystalline diamond (UNCD), (3) a lead zirconate titanate (PZT) coating, and (4) carbon nanotubes. Among the above coatings, the conformal coating of UNCD produced electron emission at an extremely low threshold field of between 2 to 5 V/μm. A further study of the behavior of electron emission from UNCD-coated Si FEA during in-situ exposure to H₂, N₂, and Ar respectively showed that when the emitting surface is exposed to H ₂, at 10−5 Torr and 10−4 Torr, the initial emission current (2 μA) increases by a factor of 2.7 to 4. When exposed to N₂ or Ar, a reduction of the emission current resulted, for an ambient of up to 10−5 Torr. These effects are reversible, as evidenced in that the emission current returned to its original value after the chamber was restored to the base pressure of 8 × 10 −10 Torr.