| Prebreakdown and breakdown characteristics of narrow vacuum gaps and insulator-bridged gaps relevant to vacuum microelectronic devices such as Field Emission Displays (FEDs) have been investigated for the first time. Particularly, breakdown and prebreakdown characteristics of vacuum gaps with broad area electrodes, needle-plane vacuum gaps in micron/submicron range, and vacuum and insulator bridged gaps with metal thin film electrodes are presented. Due to lack of experimental data in the literature about breakdown of micrometric size gaps, data obtained in this dissertation form a database for the design of vacuum microelectronic devices. Different mechanisms of electrical breakdown initiation have been analyzed. A theoretical approach based on the electrode surface instability under the high electric field has been developed to calculate critical electric field for breakdown. A theoretical model for electron emission from a conical protrusion with zero tip radius (conical point) on a plane surface is proposed for the first time. Current-voltage and breakdown characteristics of large Field Emission Arrays (FEAs) have been investigated. Conformal mapping technique was deployed to calculate electric field and electron trajectories in a Field Emission Display with linear (2-dimensional) cathode. Electron emitter structures based on silicon carbide have been investigated for the first time. Electron emission at low electric fields has been obtained from carbon-silicon carbide based emitters and at moderate electric fields from polycrystalline SiC films. Due to the unique properties of silicon carbide, SiC based emitters have large potentials for high voltage, high power applications. |
