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Field emission plays a major role in determining the dynamics of charged particles in microgaps ~ 10 μm. While characteristics of positively charged direct current Townsend microdischarges are relatively well-studied, post-breakdown modes have received limited attention in the past. In this work, PIC/MCC simulations are used to model field emission driven microplasmas operating at current densities higher than those encountered before gas breakdown occurs. A quasi-neutral region is shown to exist even in gaps as small 5 μm with plasma number densities ~ 1022 1/m³. A simple sheath model is derived and validated using PIC/MCC simulations. Current voltage characteristics obtained using the model display two branches with positive and negative slopes similar to the abnormal glow and arc modes encountered in traditional macroscale plasmas. Field emission can hence potentially be used to confine plasmas in extremely small gaps thereby paving the way for their use in certain unique applications such as microscale etching. [ABSTRACT FROM AUTHOR]