4H-Silicon Carbide Field Emitters for High Power Applications

Field emission is the enabling technology for the next generation of 3D medical imaging: static-digital tomosynthesis [1] which promises low radiation dose, low power consumption, rapid acquisition time, and portability. Thus, increasing the availability and accuracy of diagnosis for the early detection and treatment of disease and injury. However, the need for high electron currents and acceleration voltages results in the destruction of the emission structure due to material melting [2] and/or thermal runaway [3]. These effects impose a barrier in the development static-digital tomosynthesis devices that need to be overcome. Recent advances in the simulation of thermal-field emission and its heat effects from semiconductors [4] enables material selection and emitter design to meet the specifications for high power applications. Here we present (1) simulation results that establish that 4H-SiC emitters yield between 4 to 10 times more current, depending on the convention, before emitter destruction when compared against silicon, and (2) experimental evidence in several samples that support the simulation results.