Research On Fabrication Process And Performance Of Nano-vacuum Channel Devices

The wide application of early vacuum electronic devices benefited from their remarkable characteristics that they could work under high frequency and high power conditions,but the difficulty of device integration hindered its further development.The development of new vacuum devices is not only due to the particularity of the emitter material,but also the nano-channel has a prominent position in the entire device structure.The nano-channel has a certain scale so that the electrons in the channel are not interfered by the lattice scattering and directly carry out the ballistic trajectory.In a non-strict vacuum environment,electrons can be transferred from the emitter to the collection stage.In addition,the device can be integrated and miniaturized in process,combining the advantages of vacuum electronic devices with solid-state devices,thereby expanding the devices The scope of application.The main research content of this paper is based on the lateral nano-channel structure,using magnetron sputtering film deposition,ultraviolet lithography and FIB and other processes to prepare planar nano-channel diodes,back-gate nano-channel transistors and double-side-gate nano-channels.The field emission performance of the device is researched and analyzed through two aspects of simulation and experimental testing.The specific work includes:(1)Collect and sort out the research data on nano-channel structure devices at home and abroad,compare the characteristics of horizontal nano-channel structure and vertical nano-channel structure,and introduce several applications of nano-channel structure devices.(2)Briefly introduce the principle of field-induced electron emission,outline several key parameters that affect field emission performance,and analyze the relationship between the shape and size of the emitter and the local field strength and emission current through simulation.Taking the back-gate nano-channel structure as an example,the influence of the gate on the emission current is studied.Finally,the influence of terahertz wave radiation on the electric field distribution,resonance frequency and field enhancement in the structure is analyzed.(3)Introduced several kinds of nano-channel structure device preparation and its characterization test system,gave a brief overview of graphene transfer and characterization analysis.(4)Based on the special structure of nano-channel,this paper proposes three different device structures: planar nano-channel diode,back-gate nano-channel transistor and double-side-gate nano-channel structure.The preparation process methods of the three device structures are introduced separately,and the two processes of magnetron sputtering deposition of thin films and ultraviolet lithography are summarized in specific process experiments.Field emission performance tests were conducted on etched structural devices with different sizes and morphologies.The study found that the introduction of emitter tips and the reduction of the nanometer channel width will improve the electron emission performance of the devices.The structure with a 90° tip has been tested.Repeatability test and comparison of tests under different vacuum environments revealed that the structure has better repeatability and good stability under different atmospheric pressure environments.Finally,through the field emission test of the back-gate nano-channel structure and the double-side gate nano-channel structure,it is found that the addition of the gate can well improve the electron emission performance of the device and effectively reduce the opening electric field of the device.