Field Emission Vacuum Magnetic Sensors

The project will build on work already under way at UCL to develop a novel planar vacuum magnetic sensor. The device will exploit the effect of the Lorentz force on a stream of field-emitted electrons. Field emission will be achieved by creating a sharp silicon tip by photolithography and positively biasing gate electrodes to produce a stream of electrons in vacuum. The electrons will be detected using a split anode, which will be fabricated on the same wafer, and will therefore be in the plane of the device. Applying a magnetic field perpendicular to the device will produce a deflection of the electrons, detectable as a change in the differential anode-cathode current.The proposed research will address issues identified in the first generation of devices, including control of tip geometry, gate and anode geometry, control of etch process, and optimisation of device layout.As well as magnetic field sensing, the application of the devices to the generation of UV light will be investigated.