FABRICATION OF SI FIELD EMITTER TIP FOR A 3-DIMENSIONAL VACUUM MAGNETIC SENSOR

A new Si field emitter tip generating a cross-shaped electron beam was fabricated for a three-dimensional vacuum magnetic sensor (VMS) appli cation. The present tip is surrounded by a gate for field emission, an d a focusing lens is made in the same plane as the gate. The beam curr ent of about 50 nA was obtained with a single tip at the gate and lens voltages of 55 V and 10 V, respectively. The fabrication process and beam characteristics are described. Preliminary results such as linear ity and sensitivity of VMS using the present tip are also discussed.