Noise Measurement and Analysis of Field Emission Current from Boron Doped Diamond

Boron-doped diamond films have been grown on the silicon substrate by the microwave plasma chemical vapor deposition technique. The deposited films were characterized by field emission scanning electron microscopy and Raman spectroscopy. The B₂O₃ concentration is varied from 1000 to 5000 ppm. It is observed that particle size decreases, with increase in B₂O₃ concentration and it is found to be 30 nm for 5000 ppm. The turn on field required to draw current density of 1 μA/cm² is found to be 0.80 V/μm for 5000 ppm B₂O₃ concentration films. Additionally, spectral analysis of field emission current is performed at base pressure of ~1 × 10^-8 mbar. The plot of field emission current time (I-t) shows “step” and “spike” like fluctuations characterized by 1/f^α type of behavior with α ~ 0.8. The fluctuations in the field emission current are attributed to different processes occurring on the emitter surface.