Stable and low noise field emission from single p-type Si-tips

Single gated p-type Si-tips with two different tip radii were fabricated. An emission current of 2.40 mu A was measured for the sharp-edged tip at a voltage of 170 V. In contrast, a stable and reproducible emission behavior was observed with an increased tip radius resulting in a pronounced saturation region between 90 V and 150 V, but merely an emission current of 0.55 mu A at 150 V. More remarkable is the stable emission behavior with fluctuation of +/- 4 % during a measurement period of 30 minutes. The integral emission current in a homogeneous tip array (16 emitters) showed nearly the same I-V characteristics compared to the single tip and is therefore, most dominated by only a stable single tip in the array.