Mechanism of non-saturated field electron emission from gated p-type Si tips

Gated p-type Si tip arrays with the same gate area (A
_G
) but various tip numbers (N
_tip
) were investigated to clarify the mechanism of non-saturated electron emission. It was found that the N
_tip
/A
_G
ratio determines the current increasing rate (dI/dV
_G
) of the non-saturated emission. A surface depletion/inversion dominated electron supply model that considered the local Joule heat effect was proposed to interpret the variation of the increasing rate of the non-saturated current. Less emitter in an array would lead to a higher average current on each tip, and thereby much local Joule heat to induce a stronger non-saturated emission. This work clarifies the mechanism of non-saturated emission from gated p-type emitters, and shows that the current increasing rate can be modified by changing the N
_tip
/A
_G
ratio. The findings are crucial for designing reliable and controllable Si-based electron sources.