The Gate Current in MOSFETs Versus Planar-NOI Devices

What is it about?

Recently reported, the Nothing On Insulator (NOI) device is based on the tunneling thru a ultra-thin insulator placed between two semiconductors. A direct implementation of the NOI transistor that requires a vertical cavity etching in Si of 2nm width is a difficult technological task. Therefore, this paper proposes a simpler structure, based on the planar Si-technology. Rotating the NOI structure by 900, the width of the cavity becomes the thickness of the cavity. If the vacuum is replaced by oxide, results a MOS capacitor without lateral junction but with lateral drain that is called p-NOI (planar-NOI variant). The p-NOI structure is simulated in Atlas and the results are compared with measured currents thru the gate of fabricated MOSFETs. The main conduction mechanism is Fowler-Nordheim and secondary is quantum tunneling. The tunneling currents of the p-NOI structures obeys to the exponential law and are similar to the gate MOSFET currents. The currents are dominated by the insulator thickness and the gate voltage.

Featured Image

Why is it important?

In conclusion, the Fowler-Nordheim mechanism was firmly demonstrated to be the main tunnelling current component thru the p-NOI structure, being in agreement with the gate current simulated thru a standard MOSFET and a real MOSFET of 5nm oxide.The gate current mainly depends on the insulator type and thickness and gate voltage.