Beyond-CMOS Tunnel FET Simulator: MOSFET vs Band-to-Band…

What is a MOSFET?

A Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is the cornerstone of modern digital electronics. It operates by controlling the flow of charge carriers, typically electrons, through a channel between source and drain terminals when a voltage is applied to its gate terminal.

The operation relies on thermionic emission, where electrons are heated up enough to overcome the potential barrier at the semiconductor-metal interface.

Understanding Band-to-Band Tunneling

In contrast to MOSFETs, a Tunnel Field-Effect Transistor (TFET) utilizes quantum tunneling to transport charge carriers. This mechanism allows electrons to pass through an insulating barrier without needing to overcome the thermal energy barrier.

The key advantage of TFETs is their ability to operate at much lower voltages and with higher on-state currents, potentially leading to faster and more power-efficient devices.

live demo · related simulation● LIVE

Comparing Thermionic Emission vs Band-to-Band Tunneling

Thermionic emission in MOSFETs is a classical process where electrons are emitted from the source electrode into the channel due to thermal excitation. This process is probabilistic and requires a significant amount of energy, typically around 60 mV/decade for each decade increase in current.

Band-to-band tunneling in TFETs, on the other hand, involves quantum mechanical effects where electrons can pass through an insulating barrier without needing to overcome thermal energy barriers. This process is deterministic and can occur at much lower voltages, offering a path to overcoming the limitations of MOSFETs.

Why Does This Matter?

The ability to reduce power consumption while maintaining high performance is crucial for future electronics, especially in mobile devices and data centers.

TFETs represent a potential breakthrough technology that could enable the continuation of Moore's Law beyond current CMOS limits.

Frequently asked questions

How does band-to-band tunneling differ from thermionic emission?

Band-to-band tunneling relies on quantum mechanical effects to transport electrons through an insulating barrier, while thermionic emission requires thermal excitation for electrons to overcome the potential barrier.

What are the advantages of using TFETs over MOSFETs?

TFETs can operate at much lower voltages and with higher on-state currents, potentially leading to faster and more power-efficient devices compared to MOSFETs.

Can TFETs completely replace MOSFETs in all applications?

While TFETs show promise for high-performance and low-power applications, they may not be suitable for all types of circuits due to their complex fabrication process and limited availability at this stage.

What is the significance of the 60 mV/decade thermal limit in MOSFETs?

The 60 mV/decade thermal limit represents a fundamental limitation on how much current can be increased with each decade increase in voltage, which TFETs aim to overcome through band-to-band tunneling.

Try it live

Everything above runs in your browser — open Beyond-CMOS Tunnel FET Simulator: MOSFET vs Band-to-Band Tunneling and change the parameters while it is running. Nothing is installed, nothing is uploaded, the whole model lives in one tab.

▶ Open Beyond-CMOS Tunnel FET Simulator: MOSFET vs Band-to-Band Tunneling simulation