Hot Carrier Degradation in Semiconductor Devices

Hot Carrier Degradation (HCD) arises when charge carriers in a transistor channel acquire sufficient kinetic energy to surmount local potential barriers or generate electron–hole pairs by impact ionisation. These high-energy carriers can become trapped in the gate dielectric or at the semiconductor–insulator interface, creating oxide traps and interface traps that shift threshold voltage, reduce carrier mobility and increase leakage currents. As device dimensions shrink below the 10 nm node, electric fields intensify and self-heating effects become more pronounced, accelerating trap formation and exacerbating device ageing. HCD thus poses a critical reliability challenge for modern metal–oxide–semiconductor field-effect transistors (MOSFETs) and tri-gate FinFETs, affecting performance consistency in high-speed logic, radio-frequency circuits and power-management systems. Understanding the interplay between HCD and other stress mechanisms—such as bias temperature instability—and developing robust predictive models are essential for ensuring the long-term operation of electronics in consumer, automotive and space applications.

Research from Nature Portfolio

Innovative on-chip thermal curing has been demonstrated as an effective route to repair hot-carrier injection damage without disrupting device operation. A flexible microwave-absorbing film applied directly to the chip surface generates uniform heat when exposed to standard microwave sources, enabling local annealing of oxide and interface traps. Studies on three-dimensional FinFET structures confirm that this approach not only reverses threshold-voltage shifts induced by hot carriers but also mitigates damage from total ionising dose, thereby extending device lifetime under harsh environments. Electrical measurements and numerical simulations reveal that microwave-induced heat treatment can be tailored to specific device topologies, offering a low-cost, in situ reliability enhancement compatible with existing fabrication flows.

Hot Carrier Degradation in Semiconductor Devices publication trend

The graph below shows the total number of articles in hot carrier degradation in semiconductor devices across all publications each year (not limited to Nature Index journals).

Technical terms

Hot Carrier Degradation (HCD): Performance deterioration resulting from high-energy carriers inducing traps in dielectric or at interfaces.

MOSFET: Metal–Oxide–Semiconductor Field-Effect Transistor, a core building block of digital and analogue electronics.

FinFET: A three-dimensional transistor architecture that uses a fin-shaped channel for improved gate control.

Flicker Noise: Low-frequency electrical noise (1/f noise) caused by carrier trapping and detrapping at defects.

Oxide Trap: A defect within the gate dielectric that can capture and release charge carriers, altering device thresholds.

Interface Trap: A defect at the semiconductor–dielectric boundary that exchanges charge with the transistor channel.

Impact Ionisation: The process by which energetic carriers generate additional electron–hole pairs, contributing to trap formation.

References

1. On-Chip Curing by Microwave for Long Term Usage of Electronic Devices in Harsh Environments. Scientific Reports (2018).
2. A Coupling Mechanism between Flicker Noise and Hot Carrier Degradations in FinFETs. Nanomaterials (2023).
3. Compact Physics Hot-Carrier Degradation Model Valid over a Wide Bias Range. Micromachines (2023).
4. Hot-Carrier Damage in N-Channel EDMOS Used in Single Photon Avalanche Diode Cell through Quasi-Static Modeling. Micromachines (2024).