Wide bandgap semiconductors have emerged as game-changers across numerous industries, offering a sea of advantages that make them invaluable in today's technology-driven world. One of their key attributes is their exceptional high-temperature tolerance. Materials like silicon carbide and gallium nitride can withstand extreme heat, allowing them to thrive in applications where traditional silicon-based semiconductors would fail miserably. This quality is especially crucial in industries like aerospace and automotive, where temperature variations can be severe. Wide bandgap semiconductors empower these sectors to develop robust and reliable electronic systems capable of operating in the most challenging environments.

Furthermore, wide bandgap semiconductors are renowned for their ability to handle high voltages and provide superior power conversion efficiency. Their ability to rapidly switch between on and off makes them the best suited for high-frequency applications, such as radar systems and RF communication. Moreover, their reduced susceptibility to radiation damage opens doors to applications in space, nuclear, and defense industries, while also contributing to their longer lifespan. Overall, wide bandgap semiconductors are driving innovation and transforming industries by delivering enhanced performance, smaller footprints, and improved environmental sustainability.

However, wideband semiconductors like SiC are more susceptible to radiation damage which affects their ability to sustain in space galactic cosmic ray environment conditions, moreover, these semiconductors experience single-event effects and single-event burnout under radiation. The two main modes of failure in wide bandgap semiconductors due to radiation are Total dose failure and Single event upset, which are unique and cause damage to the data aboard the semiconductor or cause defect cluster, structural damage, dislocation cluster loops, and vacancies. The mode of radiation damage inflicted on the semiconductor is crucial as well, as newer generations of devices are extremely small in size and a single high energy ion or a single gamma ray is more than enough to cause a single event failure which can potentially flip a bit from 0 to 1.

Ⅰ. A Brief Investigation in Radiation Damage and Potential Materials That Can be Used to Avoid it.

Radiation damage is one of the most prominent causes of failure in WBG semiconductors causing structural defects and data loss, therefore it is important to understand the damage processes and how different materials are affected by it. In addition to defects related to growth processes, radiation-induced flaws in materials arise from electronic effects, including ionization, charge transfer, and nuclear displacement damage. Furthermore, insulators used in gate voltage applications for transistor structures may also experience damage. High-energy particles and electromagnetic radiation, like lasers and X-rays, impart inelastic linear energy transfer to the electronic structure, leading to the generation of energetic electrons which in turn results in ionization and excitation. These electrons initially dissipate their energy through a sequence of electron-electron energy transfers, leading to the creation of electron-hole pairs in a very short timescale. Subsequently, much of this energy is transferred to the atomic structure through electron-phonon coupling, inducing localized thermal spikes on a timescale of less than 300 femtoseconds. Finally, this process also gives rise to localized electronic excitations that can potentially disrupt or alter ionic or covalent bonds, increase defect and atomic mobilities, and elevate the overall system energy level.

As ions penetrate the material during irradiation, they primarily lose energy through electronic stopping and follow straight trajectories. However, for exceptionally light ions like hydrogen and helium, sporadic nuclear collisions with heavier target atoms can lead to more random. As the ion's energy decreases, the probability of collisions with nuclei increases, eventually becoming the dominant energy-dissipation mechanism. When atoms receive substantial recoil energies, they are removed from their lattice positions, triggering a sequence of further lattice collisions. These collision floods are the primary culprits behind damage generation.

Ions predominantly create point defects, which typically emerge immediately after irradiation. The final phase of irradiation typically involves interactions between multiple atoms. This is a result of both nuclear and electronic stopping, causing high-energy ions and recoils to decelerate until they reach thermal velocities, which are below 1 electron volt. During this stage, they collide with multiple atoms simultaneously, a phenomenon known as many-body collisions. On the other hand, a thermal defect recombination takes place when atoms return to their peak crystalline state, resulting in no lattice damage. The efficient recombination of displaced atoms is significantly influenced by the irradiation temperature and is also strongly dependent on the semiconductor's bandgap and the nature of its atomic bonding.

The current state-of-the-art materials as shown in Figure 1 have been developed in order to develop a resistance against radiation damage.

Figure 1 Crucial Parameters of Different Wide Bandgap Semiconductors.

It is clearly seen that the new materials developed have significantly higher electric breakdown fields when compared to traditional Si semiconductors, which enables them to have thinner layers, better voltage-blocking capabilities and higher doping concentration. Moreover, these newly developed materials are suited for different applications respectively as depicted in Figure 2.

Figure 2 Spider Diagram of Varying Ultra-Wide Bandgap and Wide Bandgap Materials Feasible for Different Applications.

Ⅱ. Conclusion

Radiation damage stands as a prominent threat to the integrity and functionality of Wide Bandgap semiconductors, leading to structural defects and potential data loss. To address this concern effectively, understanding the details of damage processes and their differential impact on various materials is essential. The rise of radiation-induced defects involves a complex network of electronic effects, including ionization, charge transfer, and nuclear displacement damage. High-energy particles and electromagnetic radiation induce electron excitation, resulting in the formation of electron-hole pairs within an extremely short timeframe. Subsequently, energy dissipates into the atomic structure, generating localized thermal spikes and electronic excitations that can disrupt atomic bonds and elevate system energy levels, resulting in the failure of the semiconductor. On the other hand, newly developed wideband gap and ultra-wide bandgap materials showed impressive resilience to radiation damage mostly because of heightened electric field and responsiveness to radiation hardening when compared to traditional Si-based semiconductors.

To mitigate radiation damage in Wide Bandgap semiconductors, several practices and strategies are being employed. These include the development of radiation-hardened semiconductor materials and designs tailored to withstand radiation exposure. Advanced material engineering, including the incorporation of radiation-tolerant substrates, can significantly reduce the susceptibility of WBG semiconductors to radiation-induced defects. Additionally, the application of protective coatings, such as radiation-resistant encapsulation materials, can shield semiconductor components from radiation damage.