Displacement damage and total ionisation dose effects on 4H‐SiC power devices

Abstract

A comprehensive study of displacement damage and total ionisation dose effects on 4H-silicon carbide power devices is presented. Power diodes and transistors produced by different manufacturers were irradiated by high-energy particles (protons, alphas, electrons and neutrons). The influence of radiation on device characteristics was determined, the introduced radiation defects were identified, and the main degradation mechanisms were established. Results show that radiation leads to the creation of acceptor traps in the lightly doped drift regions of irradiated devices. Devices then degrade due to the removal of the carriers and the decrease in carrier mobility and lifetime. For unipolar devices, the gradual increase of the forward voltage is typical while the blocking characteristics remain nearly unchanged. In bipolar devices, high introduction rates of defects cause a sharp reduction of carrier lifetime. This results in shorter carrier diffusion lengths and subsequent loss of conductivity modulation leading to a sharp increase of the forward voltage drop. The irradiation also shifts the threshold voltage of power switches. That is critical, namely for metal-oxide-semiconductor field-effect transistors. According to the authors' study, the junction barrier Schottky diode and junction field-effect transistor (JFET) can be considered the most radiation-resistant SiC power devices.

Radiation Hardness of Silicon Carbide upon High-Temperature Electron and Proton Irradiation

“…The effect of room temperature electron irradiation on the properties of high-voltage 4H-SiC Schottky diodes also has been studied in many works [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. The effect of room-temperature proton irradiation on the properties of 4H-SiC JBS has been extensively studied [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. Consequently, in this work, we considered it expedient to focus on the results of our work in the field of high-temperature irradiation.…”

On the Suitability of 3C-Silicon Carbide as an Alternative to 4H-Silicon Carbide for Power Diodes

“…These traps are typically present in the bulk of 4H-SiC. Lifetime killing defects Z1/Z2 and EH6/7 have been reported as the dominant type of deep levels in as-grown SiC [62]. These centres are related to carbon vacancies (VC), and demonstrate an acceptor-like behaviour [63], [64].…”

“…Their concentration depends on the growth rate and the C/Si ratio in the gas phase during SiC epitaxy [65]. The Z1/Z2 and EH6/7 deep-lying electron traps have proven to be very stable against annealing temperatures that reach 1300°C [62]. The concentration of Z1/Z2 and EH6/7 can be further enhanced by the process of ion implantation, resulting in levels of 10 14 -10 15 cm -3 magnitude [66].…”

Corrosion of Ceramic Silicon Carbide in Hydrofluoric Acid

“…Actually, power electronics based on 4H-SiC single crystals has become a serious competitor for silicon-based components [12]. The outstanding feature of components made of silicon carbide is their high radiation resistance, which makes them suitable for the use in extreme conditions both on the Earth and in the outer space [13,14].…”