Recrystallization Kinetics of 3C Silicon Carbide Implanted with 400 keV Cesium Ions

Abstract

Polycrystalline 3C silicon carbide (SiC) was implanted at room temperature with 400 keV cesium ions to a dose of 1016 ions/cm2. The samples were annealed at 600°C–1000°C for times up to 48 h to observe changes in the implantation zone crystallinity and density. The implanted regions were characterized by transmission electron microscopy (TEM) and secondary ion mass spectroscopy (SIMS) before and after annealing. It is shown that the implantation resulted in a 217 ± 2 nm amorphous region with microstructural damage extending to ~250 nm below the surface. Recrystallization of the amorphous region was observed to begin at 725°C. Densification was determined indirectly through changes in the measured implantation zone thickness. Measurable thickness, or densification, of the implanted region was not observed until temperatures greater than ~800°C. The SiC recrystallization began at the interface between the amorphous, damaged region, and the underlying polycrystalline material. Image analysis was used to quantify the fraction of crystalline phase as a function of time and temperature. The recrystallization kinetics exhibited Arrhenius dependency with an apparent activation energy of 480 kJ/mol. SIMS demonstrated that 60%–70% of the cesium was retained within the recrystallized microstructure after thermal annealing.

Imprinting the Polytype Structure of Silicon Carbide by Rapid Thermal Processing

“…The activation energy of the recrystallization process scatters between 2.1 and 8.9 eV depending on the amorphous material and the substrate. For silicon and silicon carbide substrates for deposited amorphous SiC [113,114] and amorphized by ion implantation SiC [116], the activation energy of the crystallization process was found to be in a narrow range between 4.9 and 5.1 eV. The only exception is [117], where an activation energy of 2.1 eV was found based on the investigation of the step height evolution of ion-implanted 6H-SiC substrates during annealing.…”

“…The crystallization kinetics of deposited amorphous and amorphized by ion implantation silicon carbide was studied in [112][113][114][115][116][117]. The activation energy of the recrystallization process scatters between 2.1 and 8.9 eV depending on the amorphous material and the substrate.…”

Effect of swift heavy ions irradiation in the migration of silver implanted into polycrystalline SiC

“…As mentioned above and extensively reviewed in [3], high fluence (~ 10 16 cm -2 ) ion bombardment at room temperature causes amorphization of the implanted layer in SiC, either in single crystalline or polycrystalline SiC. Recrystallization into a polycrystalline structure starts to occur after annealing at 800 °C [3,33]. One of the advantages of SiC is its radiation hardness at elevated temperatures, that is, it cannot be amorphized by ion bombardment at substrate temperatures above 350 °C and remains crystalline [34].…”

Irradiation-induced β to α SiC transformation at low temperature

“…Composites and liquid-phase sintered SiC are both strong candidates for accident-tolerant light-water reactor fuel cladding or matrices 9 , 16 , 17 , as a response to the detrimental properties of the present zirconium-alloy fuels demonstrated by the Fukushima disaster, although hydrothermal corrosion may be a limiting factor 18 – 22 . SiC is also an important high-temperature/high-power semiconductor 4 , 23 , and ion implantation (and its associated damage) is important for device fabrication.…”