Ntshobeni G, Abdalla Z A Y, Mokgadi T F, Mlambo M, Njoroge E G, Msimanga M, Sohatsky A, Skuratov V A, Hlatshwayo T T
Physics Department, University of Pretoria, Pretoria, South Africa.
Health Platform, Advanced Materials Division, Mintek, 200 Malibongwe Drive, Randburg, South Africa.
Heliyon. 2023 Oct 10;9(10):e20877. doi: 10.1016/j.heliyon.2023.e20877. eCollection 2023 Oct.
The effects of helium (He), silver (Ag) and strontium (Sr) ions triple implanted into polycrystalline silicon carbide (SiC) were investigated. Ag ions of 360 keV were first implanted into polycrystalline SiC to a fluence of 2 × 10 cm at 600 °C, followed by implantation of Sr ions of 280 keV to a fluence of 2 × 10 cm also at 600 °C (Ag + Sr-SiC). Some of Ag + Sr-SiC samples were then implanted with 17 keV He ions to a fluence of 1 × 10 cm at 350 °C (Ag + Sr + He-SiC). Some of the dual (Ag + Sr-SiC) and triple (Ag + Sr + He-SiC) implanted samples were annealed at 1000 °C for 5 h. Both dual and triple implantation resulted in the accumulation of defects without amorphization of SiC structure. Moreover, triple implantation also resulted in formation of elongated He nano-bubbles and cavities in the damaged SiC accompanied by the appearance of blisters and craters on the surface. Healing of some structural defects was observed after annealing at 1000 °C in both dual and triple implanted samples. Implantation of Sr caused pre-implanted Ag to form precipitates indicating some limited migration while implantation of He caused some migration of both Ag and Sr. The migration of Ag was accompanied by formation of bigger precipitates trapped in He-cavities. Annealing the triple implanted caused the migration of both Ag and Sr governed by trapping of both implanted species by cavities due to some exo-diffusion of He. No migration was observed in the dual implanted samples annealed at 1000 °C. Hence, He bubbles assisted migration of implants and He cavities trap the implanted species.
研究了氦（He）、银（Ag）和锶（Sr）离子三重注入多晶硅碳化硅（SiC）的效果。首先将能量为360 keV的Ag离子在600°C下注入多晶SiC，注入剂量为2×10 cm，随后在600°C下再注入能量为280 keV的Sr离子，注入剂量也为2×10 cm（Ag + Sr - SiC）。然后，将部分Ag + Sr - SiC样品在350°C下注入能量为17 keV的He离子，注入剂量为1×10 cm（Ag + Sr + He - SiC）。部分双注入（Ag + Sr - SiC）和三注入（Ag + Sr + He - SiC）样品在1000°C下退火5小时。双注入和三注入均导致缺陷积累，但SiC结构未非晶化。此外，三注入还导致在受损的SiC中形成拉长的He纳米气泡和空洞，同时表面出现水泡和坑洼。在双注入和三注入样品中，1000°C退火后均观察到一些结构缺陷的愈合。Sr的注入导致预先注入的Ag形成沉淀，表明有一定程度的迁移，而He的注入导致Ag和Sr都发生了一些迁移。Ag的迁移伴随着在He空洞中捕获更大沉淀的形成。三注入样品退火导致Ag和Sr的迁移，这是由于He的一些外扩散，两种注入物种被空洞捕获所致。在1000°C退火的双注入样品中未观察到迁移。因此，He气泡促进了注入物的迁移，He空洞捕获了注入物种。
