Structural changes induced by helium ion irradiation in silicon carbide crystals
Structural changes induced by helium ion irradiation in silicon carbide crystals
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氦离子辐照引起碳化硅晶体的结构变化
DOI：
10.1016/0022-3115(85)90241-7
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
K. Izui
中科院分区：
文献类型：
--
作者：
K. Hojou;K. Izui
用电子显微镜观察了30 keV He离子辐照多晶SiC晶体中的缺陷结构，辐照剂量从10 14到10 17 ions/cm 2。观察到许多缺陷簇，当从c轴方向观察时，其形状为六边形，但当从平行于c平面的方向观察时，其形状为线状。这些团簇的密度随着辐照能量密度的增加而增加，并且被认为是由辐照产生的点缺陷或注入的氦原子在c-平面上的聚集形成的。当能量超过7× 1015 ions/cm 2（相当于30 keV氦离子以随机取向入射到SiC晶体上约1dpa）时，观察到了非晶化现象。这种临界能量密度的辐照不能引起离子通道方向的非晶化。在1000 K的高温下的重辐照导致了一些细小的微晶，即再结晶区。
Electron microscopic observations were performed on defect structures in polycrystalline SiC crystals irradiated with 30 keV He ions to fluences from 10 14 to 10 17 ions/cm 2. A number of defect clusters were observed which were hexagonal in shape when observed from the c-axis direction but were seen to be of linear form when viewed from a direction parallel to the c-plane. These clusters increased in density with increasing irradiation fluence, and were considered to be formed by the agglomeration of irradiation-produced point defects or the injected helium atoms on the c-planes. Amorphization was observed for a fluence above a critical value of 7× 10 15 ions/cm 2 which corresponds to about one dpa for the 30 keV helium ions incident at random orientations on a SiC crystal. Irradiations of this critical fluence were unable to cause amorphization in the ion channeling directions. Heavy irradiations at the high temperature of 1000 K resulted in a number of fine crystallites, that is, recrystallized zones.