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高电荷态离子比普通的离子携带较高的势能,势能在材料表面的瞬间释放,能在材料表面形成nm量级的结构损伤。它在纳米刻蚀、小型纳米器件、纳米材料、超小尺寸半导体芯片制作、固体表面处理和固体结构分析等领域具有广泛应用前景。因此对高电荷态重离子(Xeq+)引起半导体材料表面(6H-SiC)纳米结构变形进行了研究。采用Xe18+和Xe26+离子,选取从1×1014到5×1015 ions·cm-2逐渐递增的剂量,以垂直和倾斜60°角两种入射方式辐照6H-SiC薄膜样品,经原子力显微镜分析表明,辐照后的表面肿胀凸起。对于Xe18+离子辐照的样品,辐照区至未辐照区边界的台阶高度随离子剂量增加而连续增大,而对于Xe26+离子辐照的样品则先增加而后减小。在相同入射角和剂量条件下,Xe26+离子辐照样品形成的台阶高度大于Xe18+离子辐照形成的台阶高度,在相同离子和剂量的条件下,垂直照射时形成的台阶高度大于倾斜照射时形成的台阶高度。根据损伤机理和实验数据,首次初步建立了一个包括势能、电荷态、入射角和剂量等物理量的理论模型来预测高电荷态离子在半导体材料表面形成的纳米结构变形。暗示了高电荷态离子的潜在的应用价值及进一步研究的必要性。
Highly charged ions carry higher potential energy than ordinary ions. The potential energy is released instantly at the surface of the material, which can form structural damage of the order of nm on the surface of the material. It has a wide range of applications in the fields of nanolithography, small nanodevices, nanomaterials, ultra-small size semiconductor chip fabrication, solid surface treatment and solid structure analysis. Therefore, the deformation of the surface of the semiconductor material (6H-SiC) nanostructures caused by highly charged heavy ions (Xeq +) has been studied. Using Xe18 + and Xe26 + ions, a gradually increasing dose from 1 × 1014 to 5 × 1015 ions · cm-2 was selected and the 6H-SiC films were irradiated at both vertical and oblique angles of incidence. The atomic force microscopy analysis showed that, Irradiated surface swelling bulge. For Xe18 + ion-irradiated samples, the height of the step from the irradiated area to the boundary of the unirradiated area continuously increases with the increase of ion dose, while the sample irradiated with Xe26 + ion first increases and then decreases. Under the same incident angle and dose conditions, the height of step formed by Xe26 + ion irradiation was larger than the step height formed by Xe18 + ion irradiation. Under the same ion and dose conditions, the height of step formed by vertical irradiation was larger than that formed by oblique irradiation Step height. According to the damage mechanism and experimental data, a theoretical model including the physical quantities such as potential energy, charge state, incident angle and dose is established for the first time to predict the deformation of nanostructures formed on the surface of semiconductor materials by highly charged ions. The potential applications of highly charged ions and the need for further research are suggested.