Ion track effect on point defect production in SiC
Ion track effect on point defect production in SiC
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DOI：
10.1080/10420150.2011.569718
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发表时间：
2011-04
影响因子：
1
通讯作者：
G. Litrico;M. Zimbone;P. Musumeci;L. Calcagno;G. Foti
中科院分区：
文献类型：
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作者：
G. Litrico;M. Zimbone;P. Musumeci;L. Calcagno;G. Foti
采用低温（40 K）光致发光（PL）测量方法研究了200 keV H+和800 keV C+在5×109 ~ 3.5×1012 ions/cm ~ 2能量范围内辐照4 H-SiC外延层引起的缺陷形成。辐照后，由于激子在离子束诱导的结构缺陷处的复合，在425-443 nm波长范围内形成了一些尖锐的谱线，称为“字母线”。发光线强度与离子注量的分析使我们能够标记两组不同的峰，即P1组（e、f和g线）和P2组（a、B、c和d线）。P1群谱线的归一化产额随着离子注量的增加而增加，并达到最大值，而P2群谱线的归一化产额呈现出阈值注量，然后增加，直到达到饱和值。这些不同的趋势表明，虽然P1群线与离子束产生的主要缺陷（间隙缺陷、空位）有关，但P2群线可能与一些复杂缺陷（双空位、反位）有关。用H+和C+离子辐照的趋势相似;然而，缺陷形成发生在C+辐照的5×109-1011离子/cm 2和H+辐照的1011-4×1012离子/cm 2的注量范围内。考虑到在弹性碰撞中沉积的能量的不同值，依赖于离子类型被发现：C+离子的结果是在缺陷生产的效率较低，因为更高的缺陷重组发生在其密集的级联。
Low-temperature (40 K) photoluminescence (PL) measurements were used to follow the defect formation induced in the 4H-SiC epitaxial layer by irradiation with 200 keV H+ and 800 keV C+ in the fluence range of 5×109–3.5×1012 ions/cm2. After irradiation, the PL spectra show the formation of some sharp lines, called “alphabet lines”, located in the wavelength range of 425–443 nm, due to the recombination of excitons at structural defects induced by ion beams. The analysis of luminescence line intensity versus ion fluence allows us to mark two different groups of peaks, namely the P1 group (e, f and g lines) and the P2 group (a, b, c and d lines). The normalised yield of P1 group lines increases with ion fluence and reaches a maximum value, while the normalised yield of P2 group lines exhibits a threshold fluence and then increases until a saturation value is reached. These different trends indicate that, while the P1 group lines are related to the primary defects created by ion beams (interstitial defects, vacancies), the P2 group lines can be associated with some complex defects (divacancy, antisites). The trends are similar for irradiation with H+ and C+ ions; however, the defect formation occurs in the fluence range of 5×109–1011 ions/cm2 for C+ irradiation and 1011–4×1012 ions/cm2 for H+ irradiation. Taking into account the different values of energy deposited in elastic collision, a dependence on the ion type was found: the C+ ion results in being less effective in defect production as a higher defect recombination occurs inside its dense cascade.