在Ti:Al薄膜中的离子束混合研究

Investigation of ion-beam mixing in Ti:Al bilayered samples

用100keVAr^+离子在低温下对TI:Al薄膜进行了离子束混合研究。实验试样是在单晶硅上蒸镀约500nm厚的铝腹,相继再蒸上所需不同厚度的钛膜,Ar^+离子注入剂量为1.2×10^(16)—1.4×10^(17)Ar^+/cm^2。用2.0MeVa粒子对注入前后的样品进行了背散射(RBS)分析。发现铝谱前沿和钛谱后沿有明显的展宽,且随剂量的增大而加宽,Ti:Al界面原子混合扩展量的平方(σ~2)与注入剂量(φ)成线性关系;在相同注入条件下,σ~2随钛膜厚度的变化有一定的规律;界面的氧化层对原子混合有一定影响;用蒙特卡罗法进行了模拟计算,并对实验结果进行了讨论。

Ion beam mixing in thin bilayered samples of Ti:Al by 100 keV argon ions at low temperature has been studied. The samples were prepared by sequential e-beam evaporation of about 500 nm of aluminium and a layer of titanium with different thickness onto single craystals of Si .The samples were bombarded with ion doses ranging from 1.2×1016 to 1.4×1017 ions/cm2 and analysed by RBS using a 2 MeV 4He beam.It is discovered that the mixing has caused broadening of the aluminium front edge and the titanium back edge in the RBS spectrum and the interfacial broadening increases clearly with ion doses. The mixing broadening of the Ti:Al interface has a square-root dependence on argon fluence; under the same bombardment conditions the square of mixing broadening is related to the thickness of the Ti layer. It is found that mixing is influenced by the presence of the interfacial oxide layer between the titanium and aluminium layers. The experimental results are compared with Monte Carlo computer simulations and the mixing process is discussed in derail.