Pulse number controlled laser annealing for GeSn on insulator structure with high substitutional Sn concentration
Pulse number controlled laser annealing for GeSn on insulator structure with high substitutional Sn concentration
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DOI：
10.1063/1.4955059
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发表时间：
2016-07
影响因子：
4
通讯作者：
K. Moto;R. Matsumura;T. Sadoh;H. Ikenoue;M. Miyao
中科院分区：
文献类型：
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作者：
K. Moto;R. Matsumura;T. Sadoh;H. Ikenoue;M. Miyao
对于实现高速薄膜晶体管和高效率光学器件来说，具有较高的锡浓度(>；8%)的晶体绝缘体结构(>；8%)超过了锡在锗中的热平衡固溶度(∼2%)。利用脉冲激光退火法研究了Ge1−xSnx(0≤x≤0.2)在石英衬底上的非热平衡生长。通过在Ge中掺入5%以上的锡，可以在不烧蚀薄膜的情况下实现完全晶化的激光通量窗口急剧扩大(∼5倍)。随着辐照脉冲数的减少，生长层中的替位锡浓度增加。这一现象可以用更快的冷却速度和更低的脉冲数实现显著的热非平衡生长解释。结果表明，对于初始锡浓度为15%的样品，在单次脉冲辐照下，获得了替位锡浓度为∼12%的GeSn单晶。拉曼光谱和电子显微镜..。
Crystalline GeSn-on-insulator structures with high Sn concentration (>8%), which exceeds thermal equilibrium solid-solubility (∼2%) of Sn in Ge, are essential to achieve high-speed thin film transistors and high-efficiency optical devices. We investigate non-thermal equilibrium growth of Ge1−xSnx (0 ≤ x ≤ 0.2) on quartz substrates by using pulsed laser annealing (PLA). The window of laser fluence enabling complete crystallization without film ablation is drastically expanded (∼5 times) by Sn doping above 5% into Ge. Substitutional Sn concentration in grown layers is found to be increased with decreasing irradiation pulse number. This phenomenon can be explained on the basis of significant thermal non-equilibrium growth achieved by higher cooling rate after PLA with a lower pulse number. As a result, GeSn crystals with substitutional Sn concentration of ∼12% are realized at pulse irradiation of single shot for the samples with the initial Sn concentration of 15%. Raman spectroscopy and electron microscopy ...