Ga-induced superstructures on the Si(1 1 1) 7 × 7 surface
Ga-induced superstructures on the Si(1 1 1) 7 × 7 surface
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DOI：
10.1016/j.apsusc.2009.07.036
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发表时间：
2009-10
影响因子：
6.7
通讯作者：
Praveen Kumar;Mahesh Kumar;B. Mehta;S. M. Shivaprasad
中科院分区：
文献类型：
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作者：
Praveen Kumar;Mahesh Kumar;B. Mehta;S. M. Shivaprasad
研究了Ga在Si表面的单层吸附，目的是形成p-δ掺杂纳米结构。Si表面Ga相可以通过N ~（2+）离子轰击氮化，形成具有电子约束特性的GaN纳米结构，用于新型光电器件。在本研究中，我们报道了在室温下，在可控的超真空条件下，Ga在7×7重构Si（111）表面上的亚单层吸附。我们使用原位俄歇电子能谱、电子能量损失谱和低能电子衍射来监测生长和确定性质。我们观察到，Ga生长在Stranski-Krastanov生长模式，岛开始形成两个平面单层。通过监测Si（LVV）线的形状，在界面演化过程中观察到的悬挂键密度的变化。Ga吸附系统进行热退火和剩余热脱附研究。在表面形态上的吸附动力学和脱附动力学的差异解释在应变弛豫路线和键合配置。由于存在一个充满活力的层次结构的居住网站的吸附原子，网站，我们还绘制了一个二维相图，由几个表面相。我们的EELS结果表明，表面相的电子性质对其各自的结构排列是独特的。
Monolayer Ga adsorption on Si surfaces has been studied with the aim of forming p-delta doped nanostructures. Ga surface phases on Si can be nitrided by N2+ion bombardment to form GaN nanostructures with exotic electron confinement properties for novel optoelectronic devices. In this study, we report the adsorption of Ga in the submonolayer regime on 7×7 reconstructed Si(111) surface at room temperature, under controlled ultrahigh vacuum conditions. We use in-situ Auger electron spectroscopy, electron energy loss spectroscopy and low energy electron diffraction to monitor the growth and determine the properties. We observe that Ga grows in the Stranski-Krastanov growth mode, where islands begin to form on two flat monolayers. The variation in the dangling bond density is observed during the interface evolution by monitoring the Si (LVV) line shape. The Ga adsorbed system is subjected to thermal annealing and the residual thermal desorption studied. The difference in the adsorption kinetics and desorption dynamics on the surface morphology is explained in terms of strain relaxation routes and bonding configurations. Due to the presence of an energetic hierarchy of residence sites of adatoms, site we also plot a 2D phase diagram consisting of several surface phases. Our EELS results show that the electronic properties of the surface phases are unique to their respective structural arrangement.