论文标题
在MBE生长的GESN的原位掺杂过程中，表面活性剂行为和有限掺入im
Surfactant behavior and limited incorporation of Indium during in-situ doping of GeSn grown by MBE
论文作者
论文摘要
GESN是一种有前途的IV组半导体材料，用于芯片SI光子型设备和高弹性晶体管。这些设备需要使用掺杂的GESN区域，最好在外交期间获得原位。从电子价的角度来看，IV组材料的P型掺杂剂包括B，AL，GA和IN。后一种元素从未被研究为GESN中的P型掺杂剂。在这项工作中，我们探索了MBE种植的GESN的P型GESN的原位。我们证明，在GESN的外延生长期间作为表面活性剂的作用：在表面积累并以移动sn-in液滴的形式诱导隔离，从而强烈影响材料的局部组成。在非缺陷的GESN中，我们测量了2.8e18cm-3的最大掺入，这比文献中报道的GESN的原位P型掺杂的值低两个数量级。我们进一步表明，在低生长温度下诱导缺陷的成核，阻碍了平衡外生长过程，从而最大化掺杂剂的掺入。这项工作提供了有关与GESN掺杂相关的原位限制的见解，并劝阻其在基于GESN的光电设备中的利用。
GeSn is a promising group-IV semiconductor material for on-chip Si photonics devices and high-mobility transistors. These devices require the use of doped GeSn regions, achieved preferably in-situ during epitaxy. From the electronic valence point of view, p-type dopants of group-IV materials include B, Al, Ga and In. The latter element has never been investigated as p-type dopant in GeSn. In this work, we explore in-situ In p-type doping of GeSn grown by MBE. We demonstrate that In acts as a surfactant during epitaxial growth of GeSn:In, accumulating on surface and inducing segregation in the form of mobile Sn-In liquid droplets, strongly affecting the local composition of the material. In non-defective GeSn, we measure a maximal In incorporation of 2.8E18cm-3, which is two orders of magnitude lower than the values reported in the literature for in-situ p-type doping of GeSn. We further show that In induces the nucleation of defects at low growth temperatures, hindering out-of-equilibrium growth processes for maximization of dopant incorporation. This work provides insights on the limitations associated with in-situ In doping of GeSn, and discourages its utilization in GeSn-based optoelectronic devices.
