Self-limiting growth when using trimethyl bismuth (TMBi) in the metal-organic vapor phase epitaxy (MOVPE) of GaAs1-yBiy
Self-limiting growth when using trimethyl bismuth (TMBi) in the metal-organic vapor phase epitaxy (MOVPE) of GaAs1-yBiy
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DOI：
10.1016/j.jcrysgro.2014.03.014
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发表时间：
2014-06-01
影响因子：
1.8
通讯作者：
Kuech, Thomas F.
中科院分区：
文献类型：
--
作者：
Forghani, Kamran;Guan, Yingxin;Kuech, Thomas F.
理论和实验研究已经证实，GaAs 1-yBiy半导体合金系统具有用于长波长应用的潜力，并且与在类似波长下发射的其他材料相比，器件具有改进的性能。通过金属有机气相外延（MOVPE）生长GaAs 1-yBiy仍然是一个挑战;由于As和Bi之间的电负性和共价半径的巨大差异，铋不容易并入GaAs基质中。这些差异通常会导致Bi表面偏析或Bi在GaAs基质中的掺入率非常低。我们研究了以三甲基铋为铋源生长GaAs、Bi量子阱结构。随着进入生长反应器的Bi前体流量的增加，观察到生长速率降低。另外，在非常低的生长温度下含Bi层的生长时间的增加不会导致层厚度的相应增加，这表明接近自限性生长。复杂的成分配置文件推导出生结合X射线衍射分析与透射电子显微镜调查被用来开发的GaAs 1-yBiy异质结构，其中包括一个复杂的相互作用的化学表面物种的MOVPE生长的唯象模型。甲基封端的表面的存在下，与使用三甲基铋，特别是在低生长温度下，导致有效的“现场封锁”的Bi前体抑制生长的GaAs 1-yBiy异质结构。(C)2014爱思唯尔有限公司版权所有。
Theoretical and experimental studies have confirmed that the GaAs1-yBiy semiconductor alloy system has potential for long wavelength applications and devices with improved performance over other materials emitting at similar wavelengths. The growth of GaAs1-yBiy by metal organic vapor phase epitaxy (MOVPE) remains a challenge; bismuth is not easily incorporated into the GaAs matrix due the large difference in electronegativity and covalent radii between As and Bi. These differences often lead to Bi surface segregation or very low incorporation rates of Bi into the GaAs matrix. We have studied the growth of GaAs, Bi, quantum well structures using trimethyl bismuth as the Bi source. A reduced growth rate is observed with increasing Bi precursor flux into the growth reactor. Additionally, an increase in the growth time for the Bi-containing layer at very low growth temperatures does not lead to a corresponding increase in layer thickness, which is indicative of a near self-limiting growth. Complex compositional profiles deduced born combining x-ray diffraction analysis with the transmission electron microscopy investigations are used to develop a phenomenological model of the MOVPE growth of GaAs1-yBiy heterostructures which includes a complex interplay of the chemical surface species. The presence of a methyl-terminated surface, associated with the use of trimethyl Bi, particularly at low growth temperatures, leads to an effective "site blocking" by Bi precursor inhibiting the growth of GaAs1-yBiy hetero-structures. (C) 2014 Elsevier B.V. All rights reserved.