arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2009.05957cond-mat.mtrl-sci
收藏

通过脉冲laser和溅射沉积生长Sb2Te3的差异

Differences in Sb2Te3 growth by pulsed laser and sputter deposition

Jing Ning, J. C. Martinez, Jamo Momand, Heng Zhang, Subodh C. Tiwari, Fuyuki Shimojo, Aiichiro Nakano, Rajiv K. Kalia, Priya Vashishta, Paulo S. Branicio, Bart … 展开作者

Jing Ning, J. C. Martinez, Jamo Momand, Heng Zhang, Subodh C. Tiwari, Fuyuki Shimojo, Aiichiro Nakano, Rajiv K. Kalia, Priya Vashishta, Paulo S. Branicio, Bart J. Kooi, Robert E. Simpson

摘要:

高质量的范德瓦耳斯硫族化合物在相变数据存储、热电和自旋电子学中是重要的。利用统计实验设计和密度泛函理论相结合的方法,我们阐明了非平衡范德华外延沉积方法是如何提高Sb 2 Te 3薄膜的晶体质量的。我们比较了射频溅射和脉冲激光沉积(PLD)生长的薄膜。每种方法影响晶体质量的生长因素是不同的。对于PLD生长的薄膜,薄的非晶Sb_2Te_3籽晶层最显着地影响晶体质量。相比之下,通过溅射生长的膜的结晶质量对沉积温度相当敏感,并且受种子层的存在的影响较小。这种差异有些令人惊讶,因为这两种方法都是基于热平衡等离子体的方法。非绝热量子分子动力学模拟表明,这种差异源于等离子体中激发原子的密度。PLD等离子体比溅射中使用的等离子体更强烈并且具有更高的能量,并且这增加了沉积原子的电子温度,这伴随地增加了PLD中的吸附原子扩散长度。与此相反,吸附原子的扩散率主要由溅射生长的薄膜的热温度。这些结果解释了文献中观察到的Sb2Te3和超晶格晶体质量的宽范围。这些结果表明,与流行的看法相反,基于等离子体的沉积方法适合于生长高质量的晶体硫属化物。

英文摘要:

High quality Van der Waals chalcogenides are important for phase change data storage, thermoelectrics, and spintronics. Using a combination of statistical design of experiments and density functional theory, we clarify how the out-of-equilibrium van der Waals epitaxial deposition methods can improve the crystal quality of Sb2Te3 films. We compare films grown by radio frequency sputtering and pulsed laser deposition (PLD). The growth factors that influence the crystal quality for each method are different. For PLD grown films a thin amorphous Sb2Te3 seed layer most significantly influences the crystal quality. In contrast, the crystalline quality of films grown by sputtering is rather sensitive to the deposition temperature and less affected by the presence of a seed layer. This difference is somewhat surprising as both methods are out-of-thermal-equilibrium plasma-based methods. Non-adiabatic quantum molecular dynamics simulations show that this difference originates from the density of excited atoms in the plasma. The PLD plasma is more intense and with higher energy than that used in sputtering, and this increases the electronic temperature of the deposited atoms, which concomitantly increases the adatom diffusion lengths in PLD. In contrast, the adatom diffusivity is dominated by the thermal temperature for sputter grown films. These results explain the wide range of Sb2Te3 and superlattice crystal qualities observed in the literature. These results indicate that, contrary to popular belief, plasma-based deposition methods are suitable for growing high quality crystalline chalcogenides.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑