Kim S H, Lee B K, Baik J, Jeon C, Lee S S, Lee J, Hwang H N, Hwang C C, Park C Y, An K S
Device Materials Research Center, Advanced Materials Division, Korea Research Institute of Chemical Technology, Yuseong, PO Box 107, Daejeon 305-600, Korea.
J Nanosci Nanotechnol. 2011 May;11(5):4328-32. doi: 10.1166/jnn.2011.3629.
In-situ synchrotron radiation photoemission spectroscopy and X-ray photoemission spectroscopy have been used to investigate the initial stages of Al2O3 growth on a Si(001) substrate by atomic layer deposition (ALD). The core level spectra of Si 2p, O 1s, and Al 2p as well as the valence band spectra were measured at every half reaction in the trimethylaluminum (TMA)-H2O ALD process. The line shape changes and binding energy shifts of the core level spectra reveal that Al2O3 is predominantly formed with a small amount of Si oxide in the initial stages without the formation of Al silicate. All core level spectra were alternately shifted toward higher and lower binding energies sides at every half ALD reaction. This can be explained by the band bending effect induced by different chemical species on the surface during the TMA-H2O ALD reaction. The valence band spectra showed that four cycles of ALD reactions were necessary to complete the electronic structure of the Al2O3 film with a valence band offset of 3.73 eV.
原位同步辐射光电子能谱和X射线光电子能谱已被用于通过原子层沉积（ALD）研究在Si(001)衬底上Al2O3生长的初始阶段。在三甲基铝（TMA）-H2O原子层沉积过程的每半个反应中，测量了Si 2p、O 1s和Al 2p的芯能级谱以及价带谱。芯能级谱的线形变化和结合能位移表明，在初始阶段Al2O3主要形成，伴有少量的硅氧化物，没有形成铝硅酸盐。在每半个原子层沉积反应中，所有芯能级谱交替地向更高和更低结合能侧移动。这可以通过TMA-H2O原子层沉积反应期间表面上不同化学物种引起的能带弯曲效应来解释。价带谱表明，需要四个原子层沉积反应循环来完成具有3.73 eV价带偏移的Al2O3薄膜的电子结构。
