Interface chemistry and surface morphology evolution study for InAs/Al2O3 stacks upon in situ ultrahigh vacuum annealing

• Published in: Applied surface science Vol. 443; pp. 567 - 574
• Main Authors: Wang, Xinglu, Qin, Xiaoye, Wang, Wen, Liu, Yue, Shi, Xiaoran, Sun, Yong, Liu, Chen, Zhao, Jiali, Zhang, Guanhua, Liu, Hui, Cho, Kyeongjae, Wu, Rui, Wang, Jiaou, Zhang, Sen, Wallace, Robert M., Dong, Hong
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.06.2018
• Subjects: Elemental diffusion; High-k dielectrics; InAs; Surface morphology; Thermal stability; Elemental diffusion; High-k dielectrics; InAs; Surface morphology; Thermal stability
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2018.03.009

[Display omitted] •The elemental diffusion and desorption are detected for InAs/Al2O3 stacks.•Bubbles and pits on the InAs/Al2O3 surface are detected after PDA in UHV.•This work highlights the importance of interface passivation for InAs/Al2O3 stack. A systematic study of the interfacial chemistry for the HCl pretreated and native oxide InAs(100) samples upon atomic layer deposition (ALD) of Al2O3, and the post deposition annealing (PDA) process has been carried out, using in situ synchrotron radiation photoelectron spectroscopy. The “clean up” effect for the native oxide sample is detected, but it is not observed for the HCl pretreated sample. The out-diffusion and desorption of both In and As oxides have been characterized during the ALD process and the following PDA process. The surface morphology evolution during the PDA process is studied by in situ photo-emission electron microscopy. The bubbles emerged after PDA at 360 °C and grew up at 370 °C. After PDA at 400 °C and at higher temperatures, pits are seen in some areas, and the tear up of the Al2O3 film is seen in other areas with the formation of indium droplets. This study gives insight in the mechanism of elemental diffusion/desorption, which may associate the reliability of III-V semiconductor based devices.