Atomic-Scale Modification of Oxidation Phenomena on the Ge(100) Surface by Si Alloying

Mikhail Kuzmin; Juha-Pekka Lehtiö; Zahra Jahanshah Rad; Svetlana V Sorokina; Marko P J Punkkinen; Hannu-Pekka Hedman; Risto Punkkinen; Pekka Laukkanen; Kalevi Kokko

doi:10.1021/acsmaterialsau.1c00039

Atomic-Scale Modification of Oxidation Phenomena on the Ge(100) Surface by Si Alloying

ACS Mater Au. 2021 Dec 16;2(2):204-214. doi: 10.1021/acsmaterialsau.1c00039. eCollection 2022 Mar 9.

Authors

Mikhail Kuzmin^{1

2}, Juha-Pekka Lehtiö¹, Zahra Jahanshah Rad¹, Svetlana V Sorokina², Marko P J Punkkinen¹, Hannu-Pekka Hedman³, Risto Punkkinen³, Pekka Laukkanen¹, Kalevi Kokko¹

Affiliations

¹ Department of Physics and Astronomy, University of Turku, FI-20014 Turku, Finland.
² Ioffe Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation.
³ Department of Information Technology, University of Turku, FI-20014 Turku, Finland.

Abstract

Properties of Ge oxides are significantly different from those of widely used Si oxides. For example, the instability of GeO _x at device junctions causes electronic defect levels that degrade the performance of Ge-containing devices (e.g., transistors and infrared detectors). Therefore, the passivating Si layers have been commonly used at Ge interfaces to reduce the effects of Ge oxide instability and mimic the successful strategy of Si oxidation. To contribute to the atomic-scale knowledge and control of oxidation of such Si-alloyed Ge interfaces (O/Si/Ge), we present a synchrotron radiation core-level study of O/Si/Ge, which is combined with scanning probe microscopy measurements. The oxidation processes and electronic properties of O/Si/Ge(100) are examined as functions of Si amount and oxidation doses. In particular, the incorporation of Si into Ge is shown to cause the strengthening of Ge-O bonds and the increase of incorporated oxygen amount in oxide/Ge junctions, supporting that the method is useful to decrease the defect-level densities.