Drift of two-dimensional vacancy islands on the Si(100) surface under electromigration conditions

Vorontsova Iu.A., Sitnikov S.V. Drift of two-dimensional vacancy islands on the Si(100) surface under electromigration conditions. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2021, vol. 21, no. 5, pp. 664–669 (in Russian). doi: 10.17586/2226-1494-2021-21-5-664-669

The paper presents an experimental study of morphological changes of the Si(100) surface under electromigration conditions that was carried out using the in situ method involving ultrahigh vacuum reflection electron microscopy. The study aims to determine the temperature dependence of the effective electric charge of an adsorbed atom on the Si(100) surface. A system of concentric two-dimensional vacancy islands was formed on the surface of Si(100) samples by low-energy argon ion sputtering and subsequent high-temperature annealing. Quasi-equilibrium conditions were created on the sample surface by compensating the sublimating flow from the surface from an external silicon source. The video images of the drift of vacancy islands were recorded under the conditions of electromigration with the compensation of sublimation. Based on the processing and analysis of video images, the authors described the dependence of the velocity of motion of vacancy islands on the Si(100) surface for various temperatures and the direction of the electric current along and across the dimer rows with the (2 × 1) superstructure inside the island. It is shown that the drift rate of vacancy islands does not depend on their size under quasi-equilibrium conditions. A simplified one-dimensional theoretical model has been constructed. It includes one atomic step moving by a detachment of atoms from the step and their drift under the force of electromigration in the absence of desorption and deposition of atoms on the surface. Based on the proposed model, the effective electric charge is estimated, and the temperature dependence of the effective charge in the temperature range of 1010 to 1120 °C is obtained. The absolute value of the effective charge decreases linearly with increasing temperature. The sign of the effective charge is negative, and its average value is Z = –0.5 ± 0.3 elementary charges. The obtained results can be used for creating structures with a countable number of atomic steps and act as secondary measures of height with reference to the silicon crystal lattice.

1. Yasunaga H., Natori A. Electromigration on semiconductor surfaces. Surface Science Reports, 1992, vol. 15, no. 6-7, pp. 205–280. https://doi.org/10.1016/0167-5729(92)90007-x

2. Tamm I.E. On the Possible Bound States of Electrons on a Crystal Surface. Journal of Experimental and Theoretical Physics, 1933, vol. 3, pp. 34–43. (in Russian)

3. Rogilo D.I., Fedina L.I., Kosolobov S.S., Latyshev A.V. On the role of mobile nanoclusters in 2D island nucleation on Si(111)-(7 × 7) surface. Surface Science, 2018, vol. 667, pp. 1–7. https://doi.org/10.1016/j.susc.2017.09.009

4. Brocks G., Kelly P.J., Car R. Binding and diffusion of a Si adatom on the Si(100) surface. Physical Review Letters, 1991, vol. 66, no. 13, pp. 1729–1732. https://doi.org/10.1103/PhysRevLett.66.1729

5. Latyshev A.V., Krasilnikov A.B., Aseev A.L. Application of ultrahigh vacuum reflection electron microscopy for the study of clean silicon surfaces in sublimation, epitaxy, and phase transitions. Microscopy Research and Technique, 1992, vol. 20, no. 4, pp. 341–351. https://doi.org/10.1002/jemt.1070200405

6. Rogilo D.I., Fedina L.I., Kosolobov S.S., Ranguelov B.S., Latyshev A.V. Critical terrace width for two-dimensional nucleation during Si growth on Si(111)-(7х7) surface. Physical Review Letters, 2013, vol. 111, no. 3, pp. 036105. https://doi.org/10.1103/PhysRevLett.111.036105

7. Curiotto S., Müller P., El-Barraj A., Cheynis F., Pierre-Louis O., Leroy F. 2D nanostructure motion on anisotropic surfaces controlled by electromigration. Applied Surface Science, 2019, vol. 469, pp. 463–470. https://doi.org/10.1016/j.apsusc.2018.11.049

8. Curiotto S., Cheynis F., Müller P., Leroy F. 2D manipulation of nanoobjects by perpendicular electric fields: Implications for nanofabrication. ACS Applied Nano Materials, 2020, vol. 3, no. 2, pp. 1118–1122. https://doi.org/10.1021/acsanm.9b02517

9. Myers-Beaghton A.K., Vvedensky D.D. Generalized Burton-Cabrera-Frank theory for growth and equilibration on stepped surfaces. Physical Review A, 1991, vol. 44, no. 4, pp. 2457–2468. https://doi.org/10.1103/PhysRevA.44.2457

10. McLean J.G., Krishnamachari B., Peale D.R., Chason E., Sethna J.P., Cooper B.H. Decay of isolated surface features driven by the Gibbs-Thomson effect in an analytic model and a simulation. Physical Review B, 1997, vol. 55, no. 3, pp. 1811–1823. https://doi.org/10.1103/PhysRevB.55.1811

11. Kandel D., Kaxiras E. Microscopic theory of electromigration on semiconductor surfaces. Physical Review Letters, 1996, vol. 76, no. 7, pp. 1114–1117. https://doi.org/10.1103/PhysRevLett.76.1114

12. Stoyanov S. Electromigration induced step bunching on si surfaces-how does it depend on the temperature and heating current direction? Japanese Journal of Applied Physics, 1991, vol. 30, no. 1, pp. 1–6. https://doi.org/10.1143/JJAP.30.1

13. Latyshev A.V. Atomic Processes on a Crystal Surface. Tutorial. Novosibirsk. Novosibirsk State University, 2006, 96 p. (in Russian)

14. Nielsen J.-F., Pelz J.P., Hibino H., Hu C.-W., Tsong I.S.T. Enhanced terrace stability for preparation of step-free Si(001)-( 2×1) surfaces. Physical Review Letters, 2001, vol. 87, no. 13, pp. 136103. https://doi.org/10.1103/PhysRevLett.87.136103

15. Minoda H. Study of an effective charge of si adatoms on a Si(111) 1 × 1 surface. Journal of the Physical Society of Japan, 2002, vol. 71, no. 12, pp. 2944–2947. https://doi.org/10.1143/JPSJ.71.2944

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License