Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Nanochemistry at the atomic scale revealed in hydrogen-induced semiconductor surface metallization


Passivation of semiconductor surfaces against chemical attack can be achieved by terminating the surface-dangling bonds with a monovalent atom such as hydrogen. Such passivation invariably leads to the removal of all surface states in the bandgap, and thus to the termination of non-metallic surfaces. Here we report the first observation of semiconductor surface metallization induced by atomic hydrogen. This result, established by using photo-electron and photo-absorption spectroscopies and scanning tunnelling techniques, is achieved on a Si-terminated cubic silicon carbide (SiC) surface. It results from competition between hydrogen termination of surface-dangling bonds and hydrogen-generated steric hindrance below the surface. Understanding the ingredient for hydrogen-stabilized metallization directly impacts the ability to eliminate electronic defects at semiconductor interfaces critical for microelectronics, provides a means to develop electrical contacts on high-bandgap chemically passive materials, particularly for interfacing with biological systems, and gives control of surfaces for lubrication, for example of nanomechanical devices.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Atomic models of the clean and H-covered β-SiC(100) 3 × 2 surfaces.
Figure 2: Scanning tunnelling microscopy topographs (empty electronic states) and spectra provide an atomic-scale view of the clean and hydrogen-covered β-SiC(100) 3 × 2 surfaces.
Figure 3: Valence-band photoemission spectroscopy spectra (hν = 16.85 eV) providing the filled electronic density of states for the β-SiC(100) 3 × 2 clean and hydrogen-covered surfaces, in particular the develop ment of states at the Fermi level.
Figure 4: Multiple internal reflection infrared absorption spectroscopy (MIR–IRAS) provides information about H–Si bonding configurations, and low-energy electronic transitions.


  1. 1

    Oura, K., Lifshits, V.G., Saranin, A.A., Zotov, A.V. & Katayama, M. Hydrogen interaction with clean and modified silicon surfaces. Surf. Sci. Rep. 35, 1–69 (1999).

    CAS  Article  Google Scholar 

  2. 2

    Higashi, G.S. & Chabal, Y.J. in Handbook of Silicon Wafer Cleaning Technology: Science, Technology, and Applications (ed. Kern, W.) 433–496 (Noyes, Park Ridge, New Jersey, 1993).

    Google Scholar 

  3. 3

    Boland, J.J. Structure of the H-saturated Si(100). Phys. Rev. Lett. 65, 3325–3328 (1990).

    CAS  Article  Google Scholar 

  4. 4

    Derycke, V., Fonteneau, P., Pham, N.P. & Soukiassian, P. Molecular-hydrogen interaction with β-SiC(100)3×2 and c(4×2) surfaces and with Si atomic lines. Phys. Rev. B 63, 201305 (2001).

    Article  Google Scholar 

  5. 5

    Higashi, G.S., Chabal, Y.J., Trucks, G.W. & Raghavachari, K. Ideal hydrogen termination of the Si(111) surface. Appl. Phys. Lett. 56, 656–658 (1990).

    CAS  Article  Google Scholar 

  6. 6

    Schluter, M. & Cohen, M.L. Nature of conduction-band surface resonances for Si(111) surfaces with and without chemisorbed overlayers. Phys. Rev. B 17, 716–719 (1977).

    Article  Google Scholar 

  7. 7

    Becker, R.S., Higashi, G.S., Chabal, Y.J. & Becker, A.J. Atomic scale conversion of clean Si(111):H-1×1 to Si(111)-2×1 by electron-stimulated desorption. Phys. Rev. Lett. 65, 1917–1920 (1990).

    CAS  Article  Google Scholar 

  8. 8

    Pusel, A. & Wetterauer, U. & Hess, P. Photochemical hydrogen desorption from H-terminated Si(111) by VUV photons. Phys. Rev. Lett. 81, 645–648 (1998).

    CAS  Article  Google Scholar 

  9. 9

    Vondrak, T. & Zhu, X.Y., Direct photodesorption of atomic hydrogen from Si(100) at 157 nm: experiment and simulation. J. Phys. Chem. B 103, 4892–4899 (1999).

    CAS  Article  Google Scholar 

  10. 10

    Fowler, A.B. IBM Corporation, Armonk, New York. Process for the elimination of interface states in MIOS structures. US patent 3,849,204 (1974).

  11. 11

    Lyding, J.W., Hess, K. & Kizilyalli, I.C. Reduction of hot electron degradation in metal oxide semiconductor transistors by deuterium processing. Appl. Phys. Lett. 68, 2526–2528 (1996).

    CAS  Article  Google Scholar 

  12. 12

    Becker, R.S., Becker, A.J., Higashi, G.S. & Chabal, Y.J. Surface chemical reactions studied with scanning tunnelling microscopy. Scan. Microsc. 7 (suppl.), 269–280 (1993).

    CAS  Google Scholar 

  13. 13

    Foley, E.T., Kam, A.F., Lyding, J.W. & Avouris, P. Cryogenic UHV-STM study of hydrogen and deuterium desorption from Si(100). Phys. Rev. Lett. 80, 1336–1339 (1998).

    CAS  Article  Google Scholar 

  14. 14

    Shen, T.-C. et al. Atomic-scale desorption through electronic and vibrational excitation mechanisms. Science 268, 1590–1592 (1995).

    CAS  Article  Google Scholar 

  15. 15

    Watanabe, S., Ono, Y.A., Hashizume, T., Wada, Y., Yamauchi, J. & Tsukada, M. Electronic structure of an atomic wire on a hydrogen-terminated Si(111) surface: first-principles study. Phys. Rev. B 52, 10768–10771 (1995).

    CAS  Article  Google Scholar 

  16. 16

    Doumergue, P., Pizzagalli, L., Joachim, C., Altibelli, A. & Baratoff, A. Conductance of a finite missing hydrogen atomic line on Si(001)–(2×1)–H. Phys. Rev. B 59, 15910–15916 (1999).

    CAS  Article  Google Scholar 

  17. 17

    Bowler, D.R. & Fisher, A.J. Small polaron formation in dangling-bond wires on the Si(001) surface. Phys. Rev. B 63, 035310/1–4 (2001).

    CAS  Google Scholar 

  18. 18

    Maier, F., Riedel, M., Mantel, B., Ristein, J. & Ley, L. Origin of surface conductivity in diamond. Phys. Rev. Lett. 85, 3472–3475 (2000).

    CAS  Article  Google Scholar 

  19. 19

    Bermudez, V.M. Structure and properties of cubic silicon carbide (100) surfaces: a review. Phys. Status Solidi B 202, 447–473 (1997).

    CAS  Article  Google Scholar 

  20. 20

    Soukiassian, P. Cubic silicon carbide surface reconstructions and Si (C) nanostructures at the atomic scale. Mater. Sci. Eng. B 96, 115–131 (2002).

    Article  Google Scholar 

  21. 21

    D'angelo, M. et al. in Proc. Eur. Conf. Silicon Carbide Related Mat. 2002 — ECSCRM' 2002 (eds Bergman, P. & Janzén, E.) (Materials Science Forum, in the press).

  22. 22

    Semond, F., Soukiassian, P., Mayne, A.J., Dujardin, G., Douillard, L. & Jaussaud, C. Atomic structure of the β-SiC(100) 3×2 surface. Phys. Rev. Lett. 77, 2013–2016 (1997).

    Article  Google Scholar 

  23. 23

    Lu, W., Kruger, P. & Pollmann, J. Atomic and electronic structure of β-SiC(001) 3×2. Phys. Rev. B 60, 2495–2504 (1998).

    Article  Google Scholar 

  24. 24

    Soukiassian, P. et al. Direct observation of a β-SiC(100) c(4×2) surface reconstruction. Phys. Rev. Lett. 78, 907–910 (1997).

    CAS  Article  Google Scholar 

  25. 25

    Catellani, A., Galli, G., Gygi, F & Pellacini, F. Influence of stress and defects on the silicon-terminated SiC(001) surface structure. Phys. Rev. B 57, 12255–12261 (1998).

    CAS  Article  Google Scholar 

  26. 26

    Aristov, V.Yu., Douillard, L., Fauchoux, O. & Soukiassian, P. Temperature-induced semiconducting c(4×2) metallic 2×1 reversible phase transition on the β-SiC(100) surface. Phys. Rev. Lett. 79, 3700–3703 (1997).

    CAS  Article  Google Scholar 

  27. 27

    Yeom, H.W. et al. Electronic structure of the Si-rich 3C–SiC(001) 3×2 surface. Phys. Rev. B 58, 10540–10550 (1998).

    CAS  Article  Google Scholar 

  28. 28

    Reutt, J.E., Chabal, Y.J. & Christman, S.B. Coupling of H vibration to substrate electronic states in Mo(100)-p(1×1)H and W(100)-p(1×1)H: example of strong breakdown of adiabaticity. Phys. Rev. B 38, 3112–3132 (1988).

    CAS  Article  Google Scholar 

  29. 29

    Chabal, Y.J. & Raghavachari, K. Surface infrared study of Si(100)-(2×1)-H. Phys. Rev. Lett. 53, 282–285 (1984).

    CAS  Article  Google Scholar 

  30. 30

    Chabal, Y.J. Infrared spectroscopy of hydrogen on silicon surfaces. Physica B 170, 447–456 (1991).

    CAS  Article  Google Scholar 

  31. 31

    Chabal, Y.J. & Raghavachari, K. New ordered structure for the H-saturated Si(100) surface: the (3×1) phase. Phys. Rev. Lett. 54, 1055–1058 (1985).

    CAS  Article  Google Scholar 

  32. 32

    Chabal, Y.J., Higashi, G.S., Raghavachari, K. & Burrows, V.A. Infrared spectroscopy of Si(111) and Si(100) surfaces after HF treatment: H termination and surface morphology. J. Vac. Sci. Technol. A 7, 2104–2109 (1989).

    CAS  Article  Google Scholar 

  33. 33

    Sieber, N., Stark, T., Seyller, Th., Ley, L., Zorman, C.A. & Mehregany, M. Origin of the split Si–H stretch mode on hydrogen terminated 6H-SiC (0001): titration of crystal truncation. Appl. Phys. Lett. 80, 4726–4729 (2002).

    CAS  Article  Google Scholar 

  34. 34

    Raghavachari, K., Jakob, P. & Chabal, Y.J. Step relaxation and surface stress at H-terminated vicinal Si(111). Chem. Phys. Lett. 206, 156–160 (1993).

    CAS  Article  Google Scholar 

  35. 35

    Soukiassian, P., Semond, F., Mayne, A. & Dujardin, G. Highly stable Si atomic line formation on the β-SiC(100) surface. Phys. Rev. Lett. 79, 2498–2501 (1997).

    CAS  Article  Google Scholar 

  36. 36

    Soukiassian, P. & Dujardin, G. Des lignes d'atomes au diamant. La Recherche 321, 38–41 (1999).

    Google Scholar 

  37. 37

    Soukiassian, P. in Physics, Chemistry and Application of Nanostructures (eds Borisenko, V. E., Gaponenko, S. V. & Gurin, V. S.) 340–353 (World Scientific, 2001).

    Book  Google Scholar 

  38. 38

    Bechstedt, F. et al. Towards quantum structures in SiC. Mater. Sci. Forum 389–393, 737–742 (2002).

    Article  Google Scholar 

  39. 39

    Salmeron, M. Generation of defects in model lubricant monolayers and their contribution to energy dissipation in friction. Tribol. Lett. 10, 69–79 (2001).

    CAS  Article  Google Scholar 

Download references


The authors are grateful to W.L. Brown for his leadership of the IRAS work done at Agere Systems and many discussions, to V. Yu. Aristov, N.P. Pham, N. Rodriguez and S. Saada for their support of the STM/STS and photo-emission work done at CEA-Saclay and Elettra (Trieste), to G. Galli and S. Laetitia for discussions, to C. Ottaviani and M. Pedio for assistance in the synchrotron radiation experiments done at Elettra (Trieste), to T. Billon, L. di Cioccio and C. Pudda (CEA-LETI), and A. Lescuras (CNRS-CHREA) for providing single-domain β-SiC(100) samples.

Author information



Corresponding author

Correspondence to Patrick G. Soukiassian.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Movie showing the different steps of the interaction of hydrogen atoms with the β-SiC(100) 3x2 surface

1) Hydrogen atoms decorating the Si dangling bonds of the topmost surface (GIF 291 kb)

Subsequently, Si-Si dimers in the first plan becoming symmetric

2)The hydrogen atoms then breaks the Si-Si dimers in the 3rd atomic layer below the surface (located just above the 1st carbon plane) resulting in the formation of 2 dangling bonds

3) H atom decorating one of these dangling bond but, due to steric conditions and lack of space, unable to decorate the second one

4) This results in a charge transfer into the underlying plane leading to Metallisation.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Derycke, V., Soukiassian, P., Amy, F. et al. Nanochemistry at the atomic scale revealed in hydrogen-induced semiconductor surface metallization. Nature Mater 2, 253–258 (2003).

Download citation

Further reading


Quick links