Frequency shift of the Si-H vibrational modes on erbium silicide measured by HREELS

被引:9
作者
Angot, T
Koulmann, JJ
Bolmont, D
Gewinner, G
机构
[1] Lab. Phys. Spectrosc. Electron. - U., Fac. des Sci. et Techniques, 68093 Mulhouse Cedex, 4, rue des Freres Lumiere
关键词
electron spectroscopy; hydrogen; lanthanides; low index single crystal surfaces; metal-semiconductor interfaces; silicides; silicon; surface chemical reaction;
D O I
10.1016/S0039-6028(96)01049-7
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Hydrogen adsorption on two-dimensional (2D) ErSi2/Si(111) as well as on a 300 Angstrom thick ErSi1.7(0001) film on Si(lll) has been studied by HREELS. Both surfaces exhibit the characteristic monohydride Si-H bending and stretching modes confirming the structural model of a silicide terminated by a buckled silicon plane similar to the ideal Si(111) termination. Nevertheless when compared to the Si(111)-delta(7x7)H or Si(001)-(2x1)H surfaces, these modes are found to be shifted towards lower energies: approximately 25 cm(-1) for the 2D silicide and 65 cm(-1) for the thick silicide. This provides an example of a marked change in the Si-H surface vibration frequencies induced by a modification in the third atomic layer below the surface i.e. in the third coordination shell of the adsorbate. The shift is interpreted as a weaker Si-H force constant on the silicide apparently related to a small reduction in bond order because of electron donation from the Er layer underneath.
引用
收藏
页码:190 / 195
页数:6
相关论文
共 32 条
[11]   ADSORPTION STATES AND ADSORPTION-KINETICS OF ATOMIC-HYDROGEN ON SILICON CRYSTAL-SURFACES [J].
FROITZHEIM, H ;
KOHLER, U ;
LAMMERING, H .
SURFACE SCIENCE, 1985, 149 (2-3) :537-557
[12]   ANHARMONIC POTENTIAL CONSTANTS AND THEIR DEPENDENCE UPON BOND LENGTH [J].
HERSCHBACH, D ;
LAURIE, VW .
JOURNAL OF CHEMICAL PHYSICS, 1961, 35 (02) :458-&
[13]  
IBACH H, 1991, ELECTRON ENERGY LOSS
[14]   EPITAXIAL-GROWTH OF RARE-EARTH SILICIDES ON (111) SI [J].
KNAPP, JA ;
PICRAUX, ST .
APPLIED PHYSICS LETTERS, 1986, 48 (07) :466-468
[15]  
LANNOO M, 1991, SPRINGER SERIES SURF
[16]   Interface structure of Si(111)-(root 3x root 3)R30 degrees-ErSi2-x [J].
Lohmeier, M ;
Huisman, WJ ;
Vlieg, E ;
Nishiyama, A ;
Nicklin, CL ;
Turner, TS .
SURFACE SCIENCE, 1996, 345 (03) :247-260
[17]  
LOHMEIER M, 1995, THESIS AMSTERDAM
[18]  
LOHMEIER M, UNPUB
[19]   THE INFLUENCE OF GROWTH TECHNIQUES ON THE STRUCTURE OF EPITAXIAL ERSI1.7 ON SI(111) [J].
LOLLMAN, DBB ;
TAN, TAN ;
VEUILLEN, JY ;
MURET, P ;
LEFKI, K ;
BRUNEL, M ;
DUPUY, JC .
APPLIED SURFACE SCIENCE, 1993, 65-6 :704-711
[20]   SURFACE RECONSTRUCTION OF ERSI1.7(0001) INVESTIGATED BY SCANNING-TUNNELING-MICROSCOPY [J].
ROGE, TP ;
PALMINO, F ;
SAVALL, C ;
LABRUNE, JC ;
WETZEL, P ;
PIRRI, C ;
GEWINNER, G .
PHYSICAL REVIEW B, 1995, 51 (16) :10998-11001