Stress measurement of Si(111)77 reconstruction during atomic hydrogen adsorption

Uozumi, Yuki; Asaoka, Hidehito  

We have succeeded in measurements of the surface stress in Si(111) as a function of 77 reconstruction by comparison with the H-terminated Si(111) 11 surface. In order to obtain information on both the surface stress and the surface reconstruction simultaneously, we havecombined the surface-curvature and the reflection-high-electron-energy-diffraction instrumentations in an identical ultrahigh vacuum system. The stress evolution shows a decrease of tensile stresscorresponding to the formation of H-termination at the beginning of the atomic hydrogen exposure of Si(111) 77 surface. After the above treatment, a complete transformation of the surface structure occurs from the reconstructed surface to the 11 one. As a result, we find the Si(111) 11 surface releases 1.7 N/m (=J/m), or (1.4 eV/(11 unit cell)), of the surface energy from the strong tensile Si(111) 77 reconstruction.