Formation and decomposition of <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Ge</mi></mrow><mrow><mi mathvariant="italic">x</mi></mrow></msub></mrow></math><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Si</mi></mrow><mrow><mi mathvariant="italic">l</mi><mi mathvariant="normal">−</mi><mi mathvariant="italic">x</mi></mrow></msub></mrow></math>(100)(2×1):H and <math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Ge</mi></mrow><mrow><mi mathvariant="italic">x</mi></mrow></msub></mrow></math><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msub><mrow><mi mathvariant="normal">Si</mi></mrow><mrow><mi mathvariant="italic">l</mi><mi mathvariant="normal">−</mi><mi mathvariant="italic">x</mi></mrow></msub></mrow></math>(100)(1×):2H

J. A. Schaefer; J. Q. Broughton; J. C. Bean; H. H. Farrell

doi:10.1103/PhysRevB.33.2999

Formation and decomposition of ${Ge}_{x}$ ${Si}_{l - x}$ (100)(2×1):H and ${Ge}_{x}$ ${Si}_{l - x}$ (100)(1×):2H

J. A. Schaefer, J. Q. Broughton, J. C. Bean, and H. H. Farrell

Phys. Rev. B 33, 2999 – Published 1 March 1986

Abstract

Using high-resolution electron-energy-loss spectroscopy, we have investigated the formation and thermal decomposition of both the monohydride and the dihydride phases formed by exposing the (100) surface of Ge-Si alloys to atomic hydrogen. Ge monohydride and dihydride thermally decompose in the same temperature range as does Si dihydride (500 to 600 K) while Si monohydride persists to above 700 K. Using hydrogen as a marker, we were able to monitor the concentration of surface substrate atoms and found substantial Ge enrichment of the top surface layer relative to the bulk concentration. Variations in the surface composition as a function of temperature, bulk concentration, and H exposure were observed in some detail.