NUCLEATION AND GROWTH OF CRYSTALLITES IN AMORPHOUS ANTIMONY LAYERS ON AS-DEPOSITED ULTRATHIN SUBLAYERS OF METAL - COPPER, SILVER, GOLD, TIN AND LEAD

Optical microscopy is used for the in situ observation of the nucleation and growth of crystallites in the amorphous antimony layer prepared on an as-deposited ultrathin sublayer of copper, silver, gold, tin or lead. A whole specimen is deposited on a cover glass in a vacuum of 1 × 10-4 Pa. With the use of sublayers of copper, gold and silver it is possible to measure the growth rate v of antimony crystallites as a function of thickness dSb of the antimony layer. An analysis of the relation of v to dSb on the basis of the model previously presented gives such parameters as the thicknesses ds0 and dv0 of surface regions near the substrate and the vacuum respectively and the growth rates us and uv at surfaces adjacent to the substrate and the vacuum respectively: ds0 = 2.0 nm, dv0 = 5.5nm, us = 11 μm s-1 and uv = 0.21 μm s-1 when dCu is 4.3 × 10-2 nm while ds0 = 0.7 nm, dv0 = 4.4 nm, us = 7.7 μm s-1 and uv = 0.13 μm s-1 when dAu is 4.0 × 10-2 nm. The effective activation energy for the growth of crystallites is determined from an Arrhenius plot of v from 30 to 60°C to be, for example, 1.2 eV at dSb = 3.0 nm and 0.7 eV at dSb = 5.2 nm when dCu is 4.3 × 10-2 nm while it is 1.0 eV at dSb = 2.2 nm and 0.9 eV at dSb = 3.7 nm when dAu is 4.0 × 10-2nm. Sublayers of tin and lead play an extremely progressive role on nucleation of antimony crystallites, resulting in such a high nucleation density that v could not be measured. This originates mainly from the larger area of interface between coupled layers of Sb/Sn or Sb/Pb according to electron microscopy. © 1990.