Measurement of the Energetics of Metal Film Growth on a Semiconductor: Ag/Si(100)-(2 x 1)

The first direct calorimetric measurements of the energetics of metal film growth on a semiconductor surface are presented. The heat of adsorption of Ag on Si(100)-(2 x 1) at 300K decreases from ∼347 to 246 kJ/mol with coverage in the first monolayer (ML) due to overlap of substrate strain from nearby Ag islands. It then rises quickly toward the bulk sublimation enthalpy (285 kJ/mol) as 3D particles grow. A wetting layer grows to 1.0ML, but is metastable above ∼0.55 ML and dewets when kinetics permit. This may be common when adsorbate islands induce a large strain in the substrate surface nearby