Real-time investigation of potassium growth by surface differential reflectance spectroscopy

The growth of potassium discontinuous films onto a low-temperature oxidized silicon substrate has been followed in real-time by surface differential r eflectance spectroscopy. The energy positions of the plasma resonances in t he potassium particles and their changes as a function of the amount of pot assium are related to the shape of the particles and to their interaction, Three stages in the formation of the film are determined: (i) nucleation of small spherical particles, (ii) growth and flattening of the particles, (i ii) coalescence.