Laser photodissociation of chlorine and methyl chloride on low‐temperature silicon substrates Available to Purchase

Laser irradiation at 193 or 351 nm of a multilayer of Cl₂ or CH₃Cl on an Si wafer at 100 K leads to both photodissociation of these molecules and formation of photoetching products. The kinetic energy distributions of photofragments (Cl, CH₃) and etching products (SiCl, SiCl₂) were measured. The kinetic energy distribution of Cl or CH₃ is bimodal for the case of thin deposition of parent molecules on substrates, in which the two‐component analysis of Maxwell–Boltzmann represents experimental results, assuming average kinetic energies of ∼1 and 10 kcal/mol. The etching products have kinetic energies of 1 kcal/mol. For the thick‐deposition case, the kinetic energy distribution of Cl or CH₃ fragments is composed of a single component with an average kinetic energy of 10 kcal/mol.