[en] We have generated beams with electron current densities of more than 10 m A/cm² at energies between 150 and 900 eV using a plasma source. This electron source can be operated at background pressures between 0.01 and 0.1 Torr in helium and with the addition of various gases, producing electron beams up to 3.8 cm in diameter. The broad-area beam can be used to induce gas-phase and surface reactions and has been successfully used to achieve anisotropic etching of SiO₂ and Si films in reactant gases CF₄ and SF₆. (Author). 14 refs, 10 figs