The present paper summarizes the main features of the hollow cathode d
ischarges generated by a radio frequency (r.f.) instead of a d.c. held
. The pressure of gas inside the hollow cathode is almost independent
on the reactor pressure, which allows to generate discharge at high co
llision frequency and transport it into the low pressure reactor. The
discharge forced out from the hollow cathode forms a decaying plasma c
hannel with extraordinary properties. Gas metastables excited inside t
he cathode can act in selected gas mixtures as a source of additional
heat, thereby enhancing thermionic electron emission and ionization of
the gas. An are regime can be started from the glow discharge simply
by increasing the r.f. power. Hollow cathode are in the cathode metal
vapor can be sustained even without working gas. Examples of utilizati
on of hollow cathodes in the film deposition and dry etching technolog
y are presented. Small size cylindrical r.f. cathodes allow special ap
plications inside narrow (<10 mm in diameter) tubes. Linear are discha
rge (LAD) magnetrons.