Chemical and discharge effects in plasma etching with freons and other electronegative gases

Low pressure plasmas of halogens, halo carbons and their mixtures are in general use for etching micron size features on Si, GaAs and InP. Several processing parameters may be varied to attain the optimum conditions for a particular process in terms of etching rates and profile control. The effects of the manipulation of process variables such as pressure, applied frequency, and gas feed composition, are discussed. Specific examples are presented to show these effects in relation to the etching of Si and III–V compounds.