Novel Static Magnetron Triode Reactive Ion Etching

Static magnetron triode reactive ion etching (SMTRIE) has been developed as a new method that achieves high-rate and high-uniformity etching with low metal oxide semiconductor (MOS) damage. An overview of the method is provided together with an application to Al-Cu etching. Four axisymmetric coils produce radial magnetic flux near and parallel to the etching cathode, and cylindrical magnetic flux parallel to the surrounding side cathode. This field creates a magnetron-type discharge near both cathodes, thus producing high plasma density that is both axisymmetrically and radially uniform. Al-Cu etching results demonstrate the excellent uniformity of SMTRIE. In addition, no gate damage was observed even at high power or under relatively poor uniformity. SMTRIE is one of the most promising etching methods for application to deep submicron geometries where precise and low-damage etching are indispensable.