FABRICATION OF A NANOMETER-SCALE GAAS RIDGE STRUCTURE WITH A 92-MHZ ANODE-COUPLED REACTIVE ION ETCHER USING CL-2 N-2 MIXED PLASMAS/

A vertical etch profile of GaAs is achieved at a low bias voltage with a 92-MHx anode-coupled reactive ion etcher using chlorine-nitrogen pl asmas. The added nitrogen gas not only dilutes the concentration of re active chlorine radicals in the plasma also plays an important role in the vertical etching of GaAs. XPS analysis reveals no sidewall passiv ation by nitrogen. Reactive ion etching: with a Cl-2/N-2 mixed plasma was used to fabricate ultra-fine GaAs patterns with a nanometer-scale ridge structure having a cross-section 15-nm wide by 150-nm high.