METHOD FOR PLASMA ETCHING A LAYER BASED ON A III-N MATERIAL

An object of the invention concerns a method for etching at least a portion (10c) of a layer (10) based on a III-N material, comprising exposing a least one portion of an upper face (10a) of the III-N layer (10) to a plasma (20) treatment with bias voltage pulsing based on chlorine, wherein the plasma (20) treatment is configured to present a duty cycle comprised between 20 % and 80 %, a first nonzero polarization bias Vbias-substrate1 being applied to the substrate (1) during Ton, and a second polarization bias |Vbias-substrate2| lesser than the |Vbias-substrate1| or no polarization bias being applied, during Toff, so as to etch the portion (10c) of the III-N layer (10); the duration of the etching is significantly reduced to obtain a satisfying quality of the III-N layer (10) for the operation of a microelectronic device, such as a transistor or a diode.