Abstract: A field-effect transistor comprising a stack of semiconductor materials, the upper face of the stack being covered with a passivation layer comprises two sub-layers: a first sub-layer extending over a second zone of low intensity comprising a first material with electric breakdown field Ecl1, the charge of the first sub-layer being strictly less than the charge of the upper face of the stack, a second sub-layer extending over a first zone of high intensity and covering the first sub-layer, the second sub-layer comprising a second material with electrical breakdown field Ecl2 strictly greater than Ecl1.