Method of making a transistor with high electron mobility.

摘要

Method of making an integrated circuit on a substrate (10) comprising steps for forming a high electron mobility transistor (HEMT), these steps including: - making a stack (11) of layers made on the substrate and among which there is at least one first layer (31) or channel in a material of small forbidden band width, and weakly doped, a second layer (22) or spacer in a material of larger forbidden band width, and weakly doped, and a third layer (23) or donor in a material of large forbidden band width, and strongly doped, these layers being surmounted by a fourth layer (24) or Schottky layer, - making a region of insulation with respect to the other elements of the integrated circuit, right around the transistor. This method also comprises the steps of: - forming, at the surface of the stack of layers, a mask (M) covering and delimiting the active region of the transistor; - etching the stack of layers down to the substrate (10) together with under-etching beneath the mask (M) in order to insulate the active region of the transistor through a MESA; - making a dielectric layer (K) by anisotropic deposition; - directional etching of the dielectric layer (K) whilst preserving the portions of this layer (K) which are protected by the mask (M) by virtue of the under-etching and which are arranged on the flanks of the MESA around the active region of the transistor; - removing the mask (M). Application: digital or analogue integrated circuits including HEMTs.