Abstract: A method of forming an integrated circuit for the detection of infrared radiation comprising a semi-isolating substrate provided with a buried PIN photodiode, with a junction field effect transistor J-FET, whose gate is connected to the PIN photodiode, and with a resistor R connected to the transistor, this method including the growth of a first structure of epitaxial layers of semiconductor materials, in which the J-FET transistor is formed, the growth of a second structure of epitaxial layers of semiconductor materials, in which the PIN diode is formed, and the step of etching a pit, in which the second structure of layers is formed, characterized in that the step of etching the pit is effected after the growth of the first structure of epitaxial layers and is carried out through this structure down to the substrate, in that the growth of the second structure of epitaxial layers is localized in such a manner that this second structure is limited to the pit and in that its upper surface is copolanar with tha