The invention relates to an avalanche photodiode-type semiconductor structure (1) intended to receive electromagnetic radiation in a given wavelength. The structure comprises a first semiconductor zone (210) with a first type of conductivity with a first longitudinal face (201), said first zone (210) being made of mercury-cadmium telluride of the CdxHg1-xTe type with a cadmium proportion x that is varied. The structure (1) also comprises at least one second semiconductor zone (310) in contact with the first zone (210), and a third semiconductor zone (410) in contact with the second zone (310). The first zone (210) comprises a doping element, such as arsenic, of which the concentration is varied alternately in a direction substantially perpendicular to the first longitudinal face (201) between a so-called low concentration and a so-called high concentration. The invention also relates to a process for producing a structure (1) according to the invention.