Germanium-based planar photodiode with a compressed lateral peripheral zone

A planar photodiode, including:

• a detection portion of a main semiconductor layer, made of at least one germanium-based crystalline semiconductor material M0, having first and second faces parallel to a main plane, and including:
• a p-type doped first region, flush with the first face;
• a n-type doped second region, flush with the second face;
• and an intermediate region, extending between the first and second doped regions, and surrounding the second doped region in the main plane while being flush with the second face;
• a peripheral lateral portion, intended to be electrically polarized, made of at least one first electrically-conductive material M1, extending, along a vertical axis orthogonal to the main plane, until coming into contact with the first doped region, and extending in contact with the detection portion while surrounding the intermediate region in the main plane;
• the first material M1 having a coefficient of thermal expansion CTE1 lower than that of the material M0, extending from the first face,
• the intermediate region including a first portion P1, surrounded by the first material M1 in the main plane, having mechanical tensile stresses;
• wherein the peripheral lateral portion includes several distinct electrically-conductive materials, stacked on top of one another along the vertical axis, including:
• at least one second material M2, extending between the first material M1 and the second face, having a coefficient of thermal expansion CTE2 higher than or equal to that of the material M0,
• the intermediate region including a second portion P2 flush with the second face F2, surrounded by the second material M2 in the main plane, formed by a peripheral lateral area Z2p having mechanical compressive stresses, which surrounds a central area Z2c in the main plane having mechanical tensile stresses and where the second doped region is located.