Multi-layer bispectral detector with photodiodes and method for manufacturing such a detector

摘要

The bispectral detector comprises a stack of upper and lower semiconductor layers of a first conductivity type for the absorption of first and second ranges of electromagnetic radiation, semiconductor areas of a second conductivity type that is opposite to first type, and electrically conducting elements connected to semiconductor areas for the collection of electric charges. The upper and lower semiconductor layers are separated by an intermediate layer that forms a barrier of potential between the upper (18) and lower layers (14). The bispectral detector comprises a stack of upper and lower semiconductor layers of a first conductivity type for the absorption of first and second ranges of electromagnetic radiation, semiconductor areas of a second conductivity type that is opposite to first type, and electrically conducting elements connected to semiconductor areas for the collection of electric charges. The upper and lower semiconductor layers are separated by an intermediate layer that forms a barrier of potential between the upper (18) and lower layers (14). Each semiconductor area in the lower layer is implanted partially in a bottom of recesses traversing the upper layer and an intermediate layer (16). The recess traversing the upper layer is separated from the upper layer by a second semiconductor barrier layer of a second conductivity type. A concentration of dopants of the second conductivity is greater than 10 1 7cm - 3. A thickness is chosen according to the concentration and is greater than a length of diffusion of the minority charge carrier in the barrier layer. Each semiconductor area in the upper layer forms a continuous volume with an adjacent semiconductor area in the lower layer. The intermediate layer is made of an insulating material or a semiconductor material of the first conductivity type of which a band gap is greater than three times of each of the upper and lower layers. An independent claim is included for a process for manufacturing a bispectral detector.