Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Clément Lobre

Giacomo Badano

Florent Rochette

Jean-Paul Chamonal

Roch Espiau De Lamaestre

François Boulard

A method for manufacturing a photodetection device, which includes the following steps:

Process for manufacturing a low-noise photodetector device in a CdHgTe substrate

Photo-detection device () including a semiconductor substrate () made of CdHgTe, with an N-doped region (), a P-doped region (), and a concentrated casing () only located in the P-doped region and having an average cadmium concentration greater than the average cadmium concentration in the N-doped region. According to the invention, the concentrated casing () has a cadmium concentration gradient, defining therein at least one intermediate gap zone () and at least one high gap zone (), and the intermediate gap zone () is in direct physical contact with an electrical contact block (). A significant reduction in the dark current and an optimal charge carrier collection are thus combined.

Photodetection device having a lateral cadmium concentration gradient in the space charge zone

A photodetection device including a pixel matrix, each of the pixels including a photodiode, the absorption region of which extends entirely or almost entirely inside a volume surrounding a central region of the pixel; and a focusing element. An assembly of focusing elements is composed of refractive structures, each formed by a first truncated pyramid with a recess in the shape of a second inverted pyramid. The angles &#x3c6;at the base of the pyramids satisfy the following relation: wherein nis the optical index of a medium surrounding the refractive structures on the side opposite the photodiodes, and nis an optical index of the refractive structures.

Matrix of photodetectors with peripheral absorption provided with focussing structures

The invention pertains to a process for producing an array () of mesa-structured photodiodes (), including at least the following steps: a) producing a useful layer (); b) producing an etch mask formed of a plurality of etch pads (); c) wet-etching part of the useful layer () located between the etch pads (), forming a plurality of mesa-structured photodiodes (), producing a recess (); d) conformally depositing a passivation layer (); e) removing the etch pads () by chemical dissolution; f) producing conductive pads ().

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Grenoble, France

Clément Lobre