High quantum efficiency photodetector

US9640704B2 · kind B2 · utility

Assignees

• COMMISSARIAT A L'ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES · FR
• STMicroelectronics SA

Inventors

• Laurent Frey · Fontaine, FR
• Michel Marty · Buc, FR

Key dates

• Filing date: May 24, 2016
• Grant date: May 2, 2017
• Expiry date: May 24, 2036

Classification

• Technology area (CPC H): Electricity
• CPC primary: H10F77/413

Abstract

A photodetector including a photoelectric conversion structure made of a semiconductor material and, on a light-receiving surface of the conversion structure, a stack of first and second diffractive elements, the second element being above the first element, wherein: the first element includes at least one pad made of a material having an optical index n1, laterally surrounded with a region made of a material having an optical index n2 different from n1; the second element includes at least one pad made of a material having an optical index n3, laterally surrounded with a region made of a material having an optical index n4 different from n3; the pads of the first and second elements are substantially vertically aligned; and optical index differences n1−n2 and n3−n4 have opposite signs.