Abstract: A SPAD-type photodiode has a semiconductor substrate with a light-receiving surface. A lattice formed of interlaced strips made of a first material covers the light receiving surface. The lattice includes lattice openings with lateral walls covered by a spacer made of a second material. Then first and second materials have different optical indices, and further each optical index is less than or equal to the substrate optical index. A pitch of the lattice is of the order of a magnitude of an operating wavelength of the photodiode. The first and second materials are transparent at that operating wavelength. The lattice is made of a conductive material electrically coupled to an electrical connection node (for example, a bias voltage node).
Type:
Grant
Filed:
August 21, 2014
Date of Patent:
March 29, 2016
Assignees:
STMicroelectronics (Crolles 2) SAS; STMicroelectronics SA, Commissariat A L'Energie Atomique et aux Energies Alternatives
Inventors:
Michel Marty, Laurent Frey, Sebastien Jouan, Salim Boutami