Enhanced Sensitivity of CMOS Image Sensors by Stacked Diodes

We have investigated and compared the performance of photodiodes built with stacked p/n junctions operating in parallel versus conventional ones made with single p/n junctions. We propose a method to characterize and compare photodiodes sensitivity. For this purpose, a dedicated chip in the standard...

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Detalles Bibliográficos
Autores: Leñero Bardallo, Juan Antonio, Delgado Restituto, Manuel, Carmona Galán, Ricardo, Rodríguez Vázquez, Ángel Benito
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2016
País:España
Institución:Universidad de Sevilla (US)
Repositorio:idUS. Depósito de Investigación de la Universidad de Sevilla
OAI Identifier:oai:idus.us.es:11441/90615
Acceso en línea:https://hdl.handle.net/11441/90615
https://doi.org/10.1109/JSEN.2016.2611759
Access Level:acceso abierto
Palabra clave:Stacked photodiodes
Spectral sensitivity
Photodiode characterization
Event-based vision sensors
NIR
Descripción
Sumario:We have investigated and compared the performance of photodiodes built with stacked p/n junctions operating in parallel versus conventional ones made with single p/n junctions. We propose a method to characterize and compare photodiodes sensitivity. For this purpose, a dedicated chip in the standard AMS 180-nm HV technology has been fabricated. Four different sensor structures were implemented and compared. Experimental results are provided. Measurements show sensitivity enhancement ranging from 55% to 70% within the 500-1100 nm spectral region. The larger increment is happening in the near infrared band (up to 62%). Such results make stacked photodiodes suitable candidates for the implementation of photosensors in vision chips designed for standard CMOS technologies.