Tranchée d'isolement profonde de type capacité MOS verticale pour les capteurs d'images CMOS

MOS Capacitor Deep Trench Isolation (CDTI) for CMOS Image Sensors

• Auteur / Autrice : Nayera Ahmed
• Direction : Guo Neng Lu, François Roy
• Type : Thèse de doctorat
• Discipline(s) : Microélectronique
• Date : Soutenance le 08/04/2015
• Etablissement(s) : Lyon 1
• Ecole(s) doctorale(s) : École doctorale Électronique, électrotechnique, automatique (Lyon)
• Partenaire(s) de recherche : Laboratoire : Institut des Nanotechnologies de Lyon (Ecully, Rhône)
• Jury : Président / Présidente : Francis Balestra
• Jury : Examinateurs / Examinatrices : Guo Neng Lu, François Roy, Rémi Barbier
• Jury : Rapporteurs / Rapporteuses : Albert J. P. Theuwissen, Patrick Garda

Mots clés

Mots clés contrôlés

Capteurs d'images à pixels actifs

Capteurs d'images CMOS

Microélectronique

Mots clés libres

Microélectronique

Capteurs d'images

Microelectronic

Image sensors

Résumé

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The development of high-resolution image sensors with smaller pixel sizes is facing critical issues, such as optical and electrical crosstalk, dark current and dynamic range. As part of this thesis, we addressed this issue by proposing the integration of MOS capacitor deep trench isolation (CDTI). Our studies focus on the validation of the proposal with the aim of improving performances compared to the state of the art. First, we modeled interface states Si/SiO2 and the charge in the oxide. By TCAD simulations, using our model, we were able to evaluate the main characteristics of a pixel. We have validated this approach by comparison between simulations and measurements on a 1.4μm DTI pixel. Then, we developed manufacturing processes for integrating CDTI and defined the associated key parameters. With TCAD simulations of process type, we could achieve the desired performances while keeping a short development cycle and cost. Finally, we have designed, manufactured and tested a 1.4μm CDTI pixel ; we got a very low dark current: ~ 1 aA/pixel at 60°C, which is 6 times less than the DTI pixel, and doubled saturation charge up to 12000e-. Other performances are comparable between the two types of pixels. We have demonstrated the validity of the proposed CDTI solution CDTI