학술논문

Investigation of a Sequential Three-Dimensional Process for Back-Illuminated CMOS Image Sensors With Miniaturized Pixels
Document Type
Periodical
Source
IEEE Transactions on Electron Devices IEEE Trans. Electron Devices Electron Devices, IEEE Transactions on. 56(11):2403-2413 Nov, 2009
Subject
Components, Circuits, Devices and Systems
Engineered Materials, Dielectrics and Plasmas
Pixel
Logic gates
Transistors
Annealing
Bonding
Photodiodes
Silicon
CMOS image sensors (CISs)
fully depleted silicon-on-insulator (FDSOI) transistors
pixel miniaturization
sequential integration
3-D integration
Language
ISSN
0018-9383
1557-9646
Abstract
A new 3-D CMOS image sensor architecture is presented as a potential candidate for submicrometer pixels. To overcome the scaling challenge related to miniaturized pixel design rules, far beyond traditional 3-D stacking alignment capabilities, a sequential construction is applied. This paper gives a technical overview of this 3-D scheme and validates a part of its building blocks. As a consequence of a sequential process, the thermal budget is limited to ensure bottom device immunity. Subsequently, high-quality SOI film transfer above the first layer by direct bonding and etch back is demonstrated. Finally, the low-temperature processing of $\hbox{HfO}_{2}/\hbox{TiN}$ fully depleted silicon-on-insulator readout transistors is detailed and evaluated from a low frequency noise point of view.