Ph.D Thesis

Ph.D StudentBrouk Igor
SubjectSilicon-On-Insulator (SOI) CMOS Image Sensor with Front and
Back-side Illumination
DepartmentDepartment of Electrical and Computer Engineering
Supervisor PROFESSOR EMERITUS Yael Nemirovsky


CMOS image sensors are currently drawing much attention because they have the potential to compete with CCD cameras.

The purpose of this research was to investigate image sensors based on new CMOS / SOI-technology in comparison to regular CMOS image sensors (with novel designs). The research concentrated on the physical, the design, and the noise issues associated with active pixel sensors (APS) in CMOS/SOI technology and in comparison to the CMOS image sensors.

Two different architectures have been under study: the front-side illuminated and the back-side illuminated architectures. The back-side illumination is the more innovative one but the implementation required the development of the back-side thinning process. The front-side illuminated architecture allowed us to pursue the research goals regardless of the back-side technology. In addition, the front-side illuminated architecture is essential as a reference to the back-side approach.

The research focus was on the VLSI implementation of CMOS image sensor in various architectures, technologies as well as on the analog issues of the circuits. Since a novel part of the research is the back-side illumination architecture, a part of the research was involved in the development of a suitable technology for this architecture, which requires back-side thinning.

The research goals were achieved and the results are summarized in three main parts:

·        Study of VLSI CMOS image sensor design architectures:

- with front-side illumination;

- with back-side illumination.

·        Study of the different CMOS image sensor technologies (CMOS 0.5 mm, 0.35 mm; CMOS-SOI 0.35 mm):

- electro-optical characterization;

- 1/f Noise characterization;

- characterization of cross-talk between CMOS photodiodes.

·        Development of thinning technology for back-side illumination camera.

The main results are summarized in several publications and conference presentations.