4T CMOS Active Pixel Sensors under Ionizing Radiation

This thesis investigates the ionizing radiation effects on 4T pixels and the elementary in-pixel test devices with regard to the electrical performance and the optical performance. In addition to an analysis of the macroscopic pixel parameter degradation, the radiation-induced degradation mechanisms are also presented from the microscopic perspective in terms of activation energy, the Meyer-Neldel relationship, and the trap capture cross section. In order to strengthen the radiation tolerance of 4T CMOS image sensors, some radiation-hardening-by-design techniques are proposed based on the understanding of the preceding study on the radiation effects. The effectiveness of the radiation-hardened techniques is also verified by being compared to a reference pixel array without radiation protection techniques