High performance SOI CMOS pixel sensor with surrounding N+ trench electrode

Abstract

In this paper, an advanced SOI CMOS pixel (ASCP) detector structure with deep N+ trench electrode is researched and simulated. For this pixel structure, the N+ trench cathode surrounds the P+ trench anode, and they are both connected from the topside. The cathode is in the function of charge share shielding, it isolates the neighbor pixels, and avoids the crosstalk happening of electron hole pairs. Furthermore, the parallel trench electrodes between anode and cathode have reduced the fully depleted voltage, and the bias voltage can be controlled from the core I/O interface. In addition, the ASCP has the better radiation resistance capacity as compared with the Conventional SOI CMOS pixel detector and the Three-Dimension (3D) CMOS detector, due to the low fully depleted voltage and short carrier drift distance. Numerical simulation results show that the ASCP detector has the better charge collecting capacity in low driving voltage, and it is more suitable to detect the back-illumination X-ray 55Fe.