کنفرانس بین المللی میکروالکترونیک ایران

صفحه اصلی / هفتمین کنفرانس بین المللی میکروالکترونیک ایران

Optimization and Characterization of CrossTalk in CMOS image sensors

نویسندگان :

Asma Mojarrad Alman abad¹ Hamzeh Alaibakhsh²

1- دانشگاه علم و صنعت ایران 2- دانشگاه علم و صنعت ایران

کلمات کلیدی :

CMOS image sensor،crosstalk،floating diffusion،deep trench isolation،diffusion current،built-in electric field

چکیده :

With the widespread adoption of CMOS image sensors (CIS) in various industries, pixel density in each array has increased to enhance sensor sensitivity. As pixel density rises, the distance between adjacent pixels decreases, leading to interpixel leakage current, commonly known as crosstalk (CTK), which has become a critical issue, particularly under low-light conditions. Addressing this challenge requires a comprehensive study of how different structural parameters of the pixel affect CTK. In this work, a 2D characterization of the impact of two key pixel design parameters-surrounding doping of the floating diffusion (〖FD〗_SD) and photodiode depth (Δ)- on CTK is investigated for a 170 nm pixel. Results reveal a dual behavior of the photodiode with respect to the changes in wavelength. At short wavelengths, reducing 〖FD〗_SD and increasing Δ lead to higher CTK, whereas at longer wavelengths, CTK shows an entirely different trend. Our analysis reveals that 〖FD〗_SDexhibits an 80% linear correlation with CTK. Furthermore, implementing deeper photodiodes can reduce CTK by up to 80% at long wavelengths. These findings demonstrate that careful engineering of 〖FD〗_SD and photodiode depth can significantly improve photodiode performance by minimizing CTK.