Radiation-Induced Defects in 8T-CMOS Global Shutter Image Sensor for Space Applications

Abstract

We propose to identify the displacement damage defects induced by proton and carbon irradiations in a com mercial off-the-shelf pinned photodiode (PPD) 8T-CMOS image sensors (CISs) dedicated to space application operating in global shutter mode. This paper aims to provide a better understanding of defects creation in a specific space image sensor. Therefore, it leads to comparable results to those we could find during the mission. The study focuses on bulk defects located in the PPD depleted region which represents the main dark current contribution in PPD CIS. Four sensors have been irradiated with carbon ions and protons at different energies and fl uencies. Using both the dark current spectroscopy and the random telegraph si gn al (RTS) analysis, we investigate defects behavior for different isochronal a,mealing temperatures. By combi1ùng these results, we make the connection between two complementary phenomena and bring out the prevalence of divacancies-based defects in terin of dark current contribution.

Comparison of X-Ray and Electron Radiation Effects on Dark Current Non-Uniformity and Fluctuations in CMOS Image Sensors

“…9 in dashed lines for the 3-MeV electron irradiation. This typical generation dark current signature has already been observed in PPD CIS after alpha particle irradiations [27] and after low energy and end-of-range (EOR) proton irradiations [28], [29] at the same dark current values and the same annealing treatments. It is not surprising to see similar results for low energy proton, alpha particle, and electron irradiations as they both involve the same displacement mechanisms known as elastic Coulombic interactions leading to a majority of point defects.…”

“…10 with the color scale. The dark current generation peaks referred to as 2, 3, and 4 with the highest DDD contribution share the same activation energy at 0.63 eV confirming the presence of the same defects highlighted in [27]- [29] at the same activation energy. With a temperature of formation close to 200 • C and a similar activation energy, oxygen-based point defects (i.e., V 2 O, V 2 O 2 ) could be one of the responsible structures for these dark current signatures [30], [31].…”

Effects of Hot Pixels on Pixel Performance on Backside Illuminated Complementary Metal Oxide Semiconductor (CMOS) Image Sensors

“…Hence, the cluster defect has a complex structure compared to the isolated defect and is the candidate resulting in the production of hot pixels. To harvest the energy level of the defects, dark current was tested at distinct temperatures, and the corresponding activation energy was calculated according to the Arrhenius law [25][26][27].…”

“…Considering the temperature dependence of the Si bandgap, we obtain the expression of activation energy as a function of the energy level into the silicon bandgap as: To harvest the energy level of the defects, dark current was tested at distinct temperatures, and the corresponding activation energy was calculated according to the Arrhenius law [25][26][27].…”

An Improved Global Shutter Pixel with Extended Output Range and Linearity of Compensation for CMOS Image Sensor

“…However, the large power consumption, the complex structure and the incompatibility between the process and the mainstream silicon processing are the disadvantages of the 7T pixel structure. 4) On the basis of the 4T APS pixel, two storage nodes are added to form an 8T double capacitance global pixel circuit structure [ 15 ] . Since the reset level and signal level are stored in the same cycle, the noise level of the output signal can be greatly reduced in the read‐out phase through correlated double sampling.…”