A High Full Well Capacity CMOS Image Sensor for Space Applications.

Woo-Tae Kim,Byung-Geun Lee,Hyunkeun Lee,Cheonwi Park,Ilseop Lee

doi:10.3390/s19071505

Abstract

This paper presents a high full well capacity (FWC) CMOS image sensor (CIS) for space applications. The proposed pixel design effectively increases the FWC without inducing overflow of photo-generated charge in a limited pixel area. An MOS capacitor is integrated in a pixel and accumulated charges in a photodiode are transferred to the in-pixel capacitor multiple times depending on the maximum incident light intensity. In addition, the modulation transfer function (MTF) and radiation damage effect on the pixel, which are especially important for space applications, are studied and analyzed through fabrication of the CIS. The CIS was fabricated using a 0.11 μm 1-poly 4-metal CIS process to demonstrate the proposed techniques and pixel design. A measured FWC of 103,448 electrons and MTF improvement of 300% are achieved with 6.5 μm pixel pitch.

Highlights

IntroductionImaging devices are essential components in the space environment for a range of applications including earth observation, star trackers on satellites, lander and rover cameras [1]
Imaging devices are essential components in the space environment for a range of applications including earth observation, star trackers on satellites, lander and rover cameras [1].In space applications, charge coupled devices (CCDs) have been used for imaging devices because they can achieve low noise and high image quality
Charge transfer efficiency (CTE) of CCDs is degraded by proton irradiation, which causes position shifts of objects in images and leads star trackers to cause uncorrectable errors [2]

Summary

Introduction

Imaging devices are essential components in the space environment for a range of applications including earth observation, star trackers on satellites, lander and rover cameras [1]. Charge coupled devices (CCDs) have been used for imaging devices because they can achieve low noise and high image quality. Charge transfer efficiency (CTE) of CCDs is degraded by proton irradiation, which causes position shifts of objects in images and leads star trackers to cause uncorrectable errors [2]. CCDs have a high power consumption because many external components and high supply voltages are necessary for their operation. These facts make CCDs less effective in the space environment

Methods

Results

Conclusion