(A) study on the analysis of radiation effect of infrared focal plane arrays readout integrated circuit for space applications

Abstract

In this paper, an analytic method of radiation effect of Readout Integrated Circuit (ROIC) for Infrared Focal Plane Arrays (IR FPAs) image sensor for space applications is presented. The electronic devices in satellites can be affected by the charged particles which have protons, electrons, α particles, heavy ions, and neutral particles in space. This radiation effect results to generate voltage difference, current leakage, and severely functional failure. The proposed method focuses on the analysis of the single event effect (SEE), one of the radiation effects. The analytic method of SEE consists of device simulation, modeling the single event effect in circuit-level, circuit simulation, and irradiation test processes. The transient analysis was performed to simulate charge collection in the device due to the SEE. The collected charges in electric field formed the drift current that can be thought the impulse current. By using this simulation result, the SEE model for circuit-level simulation was built and adapted to the circuit simulation. In order to analyze the radiation effect of ROIC, design of the appropriate readout circuit is required. The simple readout circuit, the direct injected (DI) type ROIC, was designed for convenience to analyze the radiation effect. The sensitive areas of DI type ROIC were the drain regions of MOSFETs. From the circuit simulation with the SEE model, the effect due to single event effect can be measured through the output voltage change. The output voltage change varies with the type of MOSFET at which the SEE model was attached. The designed readout circuit was fabricated with a 0.18-μm CMOS process. With a 45MeV cyclotron accelerator in Korea Institute of Radiological & Medical Sciences (KIRAMS), proton irradiation test was carried out for the designed ROIC. The used proton energies are 25, 30, and 37MeV. The effect due to irradiation test can be measured by the output voltage change. The median voltage of the output voltag...