Radiation Damage Effects on Double-SOI Pixel Sensors for X-ray Astronomy

Abstract

The X-ray SOI pixel sensor onboard the FORCE satellite will be placed in the low earth orbit and will consequently suffer from the radiation effects mainly caused by geomagnetically trapped cosmic-ray protons. Based on previous studies on the effects of radiation on SOI pixel sensors, the positive charges trapped in the oxide layer significantly affect the performance of the sensor. To improve the radiation hardness of the SOI pixel sensors, we introduced a double-SOI (D-SOI) structure containing an additional middle Si layer in the oxide layer. The negative potential applied on the middle Si layer compensates for the radiation effects, due to the trapped positive charges. Although the radiation hardness of the D-SOI pixel sensors for applications in high-energy accelerators has been evaluated, radiation effects for astronomical application in the D-SOI sensors has not been evaluated thus far. To evaluate the radiation effects of the D-SOI sensor, we perform an irradiation experiment using a 6-MeV proton beam with a total dose of ~ 5 krad, corresponding to a few tens of years of in-orbit operation. This experiment indicates an improvement in the radiation hardness of the X- ray D-SOI devices. On using an irradiation of 5 krad on the D-SOI device, the energy resolution in the full-width half maximum for the 5.9-keV X-ray increases by 7 $\pm$ 2%, and the chip output gain decreases by 0.35 $\pm$ 0.09%. The physical mechanism of the gain degradation is also investigated; it is found that the gain degradation is caused by an increase in the parasitic capacitance due to the enlarged buried n-well.

arXiv comment7 pages, 7 figures, accepted for publication in NIM A

References in corpus (6)

• Improvement of Spectroscopic Performance using a Charge-sensitive Amplifier Circuit for an X-Ray Astronomical SOI Pixel Detector
• Development and Performance of Kyoto's X-ray Astronomical SOI pixel (SOIPIX) sensor
• Performance of the Silicon-On-Insulator Pixel Sensor for X-ray Astronomy, XRPIX6E, Equipped with Pinned Depleted Diode Structure
• In-orbit performance and calibration of the Hard X-ray Imager onboard Hitomi (ASTRO-H)
• Proton Radiation Damage Experiment for X-Ray SOI Pixel Detectors
• Sub-pixel Response of Double-SOI Pixel Sensors for X-ray Astronomy

Cited by in corpus (4)

• Sensor design optimization of innovative low-power, large area MAPS for HEP and applied science
• Proton radiation hardness of X-ray SOI pixel sensors with pinned depleted diode structure
• Radiation-Induced Degradation Mechanism of X-ray SOI Pixel Sensors with Pinned Depleted Diode Structure
• X-ray Radiation Damage Effects on Double-SOI Pixel Detectors for the Future Astronomical Satellite "FORCE"