Speaker
Mr
Laurent Artola
(ONERA)
Description
**1. Introduction**
CMOS technology is widely used in Image sensors and Infrared detector onboard spacecrafts [1]. Actually, many optical applications, like Earth or space observation, the guidance system in a spacecraft (launcher or satellite) are particularly critical. Photonic imager technology has been developed for various wavelengths from ultraviolet, through visible, to infrared. For IR detectors, the MCT material (HgCdTe) is used for the detection circuit. The detection circuit is hybrided on a CMOS circuit which performs the transfer and the control of the IR detector. The CMOS technology used in the readout circuit (ROIC) improves the integration of electronics function. A readout circuit is composed by vertical decoders, multiplexers, sequencer, and various logics and sequential cells.
However, these digital CMOS functions of image sensors are known to be sensitive to single event effects (SEE), such as single event transient (SET) or Single Event Functional Interrupt (SEFI) [2]. SETs can be induced by various ionizing particles, i.e., especially heavy ions and protons for the space environment space.
The first goal of this paper is to present the impact or not of cryogenic temperatures on SET and SEFI induced by heavy ions on two different readout circuits of IR image sensors developed by Sofradir.
The second goal is to analyze the multiplicity of SETs and to determine the origin of such events by the mean of the prediction tool MUSCA SEP3 (MUti-SCAle Single Event Phenomena Prediction Platform) [4-5]. Such analyze is relevant with the aim to anticipate the SEE sensitivity trends and propose new radiation tests protocol for IR detectors.
**2. Radiation test of ROIC under heavy ions at cryogenic temperatures**
The two readout circuits have been developed by Sofradir and work at 5 V. During the whole SEE tests, the ROIC and its pixel tables was under the heavy-ion beams. The results only characterized the silicon system bare ROIC without MCT attached. The SEE test campaign was performed at UCL with the heavy-ion test facility in Louvain la Neuve, Belgium. Three samples of each readout integrated circuit (ROIC) type were characterized in order to evaluate the device variability. During all the testing measurements, the temperature of the chip was monitored and regulated, by means of dedicated equipment to a range of temperature from 50K to 300K. More details of the radiation setup will be presented in the final paper.
Large SET, short SETs, and SEFI were measured during the test campaign. Large and short SETs were defined as a function of the length of the event observed on the VIDEO signal. The multiplicity of SET allowed classifying two more categories: simple and complex SETs. More details will be given in the final paper.
**3. SEE analysis**
Various SET signatures were identified. These signatures highlighted the difference in term of SEE location: in the pixel array, and on the vertical decoder of the pixel table. A very low sensitivity of SEFI was measured. The multiplicity of the short and large SET events was investigated and analyzed by means of histograms. The two categories of multiplicity were identified depending on the event location: occurrence one up to four SETs is due to an event in the pixel array, while a SEE occurrence with a higher SET multiplicity is due to an event on an adjacent control circuit. This analysis was confirmed by simulations performed with the SEE simulation tool MUSCA SEP3. This point will be fully illustrated in the final paper.
Experimental data of short and large SETs obtained for a large range of temperature from 50 up to 300 K during the heavy-ion irradiations highlighted a limited impact of the temperature susceptibility of the two ROICs. The same trend was observed for SEFI. More details and discussed will be proposed in the final paper. Moreover, the results also highlighted a limited impact of the part–to-part variability in the same lot on the occurrence of SET susceptibility at cryogenic temperature for the two ROICs.
**4. Conclusion and perspectives**
This work presented the analyses of single event transients and functional interrupts measured on two designs of readout integrated circuit under a heavy ions beam cooled down at cryogenic temperatures. The analysis of the multiplicity of SETs in the pixel arrays was completed by means of the SEE prediction tool, MUSCA SEP3. Experimental data confirmed the very limited impact of the cryogenic temperature on SEE occurrence on the two ROICs. These results are consistent with previous simulation results on elementary gates (DFF) [6]. It appears that for this technology used by Sofradir for their ROIC of IR detectors, the future irradiation test campaigns should be realized at room temperature. This allows for reducing the complexity of such irradiation tests during the development of IR detector for a space mission.
**References**
[1] G. R. Hopkinson, IEEE Trans. Nucl. Sci., vol. 47, no, 6, pp. 2480-2484, Dec. 2000.
[2] C. Virmontois, et al, IEEE Trans. Nucl. Sci., vol. 61, no. 6, pp. 3331-3340, Dec. 2014.
[3] G. Hubert, et al, IEEE Trans. Nucl. Sci., vol. 56, no. 6, pp. 3032-3042, Dec. 2009.
[4] G. Hubert, et al, IEEE Trans. Nucl. Sci., vol. 60, no. 6, pp. 4421-4429, Dec. 2013.
[5] L. Artola et al, et al, IEEE Trans. Nucl. Sci., vol. 62, no. 6, pp. 2979-2987, Dec. 2015.
[6] L. Artola etal, IEEE Trans. Nucl. Sci., vol. 65, no. xx , pp. xxxx-xxxx, 2018.
Summary
This work presents the analyses of single event transients and functional interrupts measured on two designs of readout integrated circuit under a heavy ions beam cooled down at cryogenic temperatures. The analysis of the multiplicity of SETs in the pixel arrays is completed by means of the SEE prediction tool, MUSCA SEP3.
Primary author
Mr
Laurent Artola
(ONERA)
Co-authors
Dr
Ahmad Al Youssef
(ONERA / Sofradir)
Mr
Christian Poivey
(ESA ESTEC)
Mr
Guillaume Hubert
(ONERA)
Mr
Raphael Buiron
(Sofradir)
Dr
Samuel Ducret
(Sofradir)
