Experimental study of transient dose rate effect on radiation-hardened digital signal processor

Digital signal processors (DSPs) are increasingly being utilized in nuclear plants and instruments, and the transient dose rate effects (TDREs) they encounter due to radiation have become a significant concern. In this paper, the TDREs of DSP were investigated through experiments conducted at the Northwest Institute of Nuclear Technology in China. The DSP, designed to be radiation-hardened (Rad-Hard) and manufactured using a 0.13 μm Silicon-On-Insulator(SOI) process, was tested under four dose-rates ranging from 1.5 × 10¹¹ Rad(Si)/s to 2.0 × 10¹¹ Rad(Si)/s. The experimental results indicate that the disturbances in voltage and current induced by transient dose rate radiation are small, owing to radiation-hardened-by-design and the SOI process. The recovery time of the voltage in Rad-Hard DSP is shorter than that of conventional bulk silicon devices. This is attributed to the SOI MOS device having only horizontal parasitic junctions, a result of the presence of the buried oxide layer. The experimental results also demonstrate that the transient dose rate (TDR) threshold of the Rad-Hard DSP circuit can reach up to 1.6 × 10¹¹ Rad(Si)/s without functional failures and up to 2.0 × 10¹¹ Rad(Si)/s without latchup. In this work, the Rad-Hard DSP circuit's ability to withstand transient dose rate irradiation is shown to be one order of magnitude greater than that of bulk silicon counterparts.