Metal-aluminum oxide–hafnium aluminum oxide‒silicon oxide–silicon (hereafter MAHAOS) devices can be candidates for ionizing radiation sensor applications. In this work, MAHAOS devices (SONOS-like structures with high k stack gate dielectric) were studied regarding the first known characterization of the ionization radiation sensing response. The change of threshold voltage V_T for a MAHAOS device after gamma ray exposure had a strong correlation to the total ionization dose (TID) of gamma radiation up to at least 5 Mrad TID. In this paper, the gamma radiation response performances of the pre-programmed and virgin (non-pre-programmed) MAHAOS devices are presented. The experimental data show that the change of V_T for the pre-programmed MAHAOS device with gamma irradiation is very significant. The data of pre-programmed MAHAOS devices written by 5 Mrad TID of gamma radiation was also stable for a long time with data storage. The sensing of gamma radiation by pre-programmed MAHAOS devices with high k stack gate dielectric reported in this study has demonstrated their potential application for non-volatile ionizing radiation sensing technology in the future.

This research demonstrates that an indium tin oxide–silicon oxide–hafnium aluminum oxide‒silicon oxide–silicon device with enhanced UV transparency ITO gate (hereafter E-IOHAOS) can greatly increase the sensing response performance of a SONOS type ultraviolet radiation total dose (hereafter UV TD) sensor. Post annealing process is used to optimize UV optical transmission and electrical resistivity characterization in ITO film. Via nano-columns (NCols) crystalline transformation of ITO film, UV transparency of ITO film can be enhanced. UV radiation causes the threshold voltage V_T of the E-IOHAOS device to increase, and the increase of the V_T of E-IOHAOS device is also related to the UV TD. The experimental results show that under UV TD irradiation of 100 mW·s/cm², ultraviolet light can change the threshold voltage V_T of E-IOHAOS to 12.5 V. Moreover, the V_T fading rate of ten-years retention on E-IOHAOS is below 10%. The V_T change of E-IOHAOS is almost 1.25 times that of poly silicon–aluminum oxide–hafnium aluminum oxide–silicon oxide–silicon with poly silicon gate device (hereafter SAHAOS). The sensing response performance of an E-IOHAOS UV TD sensor is greatly improved by annealed ITO gate.

This study compares the performance of two types of capacitive devices, indium tin oxide-aluminum oxide-zirconia aluminum oxide-silicon oxide-silicon (IAZAOS) and indium tin oxide-aluminum oxide-hafnium aluminum oxide-silicon oxide-silicon (IAHAOS), as silicon-oxide-nitride-oxide-silicon (SONOS) non-volatile memory (NVM) total dose of ultraviolet radiation (UV TD) sensors. Results show that IAZAOS with zirconia aluminum oxide as the charge-trapping layer outperforms IAHAOS with hafnium aluminum oxide for a UV TD sensor. After exposure to UV TD irradiation of 100 mW·s/cm², the threshold voltage (V_T) change of IAZAOS is almost 1.25 times that of IAHAOS. The study also found that annealing can significantly improve the response performance of IAZAOS UV TD sensors. Furthermore, IAZAOS devices with partially smaller nanocrystals in the charge-trapping layer greatly enhance the response of SONOS-type UV TD sensors. The study also compared the constant voltage stress-induced leakage current (CVSILC) and found that the CVSILC for annealed IAZAOS devices is 1000 times smaller than that of IAHAOS devices. Moreover, the IAZAOS-I2Z2 exhibits a superior performance regarding irradiation/refresh cycle endurance as compared to the IAHAOS-I2H1 device. These findings suggest that IAZAOS capacitive devices have superior performance and potential for use in SONOS-type UV TD sensors.

The titanium nitride–aluminum oxide–hafnium oxide–silicon oxide–silicon device using aluminum oxide as charge-blocking layer (hereafter TAHOS) could be a candidate for nonvolatile total ionization dose (TID) radiation sensor. In this paper, gamma radiation induces a significant decrease in the threshold voltage V_T of TAHOS and the radiation-induced V_T decrease on TAHOS is nearly 1.3 times of that on a standard titanium nitride–silicon oxide–hafnium oxide–silicon oxide–silicon device (hereafter TOHOS) device after 5 Mrad TID gamma irradiation. The change in V_T of TAHOS after gamma irradiation also has a strong correlation to TID up to 5 Mrad gamma irradiation. Moreover, the V_T 10yrs retention characteristic of TAHOS device can be markedly improved and is nearly 13% better than that of a standard TOHOS device after 5 Mrad gamma irradiation. Therefore, the TAHOS device in this study has demonstrated the possibility using TAHOS for high TID response and good TID data retention for non-volatile TID radiation sensing.