Performance Improvement of SAONOS Device as UV-total-dose Nonvolatile Sensor with Al_2O_3/SiO_2 Bilayer Blocking Oxide

摘要

A silicon-alumina oxide-silicon oxide-silicon nitride-silicon oxide-silicon device with a bilayer Al_2O_3/SiO_2 blocking oxide (SAONOS device) is a candidate ultraviolet (UV) nonvolatile total dose (TD) radiation sensor. In this work, UV radiation induces a significant increase in the threshold voltage V_T for an SAONOS device under positive gate voltage (PGV). The change in V_T for the SAONOS device after UV radiation has a correlation with UV-TD up to 100 mW·s/cm~2 . The experimental results indicate that the radiation-induced increase in V_T for the SAONOS device under PGV is nearly 3 Ⅴ after 100 mW·s/cm~2 TD-UV radiation. The performance of the SAONOS device as a UV nonvolatile TD sensor was thus improved. Meanwhile, the experimental results show that the V_T retention performance of the SAONOS device after UV irradiation is also improved after 10 years of retention. The SAONOS device in this study has demonstrated its feasibility for UV nonvolatile TD radiation sensing application in the future.