UV Total Dose Nonvolatile Sensor Using Fluorine-Treated SOHOS capacitor

The fluorine-treated silicon–silicon oxide–hafnium oxide–silicon oxide–silicon capacitor device (hereafter F-SOHOS) could be candidate for UV radiation total dose (hereafter TD) nonvolatile sensor. UV radiation induces a significant increase in the threshold voltage V_T of the F-SOHOS. The experimental results indicate that the UV radiation-induced increase of V_T for the F-SOHOS capacitor device under gate positive bias stress (hereafter PVS) is nearly 4 volts after 100mW.sec/cm² TD UV radiation. The change in V_T for F-SOHOS capacitor after UV irradiation also has a strong correlation to UV TD up to 100mW.sec/cm² irradiation. The charge-retention loss of the nonvolatile F-SOHOS capacitor after 10 years retention is below 15%. The UV TD information can be permanently stored and accumulated in the non-volatile F-SOHOS capacitor devices. In order to erase the UV TD data, data in the F-SOHOS capacitor devices can be erased to original null state by positive charges injection under gate negative bias stress (hereafter NVS). The F-SOHOS capacitor device in this study has demonstrated the feasibility of non-volatile UV TD radiation sensing.