Total Ionization Radiation Sensor Performance Improvement by Using Si-rich MONOS Device

Wen-Ching Hsieh,Tzu-I Tsai,Fuh-Cheng Jon,Shich-Chuan Wu,Hao-Tien Daniel Lee,Dawei Heh

doi:10.1051/matecconf/20167105007

Abstract

The Si-rich metal -oxide-nitride-oxide-silicon (hereafter Si-MONOS) can be candidates for non-volatile total ionization dose (TID) radiation sensors. In the case of Si-MONOS gamma radiation sensors, the gamma radiation induces a significant decrease of threshold voltage V T . The change of V T for Si-MONOS after gamma irradiation has a strong correlation to the TID of gamma ray exposure as well. The Si-MONOS capacitor device in this study has demonstrated the better feasibility for non-volatile TID radiation sensing in the future.

Highlights

In cases of Si-MONOS and MONOS capacitor devices, gamma ray radiation and fixed gate voltage was applied on these Si-MONOS and MONOS capacitor devices simultaneously for gamma ray data writing
These free carriers are swept by electric field, and some of them are captured by the charge trap centers, especially at the oxide-nitride (O-N) interface and silicon- oxide (S-O) interface
When a negative gate voltage VG is applied on these Si-MONOS and MONOS capacitor devices, the holes generated by radiation in the insulation layers are swept toward metal gate side by electric field, and some of the holes are captured by the charge trap centers at the O-N interface; electrons generated by radiation in the insulation layers are swept toward silicon base side by electric field, and some of electrons are captured by the charge trap centers at the O-N interface

Summary

Proposed Mechanism

In cases of Si-MONOS and MONOS capacitor devices, gamma ray radiation and fixed gate voltage was applied on these Si-MONOS and MONOS capacitor devices simultaneously for gamma ray data writing When these Si-MONOS and MONOS capacitor structures are irradiated by gamma rays, the electron-hole pairs are generated throughout the gate insulation layers. It is suggested that the amount of positive trapped charges in the SiONO gate dielectric layer is much greater than that in the ONO gate dielectric layer; so the decrease of VT for SiMONOS is more significant than that for MONOS This Si-MONOS capacitor device is potentially more suitable for the application of gamma ray dosimeter

Experimental

Threshold voltage shift after ionization radiation exposure

Gate leakage current after 10Mrad gamma ray exposure

Conclusions