Impact of 24-GeV proton irradiation on 0.13-μm CMOS devices

We studied the response of a commercial 0.13-μm CMOS technology to high-energy (24-GeV) proton irradiation, which emulated the environment the front-end electronics of future high energy accelerators will have to operate in, for fluences up to 10¹⁶ p/cm². After irradiation, large negative shifts in the threshold voltage and large drops in the maximum transconductance were observed in PMOSFETs, whereas comparatively smaller effects were present in NMOSFETs. Furthermore, both kinds of devices exhibited an increase in the drain off-current and in the gate leakage current. All the observed effects were roughly proportional to the proton fluence. For PMOSFETs only, the amount of the degradation depended on the device channel length. The changes in the characteristics of the irradiated devices were attributed to the build-up of positive charge in the LDD spacer oxide and to the creation of defects in the gate oxide.