Short-channel radiation effect in 60 MeV proton irradiated 0.13 μm CMOS transistors

The impact of a 60 MeV proton irradiation on the static characteristics of 0.13 mum CMOS transistors is investigated, as a function of the device length and width. It is shown that the degradation of the threshold voltage and of the transconductance exhibits a marked length dependence, with more pronounced changes for shorter devices. From the independence on the device width and the 2 nm gate dielectric (nitrided or reoxidized nitrided oxide), it is concluded that the basic damage mechanism is not related to the isolation or gate dielectric. The origin of the observed changes will be discussed in view of the two-dimensional doping profile, produced by lowly doped drain and pocket or halo implantations used to control the short-channel effects.