Hourglass transistor: An alternative and improved MOS structure robust to total ionization dose radiation

This paper presents a novel MOSFET layout named the “hourglass transistor”, aimed to improve its electrical behavior under Total Ionizing Dose (TID) effects. The new radiation-tolerant device is based on augmenting parasitic channel resistance, alteration of the electric field by the longitudinal corner effect (LCE), and reducing channel resistance within the central gate region. The radiation-robust MOS structure design was implemented in a 130 nm CMOS bulk process and its performance was analyzed through simulations using 3D physical models. The proposed hourglass transistor was compared with rectangular, diamond, dog bone and H-gate devices, showing a reduction in the post-radiation I o f f current of 8.77, 4.6, 1.85 and 13.7 times, respectively; and a pre-radiation normalized saturation current of 2.29, 1.04, 1.58 and 1.52 times greater with an increase of 4.84, 1, 2.47 and 2.03 times the gate area, respectively.