Hot electron effects : theories and modeling of commercially available MOSFET processes

Near submicrometer MOSFETs suffer stress degradation caused by impact ionization from hot electrons. In order to predict the short term and long damage from hot electron stress, 1.2µ and 2.0µ MOSFETS from a commercial foundry are experimentally studied. Drain current degradation results are presented for the linear and saturation regions. A review of current literature theory on hot electron effects in MOSFETs is included. SPICE modeling parameters for hot electron induced substrate current in NMOS and PMOS devices are resolutely determined. Long term drain current degradation rates are determined for dc stress times of up to six decades. These rates are useful in predicting MOSFET parameter changes for a wide range of stress biasing. Drain current degradation rates are measured for NMOSFETs oriented both in the orientation of stress and with the drain and source reversed.