Ionising Radiation Effects on MOSFET Drain Current

We showed that a single heavy ion can wipe out the MOSFET driving current capability in small W devices. In this case the damaged oxide region may span over a large portion of the gate width, effectively hampering the channel formation. In large W devices, this effect becomes less important as W becomes larger than the damaged region. Noticeably, Moore’s law is acting in the sense of making MOSFETs more sensitive to localized damage by shrinking the device dimensions. What will happen with oxides thinner than 2nm and alternative gate dielectrics is open to investigation. All these considerations lead to the conclusion that a MOSFET with small W may fail due to a single ion hit producing SEDC2 well before the oxide breakdown condition is reached. RSB or SEGR may occur a long time after the device has lost most of its current driving capability and is, therefore, failed. In this case the device lifetime can no more be evaluated by considering the breakdown onset but, instead, its sensitivity to microdose effects such as those produced by high LET particles.