Anomalous leakage current in LPCVD PolySilicon MOSFET's

Abstract

The anomalous leakage current I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</inf> in LPCVD polysilicon MOSFET's is attributed to field emission via grain-boundary traps in the (front) surface depletion region at the drain, and an analytic model that describes the strong dependences of I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</inf> on the gate and drain voltages is developed. The model predictions are consistent with measured current-voltage characteristics. Physical insight afforded by the model implies device design modifications to control and reduce I <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</inf> , and indicates when the back-surface leakage component is significant.