Observation of hot-hole injection in NMOS transistors using a modified floating-gate technique

Abstract

A modified floating-gate technique for measuring small gate currents in MOSFET's with very high resolution (0.01 fA) is described. Using this technique, gate oxide currents due to hot-carrier injection are measured in n-channel MOSFET's. The conventional negative channel hot-electron gate oxide current is observed near <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">V_{g} = V_{d}</tex> and a small positive gate current occurs at low V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf> . We argue that the dependencies of this small positive current on V <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">g</inf> and gate length, together with results from a separate floating-source experiment, are consistent only with hot-hole injection.