Observation of RF plasma-induced potential on a grid dielectric within a plasma laser

摘要

RF plasma-induced potentials on relatively thin gate dielectric layers capable of conducting by a Fowler-Nordheim mechanism may be accurately determined by employing as potential sensing structure an EEPROM cell having its control gate capacitively coupled to the substrate through a gate dielectric layer which reproduces the condition of an intervening discharge through a Fowler-Nordheim current. The connection is interrupted by a polyfuse before measuring the threshold voltage of the sensing EEPROM cell. The measured peak potential values induced by the plasma depend on the thickness of the gate dielectric layer, as they will be on production wafers. The normalization of the "antenna" area of the sensing structures will permit to precisely evaluate the electrical stress induced by the plasma on sensitive integrated structures. IMAGE