A new technique for the precise measurement of gate oxide damage caused by process induced charging

Careful characterization of thin gate oxides aged with a tunneling current stress has shown a characteristic of the aging process that can be used to precisely calculate the damage produced in the oxide. This characteristic can be quantified by a simple measurement that correlates very well with the amount of tunneling current stress forced through an oxide. Process Induced Charging effects can damage an oxide by forcing high tunneling currents through the oxide. The amount of charge damage to an oxide can be difficult to measure. Generally, antenna transistors are used to monitor this problem with a shift in the transistor characteristics used to quantify the amount of damage. This can be difficult due to the non-linear relationship between the oxide damage and the transistor characteristics such as V_t or transconductance. This paper will describe the results of precise I-V characterization of a thin oxide following a tunneling current stress. The results show a near linear relationship between the magnitude of a transient leakage current from the “floating channel” region under the gate and the amount of tunneling current stress