The Effect of Electroactive Defects in the Gate Oxide on the Threshold Voltage of a Submicron MOS Transistor

A new mechanism underlying the effect of the gate oxide geometry on the threshold voltage and other electrical properties of an MOS transistor (MOST) is proposed. This mechanism includes a relationship between the ionized center concentration in the gate oxide and its length. The dependence of the charge on these centers on the gate oxide configuration is associated with hydrogen redistribution between the gate and side oxide layers, as well as with the superposition of the ionized center distributions in the oxide layer along its horizontal and vertical boundaries in the peripheral drain and source contact windows. The revealed strong dependence of the charge density of the ionized centers in the oxide layer on the gate configuration (up to charge polarity reversal) specifies the strong dependence of the threshold voltage on the configuration of the gate and side oxide layers.