Ions such as sodium and potassium that can move within the gate oxide. They drift with field and temperature and shift the threshold voltage. Because they can come from sources such as human sweat, they are tightly controlled.
Field: Oxidation and diffusion
This reduces threshold shifts from mobile ions and improves oxide reliability such as breakdown strength, and also suppresses oxidation-induced stacking faults.
What is the main purpose of adding a small amount of chlori…Sodium becomes mobile ions in oxide films and shifts transistor threshold voltages, while organics cause defects in film deposition and bonding.
What is the main reason wafers must not be touched with bar…Threshold voltage Gettering Thermal oxidation Bird's beak Deal-Grove model Drive-in Dry oxidation Forming gas anneal Interface states LOCOS