Transient Leakages of Gate Oxide Due to Charge Traps and Phosphorus Contaminants Induced During Gate Oxidation Processing

摘要

Two types of transient leakages in gate oxide due to charge traps and phosphorus contaminants induced during gate oxidation processing have been extensively examined. The reliability of gate oxide grown from a corroded silicon surface was degraded by the existence of charge traps locally on the pitted spots, resulting in irregularly transient leakages and early breakdowns. The regular transiency of leakages specifically within p-type gate oxide has been elucidated for the first time in connection with the excessive phosphorus contaminants as a constant source of defects at gate oxidation. By avoiding silicon surface corrosion or significant build-up of phosphorus contaminants, the gate oxide defects causing transient leakages have been eliminated and process robustness has been improved.