Effect of Pre-Annealing in Preventing Gate Oxide Breakdown Voltage Degradation Induced by Polysilicon Gate Delineation Using Ion Milling

Abstract

Polysilicon gate MUS capacitors were fabricated using Kaufmann-type ion milling apparatus in gate electrode delineation. The breakdown voltage of the MOS capacitors was degraded when the polysilicon sheet resistance at the start of ion milling was higher than 20 kΩ/□. The degradation was prevented when the polysilicon sheet resistance was lowered by annealing to less than 2 kΩ/□ before ion milling.