Mobile charge immune process

摘要

A semi conductor manufacturing process including uniform negative polarity wafer charging to remove or immobilize alkali ions such that the device becomes immune to their presence. The wafer is charged with a corona discharge at a 1MV/cm-2MV/cm bias field and low temperature (200 DEG C.-300 DEG C.) heating to bring mobile ions to the wafer's surface. Surface mobile ions are removed with a deionized (DI) water rinse or a standard sequential wafer wet cleaning step, immobilized with a normal gate (polysilicon) or metal contact formation step or both, thereby effectively removing mobile ions from the semiconductor structure.