Neutralization of wafer charging in nitrogen gas

In an attempt to prevent wafers from getting charged in the N₂ gas sealed semiconductor manufacturing process, the authors have developed a neutralization method employing ultraviolet (UV) irradiation. This method depends on the fact that the N₂ molecule is ionized when it absorbs ultraviolet light. This method is superior to the neutralization method employing corona discharge in terms of neutralization capability in the inert gas ambient. The neutralization rate is very high; the residual potential caused by the unbalanced ion distribution is always 0 V after the neutralization. Neutralization is rapid. The neutralization capability is enhanced by decreasing the ambient pressure. The neutralization capability is further enhanced by replacing the N₂ gas ambient with the Ar gas ambient