Effects of helicon-wave-plasma etching on the charging damage of aluminum interconnects

Abstract

The etching parameters of aluminum in the helicon wave plasma are characterized to elucidate the mechanism of charging damage. By increasing the ion energy and decreasing the plasma density via increase of the bias power and decrease of the source power, respectively, we can significantly reduce charging damage, On the basis of this concept, we develop a two-step etching technique to suppress the charging damage without selectivity loss. Such a high-density plasma etching technique will be very suitable for the formation of high-density, and narrow-line interconnects.