COPPER DRY-ETCHING TECHNIQUE FOR ULSI INTERCONNECTIONS

As a consequence of the well-known difficulties in reactive dry Cu pat terning only a small number of processes has been published world-wide . Using a simple Cl-2 based chemistry including an intense ion bombard ment as an alternative approach, the formation of thick sidewall films during etching (as proposed by other groups) is not necessary. As wil l be shown, a copper dry etching technique for interconnections down t o 0.2 mu m has been developed. The line resistance of PVD- and CVD-Cu has been measured indicating a good correlation with the calculated va lues. Finally, first electromigration resistance measurements of PVD-C u lines have been performed.