SURFACE-MEDIATED REACTION PATHWAYS OF 2,4-PENTANEDIONE ON CLEAN AND OXYGEN-COVERED CU(210)

2,4-Pentanedione, also called acetylacetone (Hacac) is a precursor tha t has been considered for copper etching, or as a carrier for copper i n copper deposition. Generally, 2,4-pentanedione is less effective tha n other similar molecules. In this article, temperature-programmed des orption was used to examine the decomposition of acetylacetone adsorbe d on clean and oxygen precovered Cu (210) to see if we could understan d how the chemistry of 2,4-pentanedione is different than that of anot her species, hexafluoroacetylacetone. On the clean surface, several re action pathways were found including decomposition and desorption of 2 ,4-pentanedione. Most notable was that 2,4-pentanedione lost a methyl group below 300 K. By comparison hexafluoropentanedione is stable on a n oxidized copper surface to 600 K. These results show that 2,4-pentan edione decomposes at temperatures below that for formation of volatile copper species. In contrast, hexafluoropentanedione is stable to temp eratures above where the volatile copper species desorbs. We suggest t hat the difference in stability of the two molecules leads to the diff erence in etching characteristics that has been observed previously. ( C) 1998 American Vacuum Society. [S0734-2101(98)00905-1].