(The) effect of $H_2$ plasma treatment on the film growth rate in catalytic-enhanced Cu CVD

Abstract

The effect of the surface pretreatment with $H_2$ plasma on the film growth rate in Cu CECVD (Catalytic-Enhanced Chemical Vapor Deposition), in which iodine was used with a Cu precursor of (hfac)Cu(vtms), is presented. Iodine has been recently known as a catalytic-surfactant in Cu MOCVD, which provides excellent surface smoothness, low film resistivity, and enhanced film growth rate. Before adsorbing iodine atoms on the surface of sputtered Cu seed-layers with a thickness of 200 Å using $C_2H_5I$ as an iodine source, the surface was pretreated with $H_2$ plasma. Even at the deposition temperature of 140℃, it drastically enhanced the film growth rate from 200 to 2000 Å/min. The enhancement of the film growth rate depends on the surface pretreatment time of $H_2$ plasma. From secondary ion mass spectroscopy (SIMS) analysis, it was confirmed that the surface pretreatment with $H_2$ plasma prior to $C_2H_5I$ adsorption increased the amount of iodine adatoms on the Cu seed-layer, thus enhancing the film growth rate about ten times as expected from the normal catalytic activity of iodine.