Hot‐wire CVD of copper films on self‐assembled‐monolayers of MPTMS

Abstract

AbstractSelf‐assembled monolayers (SAM's) of (3‐Mercaptopropyl)trimethoxysilane (MPTMS) were applied on Si (100) wafers covered either with low‐temperature silicon oxide (LTO) or with SiLK®. Cu films were subsequently chemically vapor deposited (CVD) on the MPTMS SAMs with a novel reactor equipped with a tungsten hot‐wire enabling the separate heating of the gas phase (hot‐wire CVD, HWCVD). CupraSelect®, which is the commercial name of hexafluoroacetylacetonate Cu(I) trimethylvinylsilane, was used as precursor for the deposition of Cu films and delivered in the reactor with the aid of a direct‐liquid injection system using ultra‐pure N2 as carrier gas. High quality Cu films were obtained on both LTO and SiLK®. The resistivities of HWCVD Cu films were found to be higher than those of thermally grown films. This is due possibly to the presence of impurities into the Cu films from the incomplete dissociation of the precursor and W impurities caused by the presence of the filament, which does not, however, degrade catastrophically the conductivity of Cu HWCVD films. The separate heating of the gas phase enhanced the deposition rate, which at filament temperature of 170 °C increases by a factor of approximately one and a half. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)