SOME EFFECTS OF HYDROGEN ON Cu(TMVS)(HFAC) SOURCED CVD OF COPPER FILMS

摘要

We describe a study of the effects of hydrogen as a co-reactant and post-treatment of films grown by Cu(TMVS)(hfac) sourced Cu CVD on TaN substrates using an LPCVD system. We focus on the effects of hydrogen post-treatment on films grown with various amounts of water vapor as a co-reactant. As water vapor flow duration increases beyond 2 min, the resistivity continuously increases. Based on XRD data, we attribute the increased resistivity to the presence of Cu_2O. After deposition in the presence of water vapor, the films were treated with H2. Films exhibited lower resistivities after H_2 post-treatment. The improvement in resistivity was greater at higher substrate temperature. Residual gas analysis during the post-deposition treatment indicated H_2O in the reactor exhaust line. This water content is apparently due to reduction of Cu_2O to Cu. Our study also shows that the use of hydrogen as a carrier gas during deposition gives films with lower resistivities than using He. We conclude that the resistivity of the Cu films is improved with the use of hydrogen as carrier gas and post-treatment in Cu CVD process protocols.