Jean-Marc Girard

Enablement of cost effective CVD/ALD processing through precursor design

CVD and more recently ALD have become methods of choice for the deposition of new materials, to deal with the 3D nature of new devices, and to meet the requirement for atomic level thickness control. Several examples illustrate how precursor design can contribute to keeping the cost of new materials deposition in control, whether through easier facilitization thanks to better physical properties, or through process throughput enhancement.

Stabilization of Moisture-Premixed Copper Chemical Vapor Deposition Precursor and Applicability

Hexafluoroacetylacetonato copper(I) trimethylvinylsilane [Cu(hfac)tmvs] is currently the most documented precursor for copper chemical vapor deposition (CVD) for semiconductor applications. It is well known that some amount of moisture in the process chamber enhances the deposition rate. In the present study, we found that a water-premixed precursor could be made stable provided that the water was free from any trace of dissolved oxygen. Further improvement in stabilization was obtained in both cases by adding free tmvs. The practicality of this water-premixed precursor was also demonstrated for Cu deposition. No difference was observed for the deposited films in terms of their resistivity, crystallography, purity, or uniformity between the water-premix condition and separate addition of moisture. Furthermore, the optimum moisture concentration for copper deposition was lower than the solubility limit of water in the precursor, which makes this solution of practical interest. We conclude that the water-premixed Cu(hfac)tmvs is a suitable and sophisticated solution for application in the copper CVD process that reduces the hardware burden on the tool and limits the number of process variables.