Palladium seeding on the tantalum-insulated silicon oxide film by plasma immersion ion implantation for the growth of electroless Copper

The major aim of this study was to combine the techniques of using plasma i mmersion ion implantation (PIII) and electroless plating to implant Pd onto a Ta diffusion barrier layer as catalyst for the electroless Cu plating in order to accomplish the ULSI interconnection metallization. In our study, it has been demonstrated that the accelerating Pd+ ions by 2 kV pulsed nega tive bias voltages produce an amorphous Pd layer on P-Ta. The outermost Pd forms an oxide to the chemisorption of oxygen on Pd in air, while innermost Pd does not react with P-Ta, but instead remains in the form of metallic P d. The Pd doses in the range of 5.7 x 10(14) and 8.6 x 10(14) cm(-2) invoke s an excellent catalytic effect on the electroless Cu plating. This results in an extraordinary ability for filling the submicron holes for gaining hi gh quality electroless plated Cu interconnects, and thus qualifies for the traditional wet activation by SnCl2 and PdCl2 solutions. (C) 2000 Elsevier Science B.V. All rights reserved.