Model-Based Ionized-PVD-Source Scaling and Performance: Hardware-Feasibility Study

Abstract

The ionized physical vapor deposition (IPVD) has been utilized in semiconductor processing for metallization and is still promising to extend coverage performance and combined with atomic layer deposition up to submicrometer technology. To aid further development of the hardware and process and address the extendability of IPVD technology to future nanoscale fabrication, the plasma fluid 2-D model was developed and used to study the impact of the geometry and the characteristics of the inductively coupled-plasma source incorporated in the IPVD system. The model comprises the 2-D axisymmetric equipment simulation code considering a Cu+Ar collisional mechanism, including charge exchange and Penning ionization, and a gas heating with rarefaction effect. An empirically based variable ion-mobility approach has been implemented to achieve convergency of the model solutions. The mechanism of the sputtered-metal thermalization was estimated by an analytical approach and incorporated into fluid model. The initial simulation results were validated and calibrated through experimental measurements of the plasma characteristics in the baseline IPVD system. The model outputs were related to the various geometrical configurations and used to investigate the hardware feasibility for qualitative (processlike) upscaling of the baseline IPVD system. In the process of the investigations, the novel solutions were obtained (segmented antenna and "bridged-slot" deposition baffle) and experimentally verified and tested. Hardware-feasibility study confirmed and predicted the technical potential of the scaling-up high-density plasma source integrated into IPVD system. A ground for more complex codes and virtual experiments utilizing 3-D models has been validated and established.