| AVS 61st International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS1-WeM |
| Session: | Plasma Based Ion Implantation and Ion-Surface Interactions |
| Presenter: | Bo Vanderberg, Axcelis Technologies, Inc. |
| Authors: | B.H. Vanderberg, Axcelis Technologies, Inc. L.M. Rubin, Axcelis Technologies, Inc. A.M. Ray, Axcelis Technologies, Inc. |
| Correspondent: | Click to Email |
Plasma doping been described as a fledgling technology to complement and replace ion beam based implantation, due to its advantage in productivity given by the much higher average ion current delivered to work pieces. While productivity is an important factor in industrial applications, each technology also has to deliver appropriate dose control, and thus relies on advanced dosimetry systems to provide accurate dosage, high dose uniformity across the work piece, precise ion placement, i.e. energy and angle control, low contamination of undesired energetic and environmental species, and reliability and exception handling capability.
For commercial semiconductor manufacturing applications in particular, simultaneous compliance to each of these requirements is critical. Modern ion beam based implantation systems can provide dosimetry to meet these requirements, and we will describe some of the new technologies developed specifically for ion implantation of the most advanced semiconductor devices: fast data acquisition of multiple Faraday systems with parallel current collection, and measurement of spatial ion beam properties such energy and two-dimensional spatial and angle distribution, as well as their time dependence to monitor drift and intermittent failures.
For plasma doping to meet these standards, obstacles in terms of lack of mass-resolution, simultaneous implantation, deposition and etching, and lack of in situ beam monitoring during the plasma doping process represent formidable challenges. While some if the inherent shortcomings of plasma doping are fundamental, some techniques have been developed to address these issues, including novel Faraday systems as well as model based dosimetry with either theoretical or empirical modeling of plasma physical and chemical processes, some of which we will review.
The most difficult challenge for plasma doping is matching of dopant depth profiles of existing ion beam based implantation, where implanted dopant profiles as presented in the literature are different from their equivalent ion beam produced profiles. Without this capability, plasma doping of semiconductors is confined to a niche application space, covering less sensitive doping processes in semiconductor manufacture.