We have demonstrated a new technique for direct patterning and formation of cobalt silicide structures using focused ion beam implantation. This mask-free-fabrication technique takes advantage of the influence on the kinetics of ion-beam mixing and properties of thin barrier oxides during silicide line formation. Silicide structures with dimensions of the order of 170 nm were produced on (100) silicon substrates. The process involves the ion implantation of 200 keV As++ through a thin cobalt film on SiO2/Si structure. A selective reaction barrier at the Si/Co interface comprising of a thin (∼2 nm) oxide (SiO2), prevents unwanted reactions with silicon. Ion-beam mixing was instrumental in fracturing of the oxide layer; thereby, allowing the migration of metal atoms across the Si/Co boundary for the silicidation reaction to proceed during subsequent rapid thermal anneal treatments. Diffusion controlled reactions advanced rapidly in the implanted areas, requiring a two-step anneal sequence to inhibit reaction elsewhere. A threshold dose of 3 × 1015 cm-2 was required for process initiation. Four-terminal resistance test structures were formed for electrical measurements. Resistivity obtained ranged on the order of 12 to 23 μΩ-cm. Application of this method can facilitate a wide variety of silicide structures.
|Title of host publication
|Proceedings of the International Conference on Ion Implantation Technology
|Institute of Electrical and Electronics Engineers Inc.
|Number of pages
|Published - 2002
|2002 14th IEEE International Conference on Ion Implantation Technology, IIT 2002 - Taos, United States
Duration: Sep 22 2002 → Sep 27 2002
|2002 14th IEEE International Conference on Ion Implantation Technology, IIT 2002
|9/22/02 → 9/27/02
- Direct write
- Ion beam
ASJC Scopus subject areas
- Electrical and Electronic Engineering
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics