A deep-level transient spectroscopy study of transition metals in n-type germanium

• Published in: Materials science in semiconductor processing 2006-08, Vol.9 (4), p.559-563
• Main Authors: Forment, S., Vanhellemont, J., Clauws, P., Van Steenbergen, J., Sioncke, S., Meuris, M., Simoen, E., Theuwis, A.
• Format: Article
• Language: English
• Subjects: Applied sciences; Deep-level; Electronics; Exact sciences and technology; Germanium; Microelectronic fabrication (materials and surfaces technology); Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2006.08.048

The deep-level parameters of a number of technological relevant transition metals—Hf, Ti, Cr, Fe, Co and Ni—in n-type germanium have been studied by deep-level transient spectroscopy (DLTS). The metals have been introduced by ion implantation followed by annealing at 500 °C for 5 min. In most cases the annealing treatment is sufficient to remove the implantation point defects from the substrate, leaving only metal-related electron traps in the spectra. From the fact that for each metal, one (or more) peaks at a different position and with a different activation energy is observed, it is concluded that levels specific for the individual metals have been detected. This is further validated by the observation that the corresponding trap concentration increases with the implantation dose. In some cases, e.g. Hf, we believe that it is the first observation of the impurity-related deep electron traps in germanium.