The study of impurity diffusion in semiconductor hosts is an important field that has both fundamental appeal and practical applications. Ion implantation is a good technique to introduce impurities deep into the semiconductor substrates at relatively low temperature and is not limited by the solubility of the dopants in the host. However ion implantation creates defects and damages to the substrate. Annealing process was used to heal these damages and to activate the dopants. In this study, we introduced several species such as alkali metals (Li, Na, K), alkali earth metals (Be, Ca,), transition metals (Ti, V, Cr, Mn) and other metals (Ga, Ge) into semiconductor substrates using ion implantation. The implantation energy varies form 70 keV to 200 keV and the dosages vary between ~ 1.0x1012 and ~5.0x1015 atoms/cm2. The samples are annealed at different temperatures from 300°C to 1000°C and for different time intervals. The redistribution behaviors of the implanted ions are studied experimentally using secondary ion mass spectrometry (SIMS). We observed some complex distribution behaviors due to the defects created during the process of ion implantation. The diffusivities of some impurities are calculated and compared to previous data. It was found that the diffusivities of implanted impurities is related to the dosages, annealing temperatures and the defects and damages caused by ion implantation. Additionally, as we go from one type of semiconductor to another, the diffusion behavior of the impurities shows a different trend.
| Identifer | oai:union.ndltd.org:ucf.edu/oai:stars.library.ucf.edu:etd-4329 |
| Date | 01 January 2007 |
| Creators | Salman, Fatma |
| Publisher | STARS |
| Source Sets | University of Central Florida |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | Electronic Theses and Dissertations |
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