This study reports a laser annealing technique to activate dopants in Si for semiconductor application. In this study, a CW laser of 532 nm was used to anneal the phosphorus (P) doped Si wafer, and the effects of laser power and scan speed on electrical, microstructural and chemical characteristics of the P-doped Si were investigated. It was found that the amorphized Si during the dopant implantation process was successfully recrystallized to either polycrystalline Si or single crystal Si by laser annealing. The sheet resistance decreased with increasing laser power or decreasing scan speed due to the improved crystallinty of Si. The full epitaxial growth of Si was achieved by inducing the complete melting of the amorphized Si, and under the this condition, a minimum sheet resistance was obtained. According to the dopant concentration analysis, it was found that dopant diffusion to the depth direction was very limited. The redistribution of dopants was only generated near the shallow surface region. As a result, relatively uniform concentration of the dopant was achieved, which is advantageous for the formation of the sallow junction. The results of this study show that the potential benefits of the laser annealing technique for improving the properties of semiconductor materials. Further research to explore various characteristics of the laser annealed Si is in progress.
Keywords
- Dopant Activation
- Epitaxial Growth
- Laser Annealing
- Sheet Resistance
- Si