Diffusion of Pb in carbon ion-implanted silicon: Discovery of a new crystalline phase after electron beam annealing

• Published in: Vacuum Vol. 82; no. 11; pp. 1306 - 1311
• Main Authors: Markwitz, Andreas, Baumann, Horst, Davy, Perry, Johnson, Peter B.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 19.06.2008
• Subjects: Electron beam annealing; Ion implantation; Novel Si xC yPb z phase; Pb diffusion; SiC nanocrystals; SiC nanocrystals; Ion implantation; Pb diffusion; Electron beam annealing; Novel Si x C y Pb z phase
• ISSN: 0042-207X; 1879-2715
• DOI: 10.1016/j.vacuum.2008.02.006

A novel phase has been discovered by dual low-energy ion implantation and high vacuum electron beam annealing. (100) p-type Si was implanted with (a) 20 keV 12C + ions to the fluence of 6 × 10 16 cm −2 and (b) 7 keV Pb + ions to the fluence of 4 × 10 15 cm −2. The 12C ion implantation results in an understoichiometric shallow SiC x layer that intersects with the surface. The implanted Pb ions decorate a shallow subsurface region. High vacuum electron beam annealing at 1000 °C for 15 s using a temperature gradient of 5 °C s −1 leads to the formation of large SiC nanocrystals on the surface with RBS measurements showing Pb has diffused into the deeper region affected by the 12C implantation. In this region, a new crystalline phase has been discovered by XRD measurements.