Microstructure of N+ ion beam induced epitaxial crystallized Si

Ion beam induced epitaxial crystallization of 300-350 nm thick amorphous Si by I MeV N+ ions in the temperature range of 200-400 degreesC was investigated. The dynamic thickness recovery as a function of temperature was observed using Rutherford backscattering spectrometry-channeling. The regrowth rate showed Arrhenius behavior with an activation energy of 0.29 +/- 0.03 eV. Using micro-Raman Spectroscopy the crystalline Si peak at 521 cm(-1) was found to decrease, broaden and shift to the lower wave numbers as the temperature decreased from 400 to 200 degreesC. The bond angle deviation below 3.5degrees suggests the phase change from amorphous to crystalline structure during ion beam induced recovery process. The asymmetric broadening of the Raman peaks at 250 and 300 degreesC along with TEM micrograph indicates the coexistence of nano-crystalline structures embedded in the amorphous Si matrix. (C) 2003 Elsevier B.V. All rights reserved.