Synthesis and characterization of large-grain solid-phase crystallized polycrystalline silicon thin films

n-type polycrystalline silicon (poly-Si) films with very large grains, exceeding 30 mu m in width, and with high Hall mobility of about 71.5 cm(2)/V s are successfully prepared by the solid-phase crystallization technique on glass through the control of the PH3 (2% in H-2)/SiH4 gas flow ratio. The effect of this gas flow ratio on the electronic and structural quality of the n-type poly-Si thin film is systematically investigated using Hall effect measurements, Raman microscopy, and electron back-scatter diffraction (EBSD), respectively. The poly-Si grains are found to be randomly oriented, whereby the average area weighted grain size is found to increase from 4.3 to 18 mu m with increase of the PH3 (2% in H-2)/SiH4 gas flow ratio. The stress in the poly-Si thin films is found to increase above 900 MPa when the PH3 (2% in H-2)/SiH4 gas flow ratio is increased from 0.025 to 0.45. Finally, high-resolution transmission electron microscopy, high angle annular dark field-scanning tunneling microscopy, and EBSD are used to identify the defects and dislocations caused by the stress in the fabricated poly-Si films. (C) 2014 American Vacuum Society.