Effects of substrate temperature on structural, optical and morphological properties of hydrogenated nanocrystalline silicon thin films prepared by inductively coupled plasma chemical vapor deposition

Abstract

Hydrogenated nanocrystalline silicon (nc-Si:H) thin films were deposited on glass substrate by inductively coupled plasma chemical vapor deposition technique in this paper. The structural, optical, and morphological properties of samples were investigated and found to be strongly dependent on the substrate temperature. X-ray diffraction patterns show silicon film deposited at 25 °C is almost entirely amorphous, however, as the substrate temperature increased from 100 to 300 °C, the grain size of samples increases from 4.1 to 14.6 nm indicates improved crystalline quality. Raman spectroscopy revealed the nc-Si:H films contain crystalline, amorphous and an intermediate structure, and the crystallinity of sample deposited at 300 °C reaching a maximum value of 56 %. The optical absorption spectra of nc-Si:H films show hydrogen content and quantum confinement effect have strong influence on the optical band gap. Atomic force microscopy images show good coincidence with above results.