The influence of structure variation on the 1/f noise of nanometric boron doped hydrogenated polymorphous silicon (pm-Si:H) films was investigated. The films were grown by the conventional radio frequency plasma enhanced chemical vapor deposition (PECVD) method. Raman spectroscopy was used to reveal the crystalline volume fraction (X(c)) and crystal size of the pm-Si:H. The measurement of optical and structure properties was carried out with spectroscopic ellipsometry (SE) in the Tauc-Lorentz model. A Fourier transform infrared (FTIR) spectrometer was used to characterize the presence of nanostructure-sized silicon clusters in pm-Si:H film deposited on KBr substrate. The electrical properties of the films were measured using evaporated coplanar nickel as the electrode. A semiconductor system was designed to obtain the 1/f noise of pm-Si:H film as well as that of amorphous and microcrystalline silicon films. The results demonstrate that the 1/f noise of pm-Si:H is nearly as low as that of microcrystalline silicon and much lower than that of amorphous silicon. The disorder to order transition mechanism of crystallization was used to analyze the decrease of noise compared with amorphous silicon.

Microcrystalline, polymorphous and amorphous silicon films were deposited in a standard radio frequency (rf) plasma enhanced chemical vapour deposition system at a high growth rate by using pure silane as source gas. The influence of thermal gradient variation on the growth model of the hydrogenated silicon film was investigated. The structure and optical properties of these silicon samples were characterized by Raman spectroscopy, spectroscopic ellipsometry and Fourier transform infrared spectrometry. The phase state at the boundary of the deposited silicon films was analysed using ion drag and plasma-induced thermophoresis on particles in a rf glow discharge. The results showed that control of the thermal gradient allows a switch from polymorphous to microcrystalline silicon growth. The crystalline volume fraction increases with increasing film thickness, and this demonstrates that there is a crystalline gradient between the surface and the bottom of the microcrystalline silicon film.

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The effects of 1.0 MeV electron irradiation on the dark conductivity and amorphous network of heavily phosphorus-doped a-Si : H films have been studied. The electron irradiation leads to a strong decrease by about two orders of magnitude in the dark conductivity of heavily phosphorus-doped a-Si : H films and the degradation comes to a saturation. The evolutions of the amorphous silicon network of heavily doped a-Si : H films caused by electron irradiation were investigated by Raman spectroscopy. The observed decrease in the amorphous silicon network order in the short and intermediate range suggests that the electron irradiation induces structural defects in the films. This defect creation also tends to saturate after a long irradiation time.