Microcrystalline silicon (?c-Si) films are deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) starting from SiF4:H2-He plasmas. In this article, we present the structural, morfological, optical and electrical characterization of ?c-Si films deposited on glass by RF discharge under different growth conditions. The monitoring of the growth of ?c-Si films by Optical Emission Spectroscopy (OES) has provided evidence that the silicon structure can be changed from pure amorphous to pure microcrystalline under controlled variation of the relative densities of F atoms, H atoms and of SiFn radicals in the plasma phase. A detailed analysis of the anatomy of ?c-Si films is performed by Spectroscopic Ellipsometry (SE) and information on the effect of the growth precursors and of the type of substrate on the growth dynamics can be obtained. SE analysis has been corroborated by Standard Constant Photocurrent Method (S-CPM) measurements. No thickness effect on the ?true coefficient had been observed whereas the change in crystalline fraction results in different scattering effects.
Plasma enhanced chemical vapour deposition of µc-Si thin films: structure analysis
MM Giangregorio;M Ambrico;G Cicala;M Losurdo;
2000
Abstract
Microcrystalline silicon (?c-Si) films are deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) starting from SiF4:H2-He plasmas. In this article, we present the structural, morfological, optical and electrical characterization of ?c-Si films deposited on glass by RF discharge under different growth conditions. The monitoring of the growth of ?c-Si films by Optical Emission Spectroscopy (OES) has provided evidence that the silicon structure can be changed from pure amorphous to pure microcrystalline under controlled variation of the relative densities of F atoms, H atoms and of SiFn radicals in the plasma phase. A detailed analysis of the anatomy of ?c-Si films is performed by Spectroscopic Ellipsometry (SE) and information on the effect of the growth precursors and of the type of substrate on the growth dynamics can be obtained. SE analysis has been corroborated by Standard Constant Photocurrent Method (S-CPM) measurements. No thickness effect on the ?true coefficient had been observed whereas the change in crystalline fraction results in different scattering effects.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
