微晶Si_(1-x)C_x:F:H薄膜X衍射和XPS研究

用PECVD法分解SiH_4,CF_4,PH_3和H_2混合气体制备电导性能良好的磷重掺杂微晶Si_(1-x)C_x:F:H薄膜;薄膜的X衍射谱表明其结构为非晶-微晶两相混合结构;膜中C的XPS峰表现为F键合C和无F键合C两种信号的叠加;F键合c含量增大时,薄膜电导率迅速下降。文中提出了薄膜结构模型及能带模型。

X-Ray Diffraction and XPS Studies on Microcrystalline Si_(1-x)C_x:F:H Films

Heavily phosphor-doped microcrystalline Si1-xCx:F:H films are pre-pared from silance,tetrafluoride-carbon,phosphine and hydrongen gas mixtures by RF PECVD. The X-ray diffraction spectra reveal that the structures of the films are amorphouse-microcrystalline mixed phases. Based on this,a simplified microstruc-ture model and a energy band model for the films are proposed. The XPS peaks of C15 can be reasonably considered as a superposition of a higher binding-energy signal and a lower binding-energy one,which originate from carbons bonding with and without fluor. When the fluor-bonded carbon increases , the conductivity of the films decreases rapidly.