Elipsometric study of polycrystalline silicon films prepared by low pressure chemical vapor deposition
JournalName :
J. Appl. Phys.
PubDateYear :
2000
PubDateOther :
Volume :
87
Issue :
StartPage :
1734
EndPage :
Keywords :
Notes :
Abstract :
Polysilicon layers with thicknesses between 8 and 600 nm deposited by low-pressure chemicalvapor deposition at temperatures ranging from 560 to 640 °C were characterized by spectroscopicellipsometry ~SE! to determine the layer thicknesses and compositions using multilayer opticalmodels and the Bruggeman effective-medium approximation. The dependence of the structuralparameters on the layer thickness and deposition temperature have been investigated. A bettercharacterization of the polysilicon layer is achieved by using the reference data of fine-grainedpolysilicon in the optical model. The amount of voids in the polysilicon layer was independentlymeasured by Rutherford backscattering spectrometry ~RBS!. The SE and RBS results show a goodcorrelation. The comparison of the surface roughness measured by SE and atomic force microscopy~AFM! shows that independently of the AFM window sizes, a good correlation of the roughnessdetermined by SE and AFM was obtained.
