Using the backscattering geometry micro Raman microscopy

the a:Si film which made by PECVD was crystallized

and measured by the same instrument. The laser power density was about 8.3×10

5

W/cm

2

when using 100×objective (N. A.=0.9) and 6.1×10

5

W/cm

2

when using 50×objective( N. A.=0.75) to crystallizing. The wavelength of laser is 632.8nm (He-Ne laser). Based on the confocal Raman spectrometer and depth profile method

we collected the series of Raman spectrum of silicon film that the focus laser spot located the different depth in the amorphous silicon film when processing the laser crystallization. Through the Raman Stokes peak and anti Stokes peak of microcrystallite silicon film which have been laser crystallized

we can calculate the maximum temperature of the amorphous silicon film was about 1600K in the process of laser crystallized. At the same position on the sample

reduced the laser power density to about 6×10

4

W/cm

2

(the laser of this power density can not effect the character of the microcrystallite silicon film)

repeating the Raman depth profile experiment and getting the series of Raman spectrum. After curve fitting these Raman spectrum of the laser crystallized silicon film

the Raman spectrum mainly fit to five peak (crystal silicon peak about at 520cm

-1

amorphous peak about at 480cm

-1

and others three peaks)

we got the area of crystal silicon peak and amorphous silicon peak which attribute the degree of laser-crystallized and we discover crystalline phase located only in the middle of thin film. According to the Raman shift of the peak of crystal silicon

we estimated the size of crystal grain was about 5nm. By this way

the nanocrystal silicon material in the thin film have been achieved

and the character of crystalline phase in laser-crystallized poly-Si thin films has been researched.