| dc.description.abstract | UV lithography and etching technology is developing in the direction of high productivity and high yield. However, the thickness of the interface diffusion layer of the Mo/Si mirror in the EUV lithography system seriously affects the optical quality of the mirror, which is an obstacle for the industry to move towards high productivity. However, the Mo/Si multilayers deposited by ion beam sputtering can effectively reduce the interface diffusion and reduce the roughness of each interface. In addition, this deposition technology can produce a minimum number of defects in the growth of the multilayers, so this technology has begun to attract attention.
Therefore, in this paper, the ion beam sputtering system was used to adjust the ion beam voltage and current at 60 ℃℃. First, Mo monolayer was deposited and Si thin film was deposited on Al2O3 or SiO2,and measured with ellipsometer to define the thickness of the monolayer. Next, two pairs of Mo/Si multilayers was deposited, firstly measured by XRR, and fitted with IMD software to obtain the multilayers structure information, and preliminarily judged the change trend of the interface thickness of the multilayers under the adjustment of various parameters, Finally, the effects of ion beam voltage and current on the microstructure were investigated through TEM cross-sectional measurement. It was found that decreasing the ion beam voltage can reduce the thickness of the interface diffusion layer, and the ion beam current must be selected to compromise the value to obtain the best interface performance. However, in TEM, the low electron absorptivity of Si material and the high electron absorptivity of Mo material lead to the discrepancy between the measured results of TEM film thickness and the fitting values of XRR. The AFM surface roughness results showed
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that the enhancement of ion beam voltage did not significantly change the surface roughness of the multilayers, and the enhancement of ion beam current could smooth the surface of the multilayers, indicating that the flux of ad atoms affected the surface roughness trend. | en_US |