AVS 61st International Symposium & Exhibition
    Thin Film Thursday Sessions
       Session TF-ThP

Paper TF-ThP4
Improved Reflectance of M/Si Bilayers for Extreme Ultraviolet Lithography Reflective Mirror

Thursday, November 13, 2014, 6:00 pm, Room Hall D

Session: Thin Films Poster Session
Presenter: Chao-Te Lee, National Applied Research Laboratories, Taiwan, Republic of China
Authors: C.-T. Lee, National Applied Research Laboratories, Taiwan, Republic of China
D. Chiang, National Applied Research Laboratories, Taiwan, Republic of China
P.-K. Chiu, National Applied Research Laboratories, Taiwan, Republic of China
H.-P. Chen, National Applied Research Laboratories, Taiwan, Republic of China
C.N. Hsiao, National Applied Research Laboratories, Taiwan, Republic of China
Correspondent: Click to Email
The periodic Mo/Si bilayers were deposited on Si substrate by RF magnetron sputtering with Mo and Si targets. The Mo/Si bilayers were designed for reflectivity at the wavelength of 13.5 nm. The effects of substrate temperature range ( T=20 to 25 ℃, and 20 to 55℃) on the microstructure, surface roughness and reflectance of Mo/Si bilayers were investigated by atomic force microscopy (AFM), high resolution transmission electron microscopy (HRTEM), and a spectrometer. The AFM measurements showed the Mo/Si bilayers to have a uniform morphology with a very low surface roughness value under 0.2 nm. It was found that the interface between Mo and Si film was clearly discriminated at substrate temperature range 20 to 25 ℃ by HRTEM. The reflectivity of Mo/Si bilayers was 47.9% at substrate temperature range 20 to 55 ℃, and 63.3% at substrate temperature range 20 to 25 ℃, respectively. The incident angle increased from 33.47o to 46.13o with substrate temperature range. The improved reflectance and incident angle shifted were attributed to form the clearly interface and vary the film thickness.