|
|
Fabrication processing effects on microstructure and morphology of erbium film
Shen Hua-Hai(申华海), Peng Shu-Ming(彭述明), Long Xing-Gui(龙兴贵), Zhou Xiao-Song(周晓松), Yang Li(杨莉), Liu Jin-Hua(刘锦华), Sun Qing-Qiang(孙庆强), and Zu Xiao-Tao(祖小涛)
Chin. Phys. B, 2012, 21 (7):
076101.
DOI: 10.1088/1674-1056/21/7/076101
The effects of substrate temperature on the microstructure and the morphology of erbium film are systematically investigated by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). All the erbium films are grown by the electron-beam vapor deposition (EBVD). A novel preparation method for observing the cross-section morphology of the erbium film is developed. The films deposited at 200 ℃ have (002) preferred orientation, and the films deposited at 450 ℃ have mixed (100) and (101) texture, which are due to the different growth mechanisms of surface energy minimization and recrystallization, respectively. The peak positions and the full widths at half maximum (FWHMs) of erbium diffraction lines (100), (002), and (101) shift towards higher angles and decrease with the increasing substrate temperature in a largely uniform manner, respectively. Also, the lattice constants decrease with the increasing temperature. The transition in the film stresses can be used to interpret the changes in peak positions, FWHMs, and lattice constants. The stress is compressive for the as-growth films, and is counteracted by the tensile stress formed during the process of temperature cooling down to room temperature. The tensile stress mainly originates from the difference in the coefficients of thermal expansion of substrate--film couple.
|
