Effect of Substrate Temperature on Crystallization of Amorphous Antimony Film

Abstract

A study is made of the crystallization of amorphous antimony film deposited on a glass substrate. The substrate is maintained at a desired temperature between 20°C and 90°C. The crystal growth in the films of thickness 210-550 Å is directly observed through an optical microscope. At any substrate temperature Ts the rate of crystal growth v is found to change with the thickness d in accordance with the expression v=v∞(1-dc/d), where dc is the critical thickness for crystallization of the amorphous antimony film and v∞ the rate of crystal growth for bulk antimony. The critical thickness dc decreases with the rise of Ts. The activation energy of atoms for crystallization Q is found to be 0.32 eV for bulk antimony.

Refractive indices change at 633 nm of antimony thin films prepared by heliconwave-plasma sputtering method

“…1 It is known from previous works that amorphous Sb transforms into a crystalline state at a critical thickness that depends on the film preparation condition. 1,[5][6][7] This Sb film thickness is estimated to be around 15-30 nm when it is deposited at room temperature 6 and is nearly the same with the typical value of 15 nm that is used in the disk structure. 1,2 A systematic study on the relationship between the refractive index and film preparation condition is therefore necessary to further understand the function of Sb layer.…”

“…This may partly due to deviation of the film thickness from the expected value and/or some oxidation effects of Sb film with no protective layer. It is known that Sb crystallization depends strongly on the film preparation condition [5][6][7] and this may give arise some variation particularly for thin films, close to the critical thickness. However, besides this variation, trends of index change found in Fig.…”

“…An E a value of 2.4 eV is high compared to the previous reports with 0.3-1.8 eV for Sb crystallization. 6,7 The deviation may arise from the difference on the film thickness since E a increases as thickness becomes thinner than 100 nm. 6 A similar E a value of 2.0 eV was obtained for Sb particle with its diameter of 10 nm.…”

“…Former low k values are close to 1.74 for amorphous Sb at 650 nm 8 and latter ones are close to about 5.0 for crystalline Sb at 632.8 nm. 9 Also from previous works on crystallization of Sb films, [5][6][7] it is expected that the index change is due to the phase change from amorphous to crystalline state. As d Sb further increased from 15 to 100 nm, the coefficient k for samples prepared at 0.2 Pa almost remained a constant of 5.5.…”

Crystallization of supercooled liquid antimony: A density functional study

“…Similar simulations of Sb and GeSb compounds (144 atoms, cubic templates) by Hegedüs and Elliott found metastable cubic phases [10], and simulations of Sb with an A7 template indicated the initial formation of crystals with an unusual layer structure. Experimental crystallization studies have included the roles of film thickness [11], deposition rate [3], gas pressure [3,12], and temperature [13,14].…”