scholarly journals Effect of Oxygen Partial Pressure on Crystal Structure, Oxygen Vacancy, and Surface Morphology of Epitaxial SrTiO3 Thin Films Grown by Ion Beam Sputter Deposition

Oxygen ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 62-72
Author(s):  
Gasidit Panomsuwan ◽  
Nagahiro Saito

Epitaxial SrTiO3 (STO) thin films were grown on (001)-oriented LaAlO3 (LAO) substrates at 800 °C by an ion beam sputter deposition (IBSD). Oxygen partial pressure (PO2) was varied at 1.5 × 10−5, 1.5 × 10−4, and 1.5 × 10−3 Torr during the growth. The effects of PO2 on crystal structure, oxygen vacancy, and surface morphology of the STO films were investigated and are discussed to understand their correlation. It was found that PO2 played a significant role in influencing the crystal structure, oxygen vacancy, and surface morphology of the STO films. All STO films grew on the LAO substrates under a compressive strain along an in-plane direction (a- and b-axes) and a tensile strain along the growth direction (c-axis). The crystalline quality of STO films was slightly improved at higher PO2. Oxygen vacancy was favorably created in the STO lattice grown at low PO2 due to a lack of oxygen during growth and became suppressed at high PO2. The existence of oxygen vacancy could result in a lattice expansion in both out-of-plane and in-plane directions due to the presence of Ti3+ instead of Ti4+ ions. The surface roughness of the STO films gradually decreased and was nearly close to that of the bare LAO substrate at high PO2, indicating a two-dimensional (2D) growth mode. The results presented in this work provide a correlation among crystal structure, oxygen vacancy, and surface morphology of the epitaxial STO films grown by IBSD, which form a useful guideline for further study.

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jin-Cherng Hsu ◽  
Yueh-Sheng Chiang

In this study, zinc oxide films were deposited by an ion-beam sputter deposition in various oxygen partial pressures at room temperature. The films changed the structures from amorphous to polycrystalline with increasing the oxygen partial pressure (). The optimal was found at Torr because the film prepared at the oxygen partial pressure had the lowest resistivity and the highest transparence in the visible light region. The lowest resistivity results from a great number of oxygen vacancy sites formed on the polycrystalline surface as exposed to the atmosphere. Moreover, the film has the highest XRD peak intensity, smallest FWHM diffraction peak, smallest -spacing, and smallest biaxial stress.


1983 ◽  
Vol 35 (1-3) ◽  
pp. 89-92 ◽  
Author(s):  
J.W. Smits ◽  
H.A. Algra ◽  
U. Enz ◽  
R.P. van Stapele

1991 ◽  
Vol 116 (1) ◽  
pp. 35-49 ◽  
Author(s):  
Angus Kingon ◽  
Michael Ameen ◽  
Orlando Auciello ◽  
Kenneth Gifford ◽  
Husam Al-Shareef ◽  
...  

2013 ◽  
Vol 25 (2) ◽  
pp. 772-777 ◽  
Author(s):  
Saurabh Kumar Pandey ◽  
Sushil Kumar Pandey ◽  
Vishnu Awasthi ◽  
Ashish Kumar ◽  
M. Gupta ◽  
...  

2008 ◽  
Vol 73 (1) ◽  
pp. 121-126
Author(s):  
Ivan Radovic ◽  
Yves Serruys ◽  
Yves Limoge ◽  
Natasa Bibic

SiO2 layers were deposited in a UHV chamber by 1 keV Ar+ ion sputtering from a high purity silicon target, using different values of the oxygen partial pressure (5?10-6-2?10-4 mbar) and of the ion beam current on the target (1.67-6.85 mA). The argon partial pressure during operation of the ion gun was 1?10-3 mbar. The substrate temperature was held at 550?C and the films were deposited to a thickness of 12.5-150 nm, at a rate from 0.0018-0.035 nm s-1. Structural characterization of the deposited thin films was performed by Rutherford backscattering spectrometry (RBS analysis). Reactive sputtering was proved to be efficient for the deposition of silica at 550?C, an oxygen partial pressure of 2?10-4 mbar (ion beam current on the target of 5 mA) or, at a lower deposition rate, ion beam current of 1.67 mA and an oxygen partial pressure of 6?10-5 mbar. One aspect of these investigations was to study the consumption of oxygen from the gas cylinder, which was found to be lower for higher deposition rates.


2015 ◽  
Vol 283 ◽  
pp. 241-246 ◽  
Author(s):  
Wei Mao ◽  
Masaya Fujita ◽  
Takumi Chikada ◽  
Kenji Yamaguchi ◽  
Akihiro Suzuki ◽  
...  

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