Physical Characterization of Thin Films of Lithium Niobate Deposited on Silicon Substrates

1990 ◽  
Vol 200 ◽  
Author(s):  
Robert C. Baumann ◽  
Timothy A. Rost ◽  
Thomas A. Rabson

ABSTRACTThin films (.1-.6 μm) of LiNbO3 have been deposited on silicon substrates by reactive rf sputtering. Under optimized deposition conditions the resulting thin films of LiNbO3 were optically transparent, adhered well to the silicon substrates, and were found to be polycrystalline and uniaxial with the c axis oriented normal to the silicon surface. Optical microscopy and scanning electron microscopy were used to examine film morphology. Both methods indicated that the films were smooth and contained no gross irregularities. The ratio of oxygen to niobium in these films was measured by Rutherford backscattering to be approximately 3 to 1. Auger electron spectroscopy depth profiling revealed that the films had the expected ratio of Li, Nb, and O. This information, together with Bragg x-ray diffraction data, indicates that the thin films deposited on silicon were stoichiometric, crystalline LiNbO3.

1994 ◽  
Vol 343 ◽  
Author(s):  
P. F. Baude ◽  
J. S. Wright ◽  
C. Ye ◽  
L. F. Francis ◽  
D. L. Polla

ABSTRACT(PbBa)(ZrTiNb)03 thin films and powders have been prepared using the sol-gel technique. Solutions were synthesized in 2-methoxyethanol based upon our previous PZT solution preparation. Three different approaches were used for incorporating barium into PZT alkoxide solutions. Thermal analysis and x-ray diffraction results indicated that barium methoxypropoxide gave the best results. PBZTN (71% Pb and 71% Zr) was deposited onto sapphire substrates as well as oxidized silicon substrates. Optical transmission measurements showed greater than 80% transmission for wavelengths longer than 400 nm. Films with thickness of 3000 Å on sapphire exhibited a refractive index of 2.19 at λ=633 nm.


1994 ◽  
Vol 361 ◽  
Author(s):  
Y. Gao ◽  
W. Dong ◽  
B.A. Turtle

ABSTRACTFerroelectric PbTiO3 and Pb(Zr,Ti)O3 thin films with a perovskite structure were grown on MgO and Pt/Ti/SiO2/Si by MOCV.D. The microstructure and composition of the films were characterized by x-ray diffraction, SEM, and AES. Preferred orientation of either (111) or (100)/(001) was obtained on the Pt/Ti/SiO2/Si substrates at temperatures from 600 °C to 650 °C The preferred (111) orientation was attributed to the formation of the Pt3Ti phase in the Pt layer of the substrates, whereas the (100)/(001) orientations were inferred as the growth rate effect. AES depth profiling indicated a uniform composition through the thickness of the PZT films. However, SEM showed different topography and microstructure of the PZT films deposited in different oxygen partial pressure. Electrical properties of the PZT films appear varied as a function of the oxygen partial pressure in the reactor.


2013 ◽  
Vol 665 ◽  
pp. 254-262 ◽  
Author(s):  
J.R. Rathod ◽  
Haresh S. Patel ◽  
K.D. Patel ◽  
V.M. Pathak

Group II-VI compounds have been investigated largely in last two decades due to their interesting optoelectronic properties. ZnTe, a member of this family, possesses a bandgap around 2.26eV. This material is now a day investigated in thin film form due to its potential towards various viable applications. In this paper, the authors report their investigations on the preparation of ZnTe thin films using vacuum evaporation technique and their structural and optical characterizations. The structural characterization, carried out using an X-ray diffraction (XRD) technique shows that ZnTe used in present case possesses a cubic structure. Using the same data, the micro strain and dislocation density were evaluated and found to be around 1.465×10-3lines-m2and 1.639×1015lines/m2respecctively. The optical characterization carried out in UV-VIS-NIR region reveals the fact that band gap of ZnTe is around 2.2eV in present case. In addition to this, it was observed that the value of bandgap decreases as the thickness of films increases. The direct transitions of the carries are involved in ZnTe. Using the data of UV-VIS-NIR spectroscopy, the transmission coefficient and extinction coefficient were also calculated for ZnTe thin films. Besides, the variation of extinction coefficient with wavelength has also been discussed here.


1990 ◽  
Vol 37 (1) ◽  
pp. 141-144
Author(s):  
Tsunekazu Iwata ◽  
Akihiko Yamaji ◽  
Youichi Enomoto

2005 ◽  
Vol 892 ◽  
Author(s):  
Qianghua Wang ◽  
Jianzeng Xu ◽  
Changhe Huang ◽  
Gregory W Auner

AbstractThis paper reports the fabrication and characterization of micromachined ultrasonic transducers (MUT) based on piezoelectric aluminum nitride (AlN) thin films. The MUT device is composed of an Al/AlN/Al sandwiched structure overlaid on top of a silicon (Si) diaphragm. X-ray diffraction (XRD) scan shows that highly c-axis oriented AlN (002) thin films have been grown on Al/Si(100) substrates. Electrical impedance of the MUT devices is analyzed as a function of frequency. The fundamental resonant frequencies of the devices are found in the range of 65-70 kHz, which are in approximation to the theoretical calculation. The effective coupling factors of the devices are also derived as 0.18.


1988 ◽  
Vol 32 ◽  
pp. 311-321 ◽  
Author(s):  
R.A. Larsen ◽  
T.F. McNulty ◽  
R.P. Goehner ◽  
K.R. Crystal

AbstractThe use of conventional θ/2θ diffraction methods for the characterization of polycrystalline thin films is not in general a satisfactory technique due to the relatively deep penetration of x-ray photons in most materials. Glancing incidence diffraction (GID) can compensate for the penetration problems inherent in the θ/2θ geometry. Parallel beam geometry has been developed in conjunction with GID to eliminate the focusing aberrations encountered when performing these types of measurements. During the past yearwe developed a parallel beam attachment which we have successfully configured to a number of systems.


2007 ◽  
Vol 546-549 ◽  
pp. 1699-1702
Author(s):  
Xi Ying Zhou ◽  
Liang He ◽  
Yan Hui Liu

Al-Cu-Fe quasicrystals powder was used to prepare the thin films on the surface of the A3 steel by the means of DMD-450 vacuum evaporation equipment. The thin films with different characterization were obtained through different parameters. The microstructures of the thin films were analyzed by Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). Additionally, the nano-hardness and the modulus of the films are tested by MTS and Neophot micro-hardness meter. The results showed that the modulus of the films was about 160GPa. Nano hardness of the films was about 7.5 Gpa. The films consisted of CuAl2, AlCu3. The thickness and the micro-hardness of the films are improved. In same way, with the increase of the electric current, the thickness and the hardness of the films are also improved. Along with increase of the time and the electric current, the wear behavior of the films was improved. To some extent, the microstructure of films contained the quasicrystal phase of Al65Cu20Fe15.


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