The Optical and Crystalline Structure Properties of ZnO Thin Films Grown by Rf Magnetron Sputtering

1999 ◽  
Vol 560 ◽  
Author(s):  
K. K. Kim ◽  
S. J. Park ◽  
J.H. Song ◽  
J.-H. Song ◽  
H.-J. Jung ◽  
...  

ABSTRACTZnO thin films were epitaxially grown on A12O3 (0001) single crystalline substrate by RF magnetron sputtering. The films were grown at the substrate temperature of 550°C and 600°C for 1 h and at a power of 60–120 W. The crystalline structure of the ZnO films was analyzed by 4-circle X-ray diffraction and backscattering (BS)/channeling. The FWHM of XRD ø -rocking curve increase from 9.45 to 18 arc-min. as the RF power increased from 80 to 120 W at 550°C. In-plane ZnO growth on sapphire.(0001) substrate at 550°C and at 80 W was found to be ZnO [1010] |: A12O3[1120], indicating a 30° rotation of ZnO unit cell about the sapphire (0001) substrate. For a specimen that was grown at an RF power of 120 W, 550°C, 1 h, the FWHM of XRD ø -rocking curve was 7.79 arc-min. In BS/channeling studies, the films deposited at 120 W, 600°C showed good crystallinity with the channeling yield minimum (Xmin) of only 5%, but for films deposited at 550°C the yield was as high as 50-60%, was of lower crystalline qualilty. From the results of the AFM measurement, the grain size gradually increased as the growing temperature and power increased. In case of the film deposited at 120 W and 600°C. the hexagonal shape of the grains were clearly observed. In PL measurement, only the sharp near band edge (NBE) emission were observed at room temperature for the film deposited at 80-120 W and 550°C, but the emission from deep level were also detected in the films deposited at 60 W, 550°C and 120 W, 600°C. The FWFM was decreased from 133 meV to 89 meV as RF power increased from 80 to 120 W at 550°C, and that of film deposited at 120 W and 600°C showed 98 meV respectively. The results were somewhat opposite to those of XRD. In the present study, the relationship between optical properties and crystal structure is discussed in terms of the quality of grains and the defects.

2007 ◽  
Vol 336-338 ◽  
pp. 581-584
Author(s):  
Chong Mu Lee ◽  
Choong Mo Kim ◽  
Sook Joo Kim ◽  
Yun Kyu Park

ZnO thin films were deposited on sapphire (α-Al2O3) substrates by RF magnetron sputtering at substrate temperatures of 500, 600, 650 and 700°C for 3h at rf-powers ranging from 60 to 120 W. The FWHM of the XRD (0002) peak for the ZnO film was reduced down to 0.07° by optimizing the chamber pressure at a substrate temperature of 700°C. Sharp near-band-edge emission was observed in the photoluminescence (PL) spectrum for the ZnO film grown at room temperature. Excess RF power aggravates the crystallinity and the surface roughness of the ZnO thin film. Pole figure, AES and PL analysis results confirm us that RF magnetron sputtering offers ZnO films with a lower density of crystallographic defects. ZnO films with a high quality can be obtained by optimizing the substrate temperature, RF power, and pressure of the RF magnetron sputtering process.


2009 ◽  
Vol 1165 ◽  
Author(s):  
Luis Angelats-Silva ◽  
Maharaj S. Tomar ◽  
Oscar Perales-Perez ◽  
S. P. Singh ◽  
Segundo R. Jauregui-Rosas

AbstractWe report a systematic study of the influence of the target-substrate distance and rf power on the structural and optical properties of ZnO thin films grown by rf magnetron sputtering in Ar atmosphere from ZnO sputtering target. Sharp (002) peak showed by XRD indicates a c-axis crystalline growth of ZnO films. Growth rate remained almost constant for short target-substrate distances. However, the grain size increases with the rf power decreasing the compressive stress in ZnO films. As-grown ZnO films have average transmittance more than 80% in the visible region. Optical bandgap (Eg) increases from 3.18 to 3.27 eV as increase the target-substrate distance probably due to low stress compression in ZnO films. In addition, when rf power is above 100 W, the optical band gap increases as increase of the stress compression.


2008 ◽  
Vol 63 (9) ◽  
pp. 585-590
Author(s):  
Jayaraman Elanchezhiyan ◽  
Periyasamy Bhuvana ◽  
Nammalvar Gopalakrishnan ◽  
Arumugam Thamizhavel ◽  
Thailampillai Balasubramanian

We have investigated the effect of doping concentration on structural, optical and magnetic properties of Mn-doped ZnO thin films deposited on Si (100) substrate by RF magnetron sputtering. The films have been characterized by X-ray diffraction (XRD), photoluminescence (PL) and superconducting quantum interference device (SQUID) magnetometry. It is observed from XRD, that the increase of Mn content increases the FWHM which indicates the degradation of crystalline quality. The photoluminescence spectrum reveals that the incorporation of Mn ions suppresses the deep level emissions considerably in comparison to those observed in pure ZnO. The near band edge (NBE) emission of Mn-doped films is shifted to the lower energy side (red shift) in comparison to pure ZnO film. The room temperature SQUID magnetometer results reveal that all the films show paramagnetic behaviour due to the lack of interactions among Mn moments.


2012 ◽  
Vol 626 ◽  
pp. 168-172
Author(s):  
Samsiah Ahmad ◽  
Nor Diyana Md Sin ◽  
M.N. Berhan ◽  
Mohamad Rusop

Zinc Oxide (ZnO) thin films were deposited onto SiO2/Si substrates using radio frequency (RF) magnetron sputtering method as an Ammonia (NH3) sensor. The dependence of RF power (50~300 Watt) on the structural properties and sensitivity of NH3sensor were investigated. XRD analysis shows that regardless of the RF power, all samples display the preferred orientation on the (002) plane. The results show that the ZnO deposited at 200 Watt display the highest sensitivity value which is 44%.


2007 ◽  
Vol 21 (31) ◽  
pp. 5257-5263 ◽  
Author(s):  
S. W. XUE ◽  
X. T. ZU ◽  
X. XIANG ◽  
M. Y. CHEN ◽  
W. G. ZHENG

ZnO thin films were first prepared by the sol–gel process, and then Ge ions were implanted into the ZnO films. The effects of ion implantation on the structural and optical properties of the ZnO films were investigated by X-ray diffraction, photoluminescence (PL), and optical transmittance measurements. Measurement results showed that the intensity of the (002) diffraction peak was decreased and the full width at half maximum was narrowed. PL emission was greatly extinguished after Ge ion implantation. Both the near band edge (NBE) excitonic UV emission at 391 nm and the defect related deep level emission centered at 470 nm in the visible region were decreased after Ge ion implantation. NBE peak and the absorption edge were observed to have a blueshift toward higher energy.


2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao

ZnO thin films with different thickness (the sputtering time of AlN buffer layers was 0 min, 30 min,60 min, and 90 min, respectively) were prepared on Si substrates using radio frequency (RF) magnetron sputtering system.X-ray diffraction (XRD), atomic force microscope (AFM), Hall measurements setup (Hall) were used to analyze the structure, morphology and electrical properties of ZnO films.The results show that growth are still preferred (002) orientation of ZnO thin films with different sputtering time of AlN buffer layer,and for the better growth of ZnO films, the optimal sputtering time is 60 min.


2010 ◽  
Vol 10 (3) ◽  
pp. S463-S467 ◽  
Author(s):  
Kyu Ung Sim ◽  
Seung Wook Shin ◽  
A.V. Moholkar ◽  
Jae Ho Yun ◽  
Jong Ha Moon ◽  
...  

2011 ◽  
Vol 1288 ◽  
Author(s):  
Rashmi Menon ◽  
K. Sreenivas ◽  
Vinay Gupta

ABSTRACTZinc Oxide (ZnO), II-VI compound semiconductor, is a promising material for ultraviolet (UV) photon sensor applications due to its attractive properties such as good photoconductivity, ease processing at low temperatures and excellent radiation hardness. The rf magnetron sputtering is a suitable deposition technique due to better control over stoichiometry and deposition of uniform film. Studies have shown that the presence of surface defects in ZnO and subsequently their passivation are crucial for enhanced photo-response characteristics, and to obtain the fast response speed. Worldwide efforts are continuing to develop good quality ZnO thin films with novel design structures for realization of an efficient UV photon sensor. In the present work, UV photon sensor is fabricated using a ZnO thin films deposited by rf magnetron sputtering on the corning glass substrate. Photo-response, (Ion/Ioff) of as-grown ZnO film of thickness 100 nm is found to be 3×103 with response time of 90 ms for UV intensity of 140 μW/cm2 (λ = 365 nm). With irradiation on ZnO thin film by pulsed Nd:YAG laser (forth harmonics 266 nm), the sensitivity of the UV sensor is found to enhance. The photo-response increases after laser irradiation to 4x104 with a fast response speed of 35 ms and attributed to the change in surface states and the native defects in the ZnO thin film. Further, enhancement in the ultraviolet (UV) photo-response (8×104) of detector was observed after integrating the nano-scale islands of Sn metal on the surface of laser irradiated ZnO thin film.


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