Exotic Doping for Zno Thin Films: Possibility of Monolithic Optical Integrated Circuit

1999 ◽  
Vol 574 ◽  
Author(s):  
Norifumi Fujimura ◽  
Tamaki Shimura ◽  
Toshifumi Wakano ◽  
Atsushi Ashida ◽  
Taichiro Ito

AbstractWe propose the application of ZnO:X (X = Li, Mg, N, In, Al, Mn, Gd, Yb etc.) films for a monolithic Optical Integrated Circuit (OIC). Since ZnO exhibits excellent piezoelectric effect and has also electro-optic and nonlinear optic effects and the thin films are easily obtained, it has been studied as one of the important thin film wave guide materials especially for an acoustooptic device[1]. In terms of electro-optic and nonlinear optic effects, however, LiNbO3 or LiTaO3 is superior to ZnO. The most important issue of thin film waveguide using such ferroelectrics is optical losses at the film/substrate interface and the film surface, because the process window to control the surface morphology is very narrow due to their high deposition temperature. Since ZnO can be grown at extremely low temperature, the roughness at the surface and the interface is expected to be minimized. This is the absolute requirement especially for waveguide using a blue or ultraviolet laser. Recently, lasing at the wavelength of ultraviolet, ferroelectric and antiferromagnetic behaviors of ZnO doped with various exotic elements (exotic doping) have been reported. This paper discusses the OIC application of ZnO thin films doped with exotic elements.

2013 ◽  
Vol 1509 ◽  
Author(s):  
Akshta Rajan ◽  
Ayushi Paliwal ◽  
Vinay Gupta ◽  
Monika Tomar

ABSTRACTUltraviolet (UV) photoconductivity in pure ZnO thin films and metal (Ag, Au, Pt) nanoparticles (NPs) dispersed on ZnO thin films based UV photodetectors biased at 5 V for ultra violet radiation of λ = 365 nm and intensity = 24 µwatt/cm2 has been studied. All the three metal (Ag, Au, Pt) NPs synthesized by Polyol process when dispersed on the surface of 100 nm thin ZnO film results in enhanced photoconductive gain (K) in comparison to pure ZnO (3.1×103). An increase of about an order in K has been obtained in the case of Ag NPs/ZnO and Au NPs/ZnO UV photodetectors ( K = 6.9×104 and 5.3×104 respectively). On the other hand, Pt NPs enhance K by about two orders (5.0×105). Such an enhanced photoconductive gain has been achieved due to the lowering of dark current after dispersing the metal NPs on the surface of ZnO and increased photocurrent upon UV illumination. This may be attributed to the plasmon propagating property in metal NPs which enhances the light trapping through optical absorption in ZnO thin film surface (high photo current).


Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 397
Author(s):  
Yu-Chen Chang ◽  
Ying-Chung Chen ◽  
Bing-Rui Li ◽  
Wei-Che Shih ◽  
Jyun-Min Lin ◽  
...  

In this study, piezoelectric zinc oxide (ZnO) thin film was deposited on the Pt/Ti/SiNx/Si substrate to construct the FBAR device. The Pt/Ti multilayers were deposited on SiNx/Si as the bottom electrode and the Al thin film was deposited on the ZnO piezoelectric layer as the top electrode by a DC sputtering system. The ZnO thin film was deposited onto the Pt thin film by a radio frequency (RF) magnetron sputtering system. The cavity on back side for acoustic reflection of the FBAR device was achieved by KOH solution and reactive ion etching (RIE) processes. The crystalline structures and surface morphologies of the films were analyzed by X-ray diffraction (XRD) and field emission scanning electron microscope (FE-SEM). The optimized as-deposited ZnO thin films with preferred (002)-orientation were obtained under the sputtering power of 80 W and sputtering pressure of 20 mTorr. The crystalline characteristics of ZnO thin films and the frequency responses of the FBAR devices can be improved by using the rapid thermal annealing (RTA) process. The optimized annealing temperature and annealing time are 400 °C and 10 min, respectively. Finally, the FBAR devices with structure of Al/ZnO/Pt/Ti/SiNx/Si were fabricated. The frequency responses showed that the return loss of the FBAR device with RTA annealing was improved from −24.07 to −34.66 dB, and the electromechanical coupling coefficient (kt2) was improved from 1.73% to 3.02% with the resonance frequency of around 3.4 GHz.


2006 ◽  
Vol 21 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Lili Hu ◽  
Junlan Wang ◽  
Zijian Li ◽  
Shuang Li ◽  
Yushan Yan

Nanoporous silica zeolite thin films are promising candidates for future generation low-dielectric constant (low-k) materials. During the integration with metal interconnects, residual stresses resulting from the packaging processes may cause the low-k thin films to fracture or delaminate from the substrates. To achieve high-quality low-k zeolite thin films, it is important to carefully evaluate their adhesion performance. In this paper, a previously reported laser spallation technique is modified to investigate the interfacial adhesion of zeolite thin film-Si substrate interfaces fabricated using three different methods: spin-on, seeded growth, and in situ growth. The experimental results reported here show that seeded growth generates films with the highest measured adhesion strength (801 ± 68 MPa), followed by the in situ growth (324 ± 17 MPa), then by the spin-on (111 ± 29 MPa). The influence of the deposition method on film–substrate adhesion is discussed. This is the first time that the interfacial strength of zeolite thin films-Si substrates has been quantitatively evaluated. This paper is of great significance for the future applications of low-k zeolite thin film materials.


2014 ◽  
Vol 895 ◽  
pp. 41-44
Author(s):  
Seiw Yen Tho ◽  
Kamarulazizi Ibrahim

In this work, the influences of plasma pre-treatment on polyethylene terephthalate (PET) substrate to the properties of ZnO thin film have been carried out. ZnO thin films were successfully grown on PET substrate by spin coating method. In order to study the effects of plasma pre-treatment, a comparison of treated and untreated condition was employed. Water contact angle measurement had been carried out for PET wettability study prior to ZnO thin film coating. Morphology study of ZnO thin film was performed by scanning probe microscope (SPM). Besides, optical study of the ZnO thin film was done by using UV-vis spectrophotometer. All the measured results show that plasma pre-treatment of PET substrate plays an important role in enhancing the wettability of PET and optical properties of the ZnO thin films. In conclusion, pre-treatment of PET surface is essential to produce higher quality ZnO thin film on this particular substrate in which would pave the way for the integration of future devices.


2008 ◽  
Vol 2008 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammad Hossein Habibi ◽  
Mohammad Khaledi Sardashti

Glass plate-supported nanostructure ZnO thin films were deposited by sol-gel spin coating. Films were preheated at275∘Cfor 10 minutes and annealed at 350, 450, and550∘Cfor 80 minutes. The ZnO thin films were transparent ca 80–90% in visible range and revealed that absorption edges at about 370 nm. Thec-axis orientation improves and the grain size increases which was indicated by an increase in intensity of the (002) peak at34.4∘in XRD corresponding to the hexagonal ZnO crystal. The photocatalytic degradation of X6G an anionic monoazo dye, in aqueous solutions, was investigated and the effects of some operational parameters such as the number of layer and reusability of ZnO nanostructure thin film were examined. The results showed that the five-layer coated glass surfaces have a very high photocatalytic performance.


2021 ◽  
Vol 902 ◽  
pp. 65-70
Author(s):  
Samar Aboulhadeed ◽  
Mohsen Ghali ◽  
Mohamad M. Ayad

We report on a development of the structural, optical and electrical properties of poly (3,4-ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) conducting polymer thin films. The PEDOT:PSS thin films were deposited by a controlled thin film applicator and their physical properties were found to be effectively modified by isopropanol. The deposited films were investigated by several techniques including XRD, UV–Vis, SPM and Hall-effect. Interestingly, by optimizing the PEDOTS:PSS/ISO volume ratio (v:v), we find that the film charge carriers type can be switched from p to n-type with a high bulk carriers concentration reaching 6×1017 cm-3. Moreover, the film surface roughness becomes smoother and reaching a small value of only 1.9 nm. Such development of the PEDOT:PSS film properties makes it very promising to act as an electron transport layer for different energy applications.


1998 ◽  
Vol 13 (5) ◽  
pp. 1266-1270 ◽  
Author(s):  
Ai-Li Ding ◽  
Wei-Gen Luo ◽  
P. S. Qiu ◽  
J. W. Feng ◽  
R. T. Zhang

PLT(28) thin films deposited on glass substrates were studied by two sputtering processes. One is an in situ magnetron sputtering and the other is a low-temperature magnetron sputtering. The sintered PLT ceramic powders are used as a sputtering target for both processes. The influences of sputtering and annealing conditions on structure and crystallinity of the films were investigated. The electro-optic (E-O) properties of PLT(28) thin films prepared by the two processes were determined by a technique according to Faraday effect. The researches showed the E-O properties were strongly affected by the sputtering process. The film with larger grains exhibits stronger E-O effect. The quadratic E-O coefficient of PLT(28) thin film varies in the range of 0.1 × 10−16 to 1.0 × 10−16 (m/v)2.


10.14311/1767 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Jan Píchal ◽  
Julia Klenko

Thin film technology has become pervasive in many applications in recent years, but it remains difficult to select the best deposition technique. A further consideration is that, due to ecological demands, we are forced to search for environmentally benign methods. One such method might be the application of cold plasmas, and there has already been a rapid growth in studies of cold plasma techniques. Plasma technologies operating at atmospheric pressure have been attracting increasing attention. The easiest way to obtain low temperature plasma at atmospheric pressure seems to be through atmospheric dielectric barrier discharge (ADBD). We used the plasma enhanced chemical vapour deposition (PECVD) method applying atmospheric dielectric barrier discharge (ADBD) plasmafor TiOx thin films deposition, employing titanium isopropoxide (TTIP) and oxygen as reactants, and argon as a working gas. ADBD was operated in filamentary mode. The films were deposited on glass. We studied the quality of the deposited TiOx thin film surface for various precursor gas inlet positions in the ADBD reactor. The best thin films quality was achieved when the precursor gases were brought close to the substrate surface directly through the inlet placed in one of the electrodes.High hydrophilicity of the samples was proved by contact angle tests (CA). The film morphology was tested by atomic force microscopy (AFM). The thickness of the thin films varied in the range of (80 ÷ 210) nm in dependence on the composition of the reactor atmosphere. XPS analyses indicate that composition of the films is more like the composition of TiOxCy.


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.


2011 ◽  
Vol 25 (20) ◽  
pp. 2741-2749 ◽  
Author(s):  
J. C. ZHOU ◽  
L. LI ◽  
L. Y. RONG ◽  
B. X. ZHAO ◽  
Y. M. CHEN ◽  
...  

High transparency and conductivity of transparent conducting oxide thin film are very important for improving the efficiency of solar cells. ZnO thin film is a better candidate for transparent conductive layer of solar cell. N-type ZnO thin films were prepared by radio-frequency magnetron sputtering on glass substrates. ZnO thin films underwent annealing treatment after deposition. The influence of the sputtering power on the surface morphology, the electrical and optical properties were studied by AFM, XRD, UV2450 and HMS-3000. The experimental results indicate that the crystal quality of ZnO thin film is improved and all films show higher c-axis orientation with increasing sputtering power from 50 to 125 W. The average transparency of ZnO thin films is higher than 90% in the range of 400–900 nm between the sputtering power of 50–100 W. After the rapid thermal annealing at 550°C for 300 s under N2 ambient, the minimum resistivity reach to 10-2Ω⋅ cm .


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