scholarly journals Postannealing Effect at Various Gas Ambients on Ohmic Contacts of Pt/ZnO Nanobilayers toward Ultraviolet Photodetectors

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Chung-Hua Chao ◽  
Mao-Yi Chen ◽  
Chii-Ruey Lin ◽  
Yueh-Chung Yu ◽  
Yeong-Der Yao ◽  
...  
Keyword(s):  
Thin Films ◽  
Gas Flow ◽  
Ohmic Contacts ◽  
Chemical Vapor ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
Flow Rate Ratio ◽  
Silicon Substrates ◽  
Pt Electrode ◽  
Ultraviolet Photodetectors

This paper describes a fabrication and characterization of ultraviolet (UV) photodetectors based on Ohmic contacts using Pt electrode onto the epitaxial ZnO (0002) thin film. Plasma enhanced chemical vapor deposition (PECVD) system was employed to deposit ZnO (0002) thin films onto silicon substrates, and radio-frequency (RF) magnetron sputtering was used to deposit Pt top electrode onto the ZnO thin films. The as-deposited Pt/ZnO nanobilayer samples were then annealed at450∘Cin two different ambients (argon and nitrogen) to obtain optimal Ohmic contacts. The crystal structure, surface morphology, optical properties, and wettability of ZnO thin films were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), photoluminescence (PL), UV-Vis-NIR spectrophotometer, and contact angle meter, respectively. Moreover, the photoconductivity of the Pt/ZnO nanobilayers was also investigated for UV photodetector application. The above results showed that the optimum ZnO sample was synthesized with gas flow rate ratio of 1 : 3 diethylzinc [DEZn, Zn(C2H5)2] to carbon dioxide (CO2) and then combined with Pt electrode annealed at450∘Cin argon ambient, exhibiting good crystallinity as well as UV photo responsibility.

Effects of the Sputtering Time of AlN Buffer Layer on the Quality of ZnO Thin Films

2014 ◽  
Vol 881-883 ◽  
pp. 1117-1121 ◽  
Author(s):  
Xiang Min Zhao
Keyword(s):  
Thin Films ◽  
Buffer Layer ◽  
Rf Magnetron Sputtering ◽  
Buffer Layers ◽  
Zno Thin Films ◽  
Zno Films ◽  
Si Substrates ◽  
Atomic Force ◽  
Structure Morphology ◽  
Aln Buffer

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.

Effects of dopant (Al, Ga, and In) on the characteristics of ZnO thin films prepared by RF magnetron sputtering system

2010 ◽  
Vol 10 (3) ◽  
pp. S463-S467 ◽  
Author(s):  
Kyu Ung Sim ◽  
Seung Wook Shin ◽  
A.V. Moholkar ◽  
Jae Ho Yun ◽  
Jong Ha Moon ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Rf Magnetron Sputtering ◽  
Zno Thin Films ◽  
Sputtering System

Effect of Nitrogen Doping on the Structure and Optical Properties of N-Type Hydrogenated Amorphous Silicon Thin Films

2011 ◽  
Vol 383-390 ◽  
pp. 6980-6985
Author(s):  
Mao Yang Wu ◽  
Wei Li ◽  
Jun Wei Fu ◽  
Yi Jiao Qiu ◽  
Ya Dong Jiang
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Amorphous Silicon ◽  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Silicon Thin Films ◽  
Frequency Plasma ◽  
Hydrogenated Amorphous

Hydrogenated amorphous silicon (a-Si:H) thin films doped with both Phosphor and Nitrogen are deposited by ratio frequency plasma enhanced chemical vapor deposition (PECVD). The effect of gas flow rate of ammonia (FrNH3) on the composition, microstructure and optical properties of the films has been investigated by X-ray photoelectron spectroscopy, Raman spectroscopy and ellipsometric spectra, respectively. The results show that with the increase of FrNH3, Si-N bonds appear while the short-range order deteriorate in the films. Besides, the optical properties of N-doped n-type a-Si:H thin films can be easily controlled in a PECVD system.

Characterizations and Process Parameters of Titanium Dioxide Thin Film by RF Sputtering

2013 ◽  
Vol 22 ◽  
pp. 9-21 ◽  
Author(s):  
Chii Rong Yang ◽  
Tun Ping Teng ◽  
Yun Yu Yeh
Keyword(s):  
Thin Films ◽  
Oxygen Content ◽  
Flow Rate ◽  
Gas Flow ◽  
Deposition Time ◽  
Photocatalytic Performance ◽  
Oxidation Process ◽  
Rf Sputtering ◽  
Rf Magnetron Sputtering ◽  
Oxygen Ratio

In this study, we successfully combined RF magnetron sputtering of a pure Ti metal target and one-stage oxidation process with a wider oxygen ratio (10%-90%) and total sputtering flow rate (16-24 sccm) to produce TiO2thin films on a glass substrate. The crystallization, morphology, roughness, and thickness of the thin films were examined using XRD, HR-FESEM, AFM, and a profilometer. Subsequently, the photocatalytic performance was examined using a spectrometer and video tensiometer. The experimental results show that the TiO2thin films with a majority of anatase and higher roughness exhibit superior photocatalytic performance; the total sputtering gas flow rate of 18 sccm and oxygen content at 10% is the optimal option. Finally, an empirical formula to correlate the film thickness with deposition time was conducted for the sputtering flow rate of 18 sccm and the oxygen content of 10%.

Raman Characterization of Doped 3C-SiC/Si for Different Silicon Substrates and C/Si Ratios

2010 ◽  
Vol 645-648 ◽  
pp. 255-258 ◽  
Author(s):  
Nicolò Piluso ◽  
Andrea Severino ◽  
Massimo Camarda ◽  
Ruggero Anzalone ◽  
Andrea Canino ◽  
...  
Keyword(s):  
Thin Films ◽  
Carrier Density ◽  
Gas Flow ◽  
Strong Relationship ◽  
Free Carrier ◽  
Silicon Substrates ◽  
Accurate Analysis ◽  
Si Substrates ◽  
Free Carrier Density ◽  
Longitudinal Optic Phonon

Raman microscopy has been used to study transport properties in hetero-epitaxial 3C-SiC/Si thin films. By an accurate analysis of the Longitudinal Optic phonon-plasmon coupled (LOPC) modes in n-type doped 3C-SiC films, free carrier density and mobility has been determined. A study of doped 3C-SiC reveals a strong relationship between the calculated free carrier density and both the C/Si ratio used during the epitaxial process and Silicon substrates orientation on which 3C-SiC thin films were grown (maintaining the N2 gas flow rate). The free carrier density obtained is in the range between 5x1016 cm-3 and 4x1018 cm-3. Epitaxial films grown on (111) Si substrates show a higher free carrier density and a lower dependence on C/Si ratios as compared to films grown on (100) Si substrates.

Measurement of The Activation Energy in Phosphorous Doped Polycrystalline Diamond Thin Films Grown on Silicon Substrates by Hot Filament Chemical Vapor Deposition

1996 ◽  
Vol 423 ◽  
Author(s):  
S. Mirzakuchaki ◽  
H. Golestanian ◽  
E. J. Charlson ◽  
T. Stacy
Keyword(s):  
Thin Films ◽  
Activation Energy ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Silicon Substrates ◽  
Boron Doped Diamond ◽  
Diamond Thin Films ◽  
Hot Filament

AbstractAlthough many researchers have studied boron-doped diamond thin films in the past several years, there have been few reports on the effects of doping CVD-grown diamond films with phosphorous. For this work, polycrystalline diamond thin films were grown by hot filament chemical vapor deposition (HFCVD) on p-type silicon substrates. Phosphorous was introduced into the reaction chamber as an in situ dopant during the growth. The quality and orientation of the diamond thin films were monitored by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Current-voltage (I-V) data as a function of temperature for golddiamond film-silicon-aluminum structures were measured. The activation energy of the phosphorous dopants was calculated to be approximately 0.29 eV.

Enhanced UV Photon-response of Tin Nano Cluster Loaded- laser Irradiated ZnO Thin film detector

2011 ◽  
Vol 1288 ◽  
Author(s):  
Rashmi Menon ◽  
K. Sreenivas ◽  
Vinay Gupta
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Magnetron Sputtering ◽  
Surface States ◽  
Response Speed ◽  
Rf Magnetron Sputtering ◽  
Fast Response ◽  
Zno Thin Films ◽  
Zno Thin Film ◽  
Photo Response

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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