ANNEALING EFFECTS ON CONTACT PROPERTIES OF ALUMINUM DOPED ZINC OXIDE THIN FILMS

2002 ◽  
Vol 16 (01n02) ◽  
pp. 294-301
Author(s):  
KE BIN LOW ◽  
HAO GONG ◽  
ENG FONG CHOR
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Structural Changes ◽  
Rf Magnetron Sputtering ◽  
Contact Resistivity ◽  
Glass Substrates ◽  
Specific Contact ◽  
Annealing Effects ◽  
Specific Contact Resistivity ◽  
Diffraction Patterns

Aluminum Zinc Oxide (AZO) thin films are grown on glass substrates by RF Magnetron Sputtering using a single target of zinc oxide (99 wt%) and aluminum oxide (1 wt%) with argon as the plasma. Photolithographic process is then performed on the films in order to obtain a Transmission Line Model structure (TLM) of the metal contact system, namely aluminum and gold. The specific contact resistivity, ρc, of these two metal-semiconductor systems, which will undergo different rapid thermal annealing (RTA) environment, are determined. X-Ray diffraction patterns for these samples are obtained to investigate phase formations or micro-structural changes so as to justify for the differences in specific contact resistivity obtained for these contact systems. The different RTA environment are simulated by purging either nitrogen or argon gas, with a pressure of 40 psi at a temperature of 400°C for 60 s; and annealing in vacuum (10-6 Torr) also at the same temperature and duration. One-dimensional TLM (1D-TLM) measurements are performed on the TLM structures to obtain the specific contact resistivity, ρc. Results show that aluminum contacts on AZO without RTA give the lowest ρc as compared to those in other environment, while gold contacts on AZO annealed in vacuum yield the lowest ρc. Adhesion of aluminum contacts on AZO is good even when subjected to ultrasonic bath test but not true for the case of gold contact, which adheres poorly on AZO films.

Synthesis and Characterization of Nb-Doped TiO2 Thin Films Prepared by RF Magnetron Sputtering

2015 ◽  
Vol 1117 ◽  
pp. 139-142 ◽  
Author(s):  
Marius Dobromir ◽  
Radu Paul Apetrei ◽  
A.V. Rogachev ◽  
Dmitry L. Kovalenko ◽  
Dumitru Luca
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Photoelectron Spectroscopy ◽  
Rf Magnetron Sputtering ◽  
X Ray ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Diffraction Patterns

Amorphous Nb-doped TiO2 thin films were deposited on (100) Si and glass substrates at room temperature by RF magnetron sputtering and a mosaic-type Nb2O5-TiO2 sputtering target. To adjust the amount of the niobium dopant in the film samples, appropriate numbers of Nb2O5 pellets were placed on the circular area of the magnetron target with intensive sputtering. By adjusting the discharge conditions and the number of niobium oxide pellets, films with dopant content varying between 0 and 16.2 at.% were prepared, as demonstrated by X-ray photoelectron spectroscopy data. The X-ray diffraction patterns of the as-deposited samples showed the lack of crystalline ordering in the samples. Surfaces roughness and energy band gap values increase with dopant concentration, as showed by atomic force microscopy and UV-Vis spectroscopy measurements.

scholarly journals Physical Properties of ZnO Thin Films Codoped with Titanium and Hydrogen Prepared by RF Magnetron Sputtering with Different Substrate Temperatures

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Fang-Hsing Wang ◽  
Jen-Chi Chao ◽  
Han-Wen Liu ◽  
Tsung-Kuei Kang
Keyword(s):  
Thin Films ◽  
Magnetron Sputtering ◽  
Film Surface ◽  
Hexagonal Wurtzite Structure ◽  
Rf Magnetron Sputtering ◽  
Force Microscopy ◽  
Glass Substrates ◽  
Transparent Conducting ◽  
Diffraction Patterns ◽  
Substrate Temperatures

Transparent conducting titanium-doped zinc oxide (TZO) thin films were prepared on glass substrates by RF magnetron sputtering using 1.5 wt% TiO2-doped ZnO as the target. Electrical, structural, and optical properties of films were investigated as a function of H2/(Ar + H2) flow ratios (RH) and substrate temperatures (TS). The optimalRHvalue for achieving high conducting TZO:H thin film decreased from 10% to 1% whenTSincreased from RT to 300°C. The lowest resistivity of9.2×10-4 Ω-cm was obtained asTS=100°C andRH=7.5%. X-ray diffraction patterns showed that all of TZO:H films had a hexagonal wurtzite structure with a preferred orientation in the (002) direction. Atomic force microscopy analysis revealed that the film surface roughness increased with increasingRH. The average visible transmittance decreased with increasingRHfor the RT-deposited film, while it had not considerably changed with differentRHfor the 300°C-deposited films. The optical bandgap increased asRHincreased, which is consistent with the Burstein-Moss effect. The figure of merits indicated thatTS=100°C andRH=7.5% were optimal conditions for TZO thin films as transparent conducting electrode applications.

scholarly journals Characteristics of Metal–Semiconductor–Metal Ultraviolet Photodetectors Based on Pure ZnO/Amorphous IGZO Thin-Film Structures

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Kin-Tak Lam ◽  
Sheng-Joue Young ◽  
Yen-Lin Chu ◽  
Chi-Nan Tsai ◽  
Tung-Te Chu ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Rf Magnetron Sputtering ◽  
Indium Gallium Zinc Oxide ◽  
Pure Zinc ◽  
Glass Substrates ◽  
Rejection Ratio ◽  
Light Region ◽  
Metal Semiconductor Metal ◽  
Dark Currents

In this study, metal–semiconductor–metal-structured ultraviolet (UV) photodetectors (PDs) based on pure zinc oxide (ZnO) and amorphous indium gallium zinc oxide (a-IGZO) thin films were fabricated and characterized. The ZnO seed layers were deposited on Corning glass substrates via a radio frequency (RF) magnetron sputtering technique. Results showed that under a 5 V applied bias; the dark currents of the pure ZnO and a-IGZO thin films were 0.112 pA and 2.85 nA, respectively. Meanwhile, the UV-to-visible rejection ratio of the pure ZnO and a-IGZO thin films were 14.33 and 256, respectively. Lastly, the PDs of thea-IGZO thin films had a lower leakage current and higher rejection ratio than that of the pure ZnO thin films from the UV to visible light region.

Piezoresistive Sensitivity and Al Ohmic Contact of Highly Doped Polycrystalline Silicon Nano Thin Films

2011 ◽  
Vol 483 ◽  
pp. 789-793
Author(s):  
Chang Zhi Shi ◽  
Xiao Wei Liu ◽  
Xuan Wu ◽  
Hai Tao Zheng
Keyword(s):  
Thin Films ◽  
Ohmic Contact ◽  
Polycrystalline Silicon ◽  
Depletion Region ◽  
Contact Resistivity ◽  
Gauge Factor ◽  
Piezoresistive Effect ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
Polycrystalline Silicon Films

The piezoresistive and ohmic contact properties of polycrystalline silicon nano thin films were investigated in this paper. The polycrystalline silicon films with different thicknesses and doping concentrations were deposited by LPCVD and doped with boron highly, and then the cantilever beam samples were fabricated by photolithography and wet etching. By measuring the gauge factor and specific contact resistivity, the specific contact resistivity of Al contacts can reach 2.4×10-3Ω·cm2 after the alloying at 450 °C for 20 min; the enhanced piezoresistive effect of highly doped polycrystalline silicon nano thin films was discovered. The conclusions indicated that the enhanced piezoresistive sensitivity of PNTFs is due to the modification of depletion region barrier by ultra high doping and film thickness thinning and the enhancement of tunneling piezoresistive effect. The distinct piezoresistive phenomenon of PNTFs could be utilized for the development and fabrication of miniature piezoresistive sensors.

Dependence of Film Thickness on Properties of Al Doped ZnO Thin Films

2011 ◽  
Vol 194-196 ◽  
pp. 2305-2311
Author(s):  
Ying Ge Yang ◽  
Dong Mei Zeng ◽  
Hai Zhou ◽  
Wen Ran Feng ◽  
Shan Lu ◽  
...  
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Electrical Parameter ◽  
Substrate Surface ◽  
Rf Magnetron Sputtering ◽  
Thickness Effect ◽  
Visible Range ◽  
Glass Substrates ◽  
Doped Zno

In this study high quality of Al doped ZnO (ZAO) thin films were prepared by RF magnetron sputtering on glass substrates at room temperature in order to study the thickness effect upon their structure, electrical and optical properties. XRD results show that the films are polycrystalline and with strongly preferred (002) orientation perpendicular to substrate surface whatever the thickness is. The crystallite size was calculated by Williamson-Hall method, while it increases as the film thickness increased. The lattice stress is mainly caused by the growth process. Hall measurements revealed electrical parameter very dependent upon thickness when the thickness of ZAO film is lower than 700 nm. The resistivity decreased and the carrier concentration and Hall mobility increases as the film thickness increased. When film thickness becomes larger, only a little change in the above properties was observed. All the films have high transmittance above 90% in visible range. Red shift of the absorption edge was observed as thickness increased. The optical energy bandgap decreased from 3.41eV to 3.30 eV with the increase of film thickness.

Metal/P-type GeSn Contacts with Specific Contact Resistivity down to 4.4×10−10 Ω-cm2

2018 ◽  
Author(s):  
Ying Wu ◽  
Wei Wang ◽  
Saeid Masudy-Panah ◽  
Yang Li ◽  
Kaizhen Han ◽  
...  
Keyword(s):  
Contact Resistivity ◽  
Specific Contact ◽  
Specific Contact Resistivity ◽  
P Type
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