Browsing by Author "WU, WF"

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DEPOSITION OF INDIUM TIN OXIDE-FILMS ON ACRYLIC SUBSTRATES BY RADIOFREQUENCY MAGNETRON SPUTTERING
(1994-07-01)
CHIOU, BS
;
HSIEH, ST
;
WU, WF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO) films were deposited onto acrylic substrates by rf magnetron sputtering. Low substrate temperature (<80-degrees-C) and low rf power (<28 W) were maintained during sputtering to prevent acrylic substrate deformation. The influence of sputtering parameters, such as rf power, target-to-substrate distance, and chamber pressure, on the film deposition rate, the electrical properties, as well as the optical properties of the deposited films was investigated. Both the refractive index and the extinction coefficient were derived. The high reflection at wavelengths greater than 3 mum made these sputtered ITO films applicable to infrared mirrors.
EFFECT OF ANNEALING ON ELECTRICAL AND OPTICAL-PROPERTIES OF RF MAGNETRON-SPUTTERED INDIUM TIN OXIDE-FILMS
(1993-08-01)
WU, WF
;
CHIOU, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO, 90wt%In2O3-10wt%SnO2) films of approximately mum thick have been deposited on glass substrates by radio-frequency (RF) magnetron sputtering. The effect of post-deposition heat treatment on the electrical and optical properties of ITO films are investigated. Annealing of ITO-coated substrates at a temperature of 350-550-degrees-C for 2 h in air causes the ITO layers to crystallize and grains to grow. Tin atoms are activated after annealing and behave as effective donors. The electrical resistivity of ITO film decreases by more than two orders of the magnitude after annealing. The infrared reflectance increases as the annealing temperature is raised. An infrared reflectance of approximately 60% (at 5 mum) is obtained for the 550-degrees-C-annealed sample. Several material parameters, such as the effective band gap and the refractive index, have been derived and discussed.
EFFECT OF SPUTTERING POWER ON THE STRUCTURAL AND OPTICAL-PROPERTIES OF RF MAGNETRON-SPUTTERED ITO FILMS
(1994-06-01)
WU, WF
;
CHIOU, BS
;
HSIEH, ST
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The structural and optical properties of RF magnetron sputtered ITO films without in situ substrate heating and post-deposition annealing are investigated. The structure and orientation of ITO films strongly depends on the energy of the sputtered particles arriving at the substrate. As the sputtering power increases from 15 to 100 W, the preferred orientation of the ITC) film changes from (222) to (400). It is observed that the lattice constant of the film increases initially as sputtering power increases from 15 to 50 W and then decreases with further increase of sputtering power. The higher the sputtering power, the smaller the oxygen content of the film. The oxygen deficiency is used to explain the loss of transmittance or blackening of ITO films deposited at high sputtering power. Several material parameters, such as optical constants and energy gap, have been derived and discussed. The figure of merit of the films ranges from 81.3 to 117.6 OMEGA-1.
ELECTRICAL BEHAVIOR OF LOW-POWER RF MAGNETRON-SPUTTERED INDIUM TIN OXIDE-FILMS ON SILICON SUBSTRATE
(1994-04-01)
CHIOU, BS
;
HSIEH, ST
;
WU, WF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO) films were deposited onto p-Si substrates by RF magnetron sputtering. Small sputtering powers (less-than-or-equal-to 28 W) were supplied to a one-inch diameter target, and a low substrate temperature (< 80-degrees-C) was maintained during sputtering. The electrical behavior of the ITO films was explored. The relationship (carrier mobility) a (carrier concentration)-0.64 suggests an impurity scattering mechanism for the transport of charge carriers. A linear current-voltage characteristic and a voltage-independent capacitance indicate that the low-power sputtering process does not damage the ITO/p-Si interface.
FABRICATION AND CHARACTERISTICS OF RF MAGNETRON-SPUTTERED ITO THIN-FILMS
(1994)
WU, WF
;
CHIOU, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
PROPERTIES OF RADIOFREQUENCY MAGNETRON-SPUTTERED ITO FILMS WITHOUT IN-SITU SUBSTRATE HEATING AND POSTDEPOSITION ANNEALING
(1994-07-15)
WU, WF
;
CHIOU, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO) films have been prepared by radio-frequency (r.f.) magnetron sputtering an oxide target (90 wt.% In2O3-10 wt.% SnO2) onto glass substrates without in-situ substrate heating. The effect of sputtering conditions on the deposition rate and the optical and electrical properties of ITO films are investigated. The as-deposited films have an electrical resistivity of approximately 4 x 10(-4) OMEGA cm, visible transmittance of about 85%, and infrared reflectance of above 80% at 5 mum. A virtual source of the sputtered particles is formed in the gap between the target and substrate and its position is related to the energy of the sputtered particles. The position of the virtual source is used to explain the correlation between the deposition rate and target-to-substrate distance. The O/In atomic ratio is found to decrease with increasing sputtering power, resulting in an increase in the carrier concentration of the film and a decrease in the Hall mobility. Blackening of ITO films deposited at high sputtering power is observed and discussed.
SIZE EFFECT ON THE ELECTRICAL-CONDUCTION AND NOISE OF RUO2-BASED THICK-FILM RESISTORS
(1992-12-01)
CHIOU, BS
;
SHEU, JY
;
WU, WF
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Temperature dependence of sheet resistance for a generic RuO2-based resistor with a composition of 20 wt.% RuO2-80 wt.% glass (63 wt.% PbO-25 wt.% B2O3-12 wt.% SiO2) is evaluated. A combined tunnel/parallel conduction model is employed to describe the resistance behavior with respect to the temperature variation. The geometry of the resistive film, such as the aspect ratio and thickness, cast a significant effect on the electrical characteristic of the thick film assembly. It is observed that shorter resistive films exhibit smaller resistivity as compared to that of the longer film. Thinner resistive films have smaller resistivity as compared to the thicker ones. In addition, 1/f noise is the dominating contribution in the thick film resistor. The presence of 1/f noise can be qualitatively explained with the aid of the tunneling mechanism.