• Journal of the Korean Institute of Telematics and Electronics C
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• v.36C no.5
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• pp.27-37
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• 1999

A CMOS ReadOut Integrated Circuit (ROlC) for InfraRed Focal Plane Array (IRFPA) detector is presented, which is a key component in uncooled thermal imaging systems. The ROIC reads out signals from $64\times64$ Barium Strontium Titanate (BST) infrared detector array, then outputs pixel signals sequentially after amplifying and noise filtering. Various design requirements and constraints have been considered including impedance matching, low noise, low power dissipation and small detector pitch. For impedance matching between detector and pre~amplifier, a new circuit based on MOS diode structure is devised, which can be easily implemented using standard CMOS process. Also, tunable low pass filter with single~pole is used to suppress high frequency noise. In additions, a clamping circuit is adopted to enhance the signal~to-noise ratio of the readout output signals. The $64\times64$ IRFPA ROIC is designed using $0.65-\mu\textrm{m}$ 2P3M (double poly, tripple metal) N~Well CMOS process. The core part of the chip contains 62,000 devices including transistors, capacitors and resistors on an area of about $6.3-mm\times6.7-mm$.

• Journal of the Microelectronics and Packaging Society
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• v.26 no.4
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• pp.127-132
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• 2019

In this study, barium strontium titanate (BSTO) with high dielectric perovskite structure was synthesized by liquid-solid solution synthesis and the surface was modified using trimethylsilyl chloride (TMCS) as a silylation agent. Silylation surface modification is a method of reacting -OH ligand on the surface of BSTO nanoparticles with Cl in TMCS to generate HCl and replacing the ligand on the surface of nanoparticles with -Si, -CH₃. Silylation was optimized by varying the concentration of TMCS, and the structure of the silicon network was confirmed by Fourier-transform infrared spectroscopy. In addition, the crystallinity of BSTO nanoparticles was confirmed by X-ray diffractometer and the size of the nanoparticles was calculated using Scherrer equation. The field emission scanning electron microscopic image observed the change of the surface-modified BSTO particle size, and the contact angle measurement confirmed the hydrophobic property of the contact angle of 120.9° in the optimized nanoparticles. Finally, the surface-modified BSTO dispersion experiment in de-ionized water confirmed the hydrophobic degree of the nanoparticles.

• Transactions on Electrical and Electronic Materials
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• v.10 no.2
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• pp.49-52
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• 2009

Barium strontium calcium titanate powders were prepared with the sol-gel method. Ferroelectric $(Ba_{0.54}Sr_{0.36}Ca_{0.1})TiO_3$(BSCT) thick films were fabricated by the screen-printing method on alumina substrate. Then we investigated the structural and dielectric properties of the BSCT thick films at different sintering temperatures. The thermal analysis showed that the BSCT polycrystalline perovskite phase formed at around $660^{\circ}C$. The X-ray diffraction analysis showed a cubic perovskite structure with no second phase present in all of the BSCT thick films. The average grain size and the thickness of the specimens sintered at $1450^{\circ}C$ were about $1.6{\mu}m$ and $45{\mu}m$, respectively. The relative dielectric constant increased and the dielectric loss decreased as the sintering temperature was increased; for BSCT thick films sintered at $1450^{\circ}C$ the values of the dielectric constant and the dielectric loss were 5641 and 0.4%, respectively, at 1 kHz.

• Journal of the Korean Ceramic Society
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• v.29 no.9
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• pp.689-694
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• 1992

Strontium Titanate single crystal is grown by Verneuil method. Feed materials were prepared by coprecipitation method which started with Sr(NO3)2 and TiCl4. SrTiO3 can not be grown from feed materials having the stoichiometric components due to volatilization of SrO, when the powder added more 3 wt% SrO used, the crystal can be grown. Growth conditions that the pressure of oxygen and hydrogen gas was 5 psi, the flow rate of oxygen and hydrogen was 7.3 and 30ι/min respectively, the growth rate was 20 mm/hr were optimum. The grown single crystal has the diameter of 10~15 mm and its length is 30~40 mm. The grown crystal was deep brown color and somewhat transparent. The color of grown crystal was lightened after annealing.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.286-288
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• 2003

In this paper, in order to obtain a large differential phase shift with a little change in applied voltage, a ferroelectric reflective load circuit has been designed on top of barium strontium titanate $(Ba,Sr)TiO_3$ [BST] thin film. The design of the ferroelectric reflection-type phase shifter is based on a reflection theory of terminating circuit, which has a reflection-type analogue phase shifter with two ports terminated in symmetric phase-controllable reflective networks. To achieve large amounts of phase shift in low bias-voltage range, the effects of change of capacitance and transmission line connected with two coupled ports of a 3-dB $90^{\circ}$ branch-line hybrid coupler have been investigated. A large phase shift with a small capacitance change in the parallel terminating circuit has been demonstrated in the paper.

• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.679-684
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• 1998

Dielectricand pyroelectric properties of {{{{ { { {Ba }_{0.67 }Sr }_{0.33 } }`TiO_{3 } ^{ } }} (BST) thin plates and films were investigated. For BST thin plates maximum dielectric constant and pyrolelectric coefficient were observed at around 24$^{\circ}C$ and pyroelectric characteristics were improved as applied bias field was increased. When the electric field of 4kV/cm was applied to the thin plates sintered at 140$0^{\circ}C$ the pyroelectric coefficients over 4$\times$10-7C/{{{{ { cm}^{2 }K }} were obtained in the range of 0-4$0^{\circ}C$ BST thin films deposited using rf magnetron sputtering showed [001] preferred orientation at substrate temperatures above 50$0^{\circ}C$ On the contrary to the thin plates the dielectric constants of the thin films gradually increased above 15$^{\circ}C$ and decreased as applied bias field in-creased. The pyroelectric coefficients of thin films were lower than 1/10 those of thin plates.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.11
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• pp.855-858
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• 2011

In this paper, in order to suppress unwanted current paths originating from adjacent cells in a passive crossbar array based on resistive random access memory (RRAM) without extrinsic switching devices, 1-diode type RRAM which consists of a 0.2% chromium-doped strontium titanate (Cr-$SrTiO_3$) film deposited on a silicon substrate, was proposed for high packing density, and intrinsic rectifying characteristics from the current versus voltage characteristics were successfully demonstrated.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.167-167
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• 2008

The barium strontium calcium titanate powders were prepared by sol-gel method. Ferroelectric $(Ba_{0.54}Sr_{0.36}Ca_{0.1})TiO_3$(BSCT) thick films were fabricated by the screen-printing method on alumina substrate. And we investigated the structural and dielectric properties of BSCT thick films with the variation of sintering temperature. As a result of thermal analysis, BSCT polycrystalline perovskite phase was formed at around $660^{\circ}C$. The results of X-ray diffraction analysis were showed a cubic perovskite structure without presence of the second phase in all BSCT thick films. The average grain size and the thickness of the specimen sintered at $1450^{\circ}C$ were about 1.6 mm and 45 mm, respectively. The relative dielectric constant increased and the dielectric loss decreased with increasing the sintering temperature, the values of the BSCT thick films sintered at $1450^{\circ}C$ were 5641 and 0.4% at 1kHz, respectively.

• Journal of the Korean Ceramic Society
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• v.51 no.3
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• pp.224-230
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• 2014

Nano-sized gadolinium-doped ceria (GDC)/nickel particle-dispersed $La_ySr_{1-y}Ti_{1-x}Fe_xO_3$ (LSFTO)-based composite solid oxide fuel cell anodes were fabricated by an infiltration method and the effects of the GDC/Ni nanoparticles on the anode polarization resistance and cell performance were investigated in terms of the infiltration time and nickel content. The anodic polarization resistance of the LSFTO anode was significantly enhanced by GDC and/or Ni infiltration and it decreased with increasing infiltration time and Ni content, respectively. It is believed that the observed phenomena are associated with enhancement of the ionic conductivity and catalytic activity in the nanocomposite anodes by the addition of GDC and Ni. Power densities of cells with the LSFTO and LSFTO-GDC/Ni nanocomposite anodes were 150 and $300mW/cm^2$ at $800^{\circ}C$, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.402-405
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• 2001

$(Ba_{0.6-x}Sr_{0.4}Ca_{x})TiO_{3}$ (x=0.10, 0.15, 0.20) ceramics were fabricated by the mixed-oxide method and their stuctural and dielectric properties were investigated with variation of composition ratio and an amount of $Al_{2}O_{3}$ (0.5, 1.0, 1.5. 2.0, 3.0 wt%) doping content. As a result of the X-ray diffraction BSCT specimens showed dense and homogeneous structure without presence of the second phase. The sintered density was decreased with increase an $Al_{2}O_{3}$ doping content. The Curie temperature and relative dielectric constant at room temperature were decreased with increasing an amount of $Al_{2}O_{3}$ doping content. The dielectric loss is minimum for BSCT doped with 1.5wt% $Al_{2}O_{3}$ content. The tunability was decreased with increasing an Ca content and is about 4.2% for BSCT(50/40/10) doped with 2.0wt% $Al_{2}O_{3}$ content.