• JSTS:Journal of Semiconductor Technology and Science
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• v.2 no.4
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• pp.273-279
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• 2002

This paper presents a fabrication technology for the integration of single crystal Si microstructures with on-chip circuitry. It is a dissolved wafer technique that combines an electro-chemical etch-stop for the protection of circuitry with an impurity-based etch-stop for the microstructures, both of which are defined in an n-epi layer on a p-type Si wafer. A CMOS op. amp. has been integrated with $p^{++}$ Si accelerometers using this process. It has a gain of 68 dB and an output swing within 0.2 V of its power supplies, unaffected by the wafer dissolution. The accelerometers have $3{\;}\mu\textrm{m}$ thick suspension beams and $15{\;}\mu\textrm{m}$ thick proof masses. The structural and electrical integrity of the fabricated devices demonstrates the success of the fabrication process. A variety of lead transfer methods are shown, and process details are discussed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.1
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• pp.51-54
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• 2009

Transparent Cuprous oxide film was deposited by rapid thermal oxidation (RTO) of Cu at $500^{\circ}C$/45s condition on textured single-crystal n-Si substrate to form $Cu_2O$/n-Si heterojunction photodiode. The Hall effect measurements for the $Cu_2O$ films showed a p-type conductivity. The photovoltaic and electrical properties of the junction at room temperature were investigated without any post-deposition annealing. I-V characteristics revealed that the junction has good rectifying properties. The C-V data showed abrupt junction and a built-in potential of 1 V. The photodiode showed good stability and high responsivity in the visible at three regions; 525 nm, 625-700 nm, and 750nm denoted as regions A, B, and C, respectively.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.346-349
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• 2009

We investigated the doping effects of $ReO_3$ in different p-type organic semiconductors on the formation of charge transfer complexes and the electrical conductivity by comparing the absorption in ultraviolet-visible-nearinfrared (UV-Vis-NIR) and the current density-voltage characteristics of the hole only devices, respectively. The large energy difference between the HOMO level of host and Fermi energy level of dopant (${\Delta}E$=$E_{HOHO,host}$ - $E_{F,dopant}$) gives higher concentration of CT complexes and enhanced conductivity.

• Journal of IKEEE
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• v.14 no.4
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• pp.257-262
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• 2010

We design a CMOS front-end with wide variable gain and low power consumption for 5.25 GHz band. To obtain wide variable gain range, a p-type metal-oxide-semiconductor field-effect transistor (PMOS FET) in the low noise amplifier (LNA) section is connected in parallel. For a mixer, single balanced and folded structure is employed for low power consumption. Using this structure, the bias currents of the transconductance and switching stages in the mixer can be separated without using current bleeding path. The proposed front-end has a maximum gain of 33.2 dB with a variable gain range of 17 dB. The noise figure and third-order input intercept point (IIP3) are 4.8 dB and -8.5 dBm, respectively. For this operation, the proposed front-end consumes 7.1 mW at high gain mode, and 2.6 mW at low gain mode. The simulation results are performed using Cadence RF spectre with the Taiwan Semiconductor Manufacturing Company (TSMC) $0.18\;{\mu}m$ CMOS technology.)

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.3
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• pp.268-274
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• 1999

The problem of power factor and hmmonics are occurred in convelter system which used to SCRs and diodes as p power semiconductor devices. IGBT power device with selh:ommutation type was solved that problem. maintain the l input line current with sinusoidal wave CUlTent of input power source voltage. It was estimated that improvement of t transient state characteristics with feedfolward compensator added in the diode rectifier with single phase voltage type i inverter was used to simulation load. As a results it was verified that the transient state characteristics with voltage t type PWM convelter control was improved.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.387.1-387.1
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• 2016

Transparent materials are necessary for most photoelectric devices, which allow the light generation from electric energy or vice versa. Metal oxides are usual materials for transparent conductors to have high optical transmittance with good electrical properties. Functional designs may apply in various applications, including solar cells, photodetectors, and transparent heaters. Nanoscale structures are effective to drive the incident light into light-absorbing semiconductor layer to improve solar cell performances. Recently, the new metal oxide materials have inaugurated functional device applications. Nickel oxide (NiO) is the strong p-type metal oxide and has been applied for all transparent metal oxide photodetector by combining with n-type ZnO. The abrupt p-NiO/n-ZnO heterojunction device has a high transmittance of 90% for visible light but absorbs almost entire UV wavelength light to show the record fastest photoresponse time of 24 ms. For other applications, NiO has been applied for solar cells and transparent heaters to induce the enhanced performances due to its optical and electrical benefits. We discuss the high possibility of metal oxides for current and future transparent electronic applications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.3
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• pp.220-226
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• 2002

Amorphous $Sb_{2-x}Bi_xTe_3$ (x = 0.0, 0.5 and 1.0) thin films were prepared by vacuum evaporation. The resistivity of 7he films decreases from 1.4{\times}10^{-2}$ to $8.84{\times}10^{-5}\Omega cm$ and the type of conductivity changes from p to n with the increase of the x value of the films. D.C. conduction studies on these films ate performed at various electric fields in the temperature range of 303-403 K. At low electric fields, two types of conduction mechanisms, i.e. the variable range hopping and the phonon assisted hopping are found to be responsible for the conduction, depending upon the temperature. The activation energy decreases from 0.082 to 0.076 eV in the temperature range of 303-363 K and from 0.47-0.456 eV in the second range of 363-403 K, indicating the shift of the Fermi level towards the conduction band edge and hence the change of the conduction from P to n type with the increase of the Bi concentration. Poole-Frankel emission dominates at high fields. The shape of the potential well of the localized centre is deduced and the mean free path of the charge carriers is also calculated.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.272-272
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• 2014

SnO thin films, 100 nm in thickness, were deposited on glass substrates by RF magnetron sputtering. A stack structure of $SnO_2/SnO$, where few nanometers of $SnO_2$ were determined on the SnO thin film by X-ray photoelectron spectroscopy. In addition, XPS depth profile analysis of the pristine and heat treated thin films were introduced. The electrical behavior of the as-sputtered films during the annealing was recorded to investigate the working conditions for the SnO sensor. Subsequently, The NH3 sensing properties of the SnO sensor at operating temperature of $50-200^{\circ}C$ were examined, in which the p-type semiconducting sensing properties of the thin film were noted. The sensor shows good sensitivity and repeatability to $NH_3$ vapor. The sensor properties toward several gases like $H_2S$, $CH_4$ and $C_3H_8$ were also introduced. Finally, a sensing mechanism was proposed and discussed.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.843-847
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• 2014

In Super Junction (SJ) MOSFETs, charge balance is the most important issue of the SJ fabrication process. In order to achieve the best electrical characteristics, such as breakdown voltage and on-resistance, the N-type and P-type drift regions must be fully depleted when the drain bias approaches the breakdown voltage, which is known as the charge balance condition. In conventional charge balance analysis, based on multi-epi process SJ MOSFETs, analytical model has only N, P pillar width and doping concentration parameter. But applying a conventional charge balance principle to trench filling process, easier than Multi-epi process, is impossible due to the missing of the trench angle parameter. To achieve much more superior characteristics of on-resistance in trench filling SJ MOFET, the appropriate trench angle is necessary. So in this paper, modulated charge balance analysis is proposed, in which a trench angle parameter is added. The proposed method is validated using the TCAD simulation tool.

• Korean Chemical Engineering Research
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• v.49 no.3
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• pp.357-360
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• 2011

N-doped ZnO nanofilms were prepared by plasma enhanced atomic layer deposition method. $Zn(C_{2}H_{5})_{2}$, $O_{2}$ and $N_{2}$ were used as Zn, O and N sources, respectively, for N-doped ZnO films under variation of radio frequency (rf) power from 50-300W. Structural, optical and electrical properties of as-grown ZnO films were investigated with Xray diffraction(XRD), photoluminescence(PL) and Hall-effect measurements, respectively. Nitrogen content and p-type conductivity in ZnO nanofilms increased with the rf power.