The bit error rates of DS/SSMA DPSK system with diversity and FEC channel coding in Rayleigh fading and log-normal shadowing channel are evaluated. Microscopic postdetection diversity and macroscopic selection diversiity are used to mitigate the effects of Rayleigh fading and log-normal shadowing, respectively. The numerical results show that the composite use of diversity and channel coding is very efficient for improving system performance compared to their respective uses.

We have proposed a soft-decision decoding method for block codes. With careful examinations of the first hard-decision decoded results, The candidate codewords are efficiently searched for. Thus, we can reduce the decoding complexity (the number of hard-decision decodings) and lower the block error probability. Computer simulation results are presented for the (23,12) Golay code. They show that the decoding complexity is considerably reduced and the block error probability is close to that of the maximum likelihood decoder.

By using the point matching method, the coplanar waveguide shielded by the rectangular waveguide has been analyzed. The particular potential solution of C.P.W has been obtained from the boundary condition by using the point matching method. The line capacitance has been obtained from the total charge of the center conductor per length. The effective dielectric constant and the line impedance have been obtained from the line capacitance of C.P.W.

We have analyzed shielding characteristics of the spherical multilayered dielectric, with the assumption that the inner part of the model is filled with the perfect conductor whose radius is varied from 0.2.lambda. to 1.0.lambda. and the outer part of the conducting sphere is covered by a lossy multilayered dielectric. Variation of shielding effects have been examined as the function of parameter of the dielectric layer and the radius of the conducting sphere.

A novel insulated gate bipolar transister (IGBT), called insulated trench cathode IGBT (ISTC-IGBT), is proposed. ISTC-IGBT has a trenched well with the shallow P$^{+}$ juction in the conventional IGBT structure. The proposed structure has the capability of effectively suppressing the parasitic thyristor latchup. The holding current of ISTC-IGBT is about 2.2 times greater than that of the conventional IGBT. Detailed analysis of the latchup characteristics of ISTC-IGBT is performed by using the two-dimensional device simulator, PISCES-II B.

Based on the close correlation between the optoelectronic and electrical characteristics of laser diodes, this paper is to present an exact model for electrical characteristics of laser diodes with bulk active layers so that the optoelectronic characteristics may be estimated from the electrical Characteristics. Among the considered models, the most exact model is shown to be one which uses the Fermi-Dirac integral and the bimolecular recombination and takes into account the energy-gap shrinkage with the injected carrier density.

16M DRAM 용 Al/Si contact 의 열적안정성을 개선하기 위하여 "stuffed" TiN/Ti diffusion barrier를 사용하였다. Diffusion barrier 로서의 특성을 개선하기 위한 Al 증착전 TiN/Ti barrier metal의 열처리 과정중 barrier metal의 두께, 열처리온도, 분위기 등을 변화시켰다. 질소분위기하에서 450도에서 TiN(900A)/Ti(300A) 박막을 열처리 하여 "stuffed" barrier metal을 형성 시켰을 경우 Al 원자의 TiN층으로의 확산의 600도에서 후속열처리한 경우 일어났으나, 700도까지도 Al-spike를 관찰할 수 없었다. 그러나 "stuffed" barrier metal을 550도에서 형성한 경우에는 600도의 후속열처리온도에서 Al이 Si 기판으로 침투했음을 관찰하였다. 박막의 두께를 얇게한 경우, 600도의 후속 열처리에서 Al-spike가 형성되었음을 확인하였다.

Experiments of RIE of tungsten films using SF$_{6}$ plasma were conducted to investigate the effect of process parameters on etch rate, uniformity, anisotropy, and selectivity. As power increased, the etch rate increased. Maximum etch rate was obtained at 200mtorr As interelectrode spacing increased the etch rate increased for P < 200mtorr while it decreased for P> 200mtorr. Etch rate was maximum at 20 sccm gas flow rate. As substrate temperature increased, the etch rate increased and activation energy was 0.046 eV. In addition, maximum etch rate was acquired at 20% $O_{2}$ addition. The etch rate slightly increased when Ar was added up to 20% while it continuously decreased when N$_{2}$ was added. Uniformity got improved as pressure decreased and was less than 4% for P <100mtorr. Mass spectrometer was utilized to analyze gas composition and S and F peaks were observed from XPS analysis with increasing power. The anisotropy was better for smaller power and spacing, and lower pressure and temperature. It improved when CH$_{4}$ was added and anisotropic etch profile was obtained when about 10% $O_{2}$ was added. The selectjvity was better for smaller power larger pressure and spacing, and lower temperature. Especially. low temperature processing was proposed as a novel method to improve the anisotropy and selectivity.

In this paper, New type of Static Edge Triggered D Flip-Flop Circuits which are effective for the sequencial selecting and addressing of Matrix type Electrodes being applied to Flat Display Devices is proposed by the Design Technique using the Transmission Characteristics of Feedback Transistors and Charge Back Up Function. These Circuits composed of 2-4 less transistors in number than Conventional Static D Flip Flop's have some advantages that the Maximum Transition Time of Clock Signals allowed is increased by 100-450 times more than that of the Conventional circuit at 100KHz Clock Frequence and Circuit Safety is much increased by making the wider ranges, 1-4V, of Clock Levelas a Non-operating periods than 3-3.2V ranges in case of the Conventional Circuit at 10MHz clock frequence. By these advantages, These circuits can be very effectively used in case that clock signal has long transition time, especially on the low frequency operation.

This paper describes fabrication of relative type capacitive pressure sensor to be in great demand for many fields. The fabricated sensor consists of two parts` a sensing diaphragm and a pyrox glass cover. The sensor size is 4.5${\times}3.4mm$^{2})$ and 400$\mu$m thick. To improve the nonlinearity, this sensor is designed a rectangular silicon diaphragm with a center boss structure, and in order to improve the temperature characteristics of the sensor in a packaging process, the sensing element is mounted on the pyrex glass support. Some suggestions toward the design and fabrication of improved sensors have been presented. The zero pressure capacitance, Co of sensor is 26.57pF, and the change of capacitance, ${\Delta}$C is 1.55pF from 0Kgf/Cm$^{2}$ to 1Kgf/Cm$^{2}$ at room temperature. The nonlinearity of the sensor output with center boss diaphragm is 1.29%F.S., and thermal zero shift and thermal sensitivity shift is less than 1.43%F.S./$^{\circ}C$and 0.14% F.S./$^{\circ}C$, respectively.