• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1085-1087
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• 1995

A large leakage current may be one of the critical issues for poly-silicon thin film transistors(poly-Si TFTs) for LCD applications. In order to reduce the leakage current of poly-Si TFTs, several offset gated structures have been reported. However, those devices, where the offset length in the source region is not same as that in the drain region, exhibit the asymmetric electrical performances such as the threshold voltage shift and the variation of the subthreshold slope. The different offset length is caused by the additional mask step for the conventional offset structures. Also the self-aligned implantation may not be applicable due to the mis-alignment problem. In this paper, we propose a new fabrication method for poly-Si TFTs with a self-aligned offset gated structure by employing a photo resistor reflow process. Compared with the conventional poly-Si TFTs, the device is consist of two gate electrodes, of which one is the entitled main gate where the gate bias is employed and the other is the entitled subgate which is separate from both sides of the main gate. The poly-Si channel layer below the offset oxide is protected from the injected ion impurities for the source/drain implantation and acts as an offset region of the proposed device. The key feature of our new device is the offset lesion due to the offset oxide. Our experimental results show that the offset region, due to the photo resistor reflow process, has been successfully obtained in order to fabricate the offset gated poly-Si TFTs. The advantages of the proposed device are that the offset length in the source region is the same as that in the drain region because of the self-aligned implantation and the proposed device does not require any additional mask process step.

• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.546-551
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• 2009

In this paper, we describe a self-aligned fabrication method for a nano-patterned bottom electrode using flood exposure from the backside. Misalignments between layers could cause the final devices to fail after the fabrication of the nano-scale bottom electrodes. A self-alignment was exploited to embed the bottom electrode inside the glass substrate. Aluminum patterns act as a dry etching mask to fabricate glass trenches as well as a self-aligned photomask during the flood exposure from the backside. The patterned photoresist (PR) has a negative sidewall slope using the flood exposure. The sidewall slopes of the glass trench and the patterned PR were $54.00^{\circ}$ and $63.47^{\circ}$, respectively. The negative sidewall enables an embedment of a gold layer inside $0.7{\mu}m$ wide glass trenches. Gold residues on the trench edges were removed by the additional flood exposure with wet etching. The sidewall slopes of the patterned PR are related to the slopes of the glass trenches. Nano-scale bottom electrodes inside the glass trenches will be used in beam resonators operating at high resonant frequencies.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
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• pp.57-60
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• 2005

We have recently developed new organic TFT technologies such as self-aligned self-assembly (SALSA) process and a high-resolution color active-matrix LCD panel. A new method to realize high-resolution printable organic TFT array to drive active-matrix flat-panel display will be discussed.

• 대한전기학회논문지
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• 제45권2호
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• pp.249-255
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• 1996

A self-aligned latch-up suppressed IGBT has been proposed and the process method and the device characteristics of the IGBT have been verified by numerical simulation. As the source is laterally diffused through the sidewall of the trench in the middle of the body, the size of the source is small and the doping concentration of the source is lower than that of the p++ body and the emitter efficiency of the parasitic npn transistor is low so that latch-up may be suppressed. No additional mask steps for p++ region, source, and source contact are required so that small sized body can be obtained Latch-u current density higher than 10000 A/cm$^{2}$ have been achieved by adjusting the process conditions.

• 전자공학회논문지A
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• 제32A권1호
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• pp.146-151
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• 1995

We have studied the fabrication self aligned atmospheric pressure(AP) CVD a-Si thin film transistor with source-drain ohmic contact by using ion shower doping method. The conductivity is 6*10$^{-2}$S/cm when the acceleration voltage, doping time and doping temperature are 6kV, 90s and 350.deg. C, respectively. We obtained the field effect mobility of 1.3cm$^{2}$/Vs and the threshold voltage of 7V.

• Transactions on Electrical and Electronic Materials
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• 제3권3호
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• pp.8-13
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• 2002

Controlled precipitation of quasi-binary semiconductor system is newly proposed as an effective and reliable technique for the formation of well-defined and crystallographically aligned semiconductor nanostructures. Using HgTe-PbTe quasi-binary semiconductor system, self-aligned HgTe nanocrystallites distributed three dimensionally within PbTe matrix were successfully formed by the simple three step heat treatment process routinely found in age hardening process of metallic alloys. Examination of the resulting nano precipitates using conventional transmission electron microscopy (CTEM) and high resolution TEM (HRTEM) reveals that the coherent HgTe precipitates form as thin discs along the (100) habit planes making a crystallographic relation of {100}$\_$HgTe///{100}$\_$PbTe/ and [100]$\_$HgTe///[100]$\_$PbTe/. It is also found that the precipitate undergoes a gradual thickening and a faceting under isothermal aging up to 500 hours without any noticeable coarsening. These results, combined with the extreme dimension of the precipitates (4-5 nm in length and sub-nanometer in thickness) and the simplicity of the formation process, leads to the conclusion that controlled precipitation is an effective method for preparing desirable quantum-dot nanostructures.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.1539-1543
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• 2006

We have developed self-aligned imprint lithography (SAIL) technology, an innovative method for roll-to-roll (R2R) fabrication of electronic devices on flexible plastic substrates. In this paper, we present the first R2R-produced ${\alpha}$-Si TFTs built on a polyimide substrate using the SAIL process, and prove the feasibility of this technology to enable R2R fabrication of flexible display active matrix (AM) backplanes with high precision and throughput.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제16회 학술발표회 논문개요집
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• pp.29-29
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• 1998

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2003년도 춘계학술대회논문집
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• pp.434-438
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• 2003

The shearing process for the sheet metal is normally used in the precision elements such as semi-conductor components. In these precision elements, the burr formation brings a bad effect on the system assembly and demands the additional de-burring process. In this paper, we have developed the desktop-type precision punching system to investigate the burr formation mechanism and present kinematically Punch-die auto aligning methodology, for the purpose of burr unifomizing and minimizing, between the rectangular shaped punch and die. By using the scanning electron microscope, the aligned punching results are compared with the miss-aligned ones. Also, we measured the relative burr heights using the self-designed laser measuring device for insitu self aligning. Since it is hard to get the perfect, so called, burr-free edges during the shearing process, we introduced the ultrasonic do-burring machine. The de-burring operation was carried out by a novel do-burring method, the reversal flow resistance method, under different machining loads and abrasive types. The final do-burring results show the validity of our punching do-burring system pursuing the burr-free punched elements.

• 한국세라믹학회지
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• 제37권5호
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• pp.444-452
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• 2000

Dense composites of titanium matrix and Al2O3 matrix with reinforcements of carbon or titanium carbide fibers were successfully fabricated by high-pressure self-combustion sintering method or combustion reacton under 30 MPa of uniaxial pressure with an aid of external heating in vaccum. It was found that the fibers were uniformly distributed in the matrix, and aligned in a phase perpendicular to the pressure axis. As a moel ratio of Ti/C or reaction time increased, the density of Ti-matrix composite increased Micro pores around fibers could be removed by using clean carbon fibers without sizing agent on their surface. The evolution of carbide fibers from carbon fibers was observed. The composition of the various phases around fibers were analyzed.