• Journal of the Korean Ceramic Society
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• v.41 no.8
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• pp.578-581
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• 2004

In this study, we proposed the novel method that can crystallize the amorphous silicon by adjacent Pd-MILC enhanced Ni-MILC. With this method, the MILC rate was about 15 ${\mu}$m/h at 550$^{\circ}C$ which is four times faster than conventional MILC rate. The crystallization rate increased rapidly with the spacing between Ni and Pd decreased. And it was independent on Ni and Pd layer thickness and amorphous silicon active width. However, when Pd was capped by a Ni layer, there's no enhancement on Ni-MILC. This phenomenon implies that the enhancement of Ni-MILC rate comes from not Pd material itself but Pd-MILC induced tensile stress. We can explain these phenomena with a novel MILC mechanism.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.172-172
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• 2003

It has been known that Pd-MILC shows much faster and lower temperature crystallization than Ni-MILC but it can not be put into practice due to the quality issue of thus fabricated poly crystals. In this study, addition of Pd into Ni-MILC has been attempted in order to take advantages of the Pd-MILC without sacrificing of the Ni-MILC TFTs. It turns out that when 5% of Pd has been added to Ni for MILC, MILC growth rate increases two - three times faster than pure Ni-MILC. The MILC growth rate shows monotonic increase with increase the amount of Pd in Ni up to 50%. Even when small amount of Pd was added to Ni like 5%, crystallization phenomenon already follows the way of Pd-MILC. The Poly-W thus fabricated shows lower leakage current than pure Ni-MILC TFT without losing any amount of on-current This fact is very important in low temperature poly-TFTs because MILC-TFTs, especially suffer from the relatively high leakage current

• Korean Journal of Materials Research
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• v.14 no.7
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• pp.500-504
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• 2004

It is well-known that adjacent Pd-MILC enhanced the rate of Ni-MILC. And the phenomena can be explained by tensile stress propagation between amorphous silicon and Pd silicide which is catalyst of crystallization. In this study, we modified tensile stress by changing geometry of amorphous silicon to prove that there is a direct relation between tensile stress and Ni-MILC rate enhancement. When the tensile stress concentrated, the Ni-MILC rate was enhanced more(14.5 ${\mu}m/hr$) by Pd-MILC while the conventional Pd-MILC enhanced Ni-MILC rate was 11 ${\mu}m/hr$. As the result we can be sure that the tensile stress causes the enhancement of Ni-MILC rate.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.307-309
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• 2005

We investigated light absorption layer effect on metal-induced lateral crystallization (MILC) growth rate and MILC thin films transistors (TFTs). As annealing method, we used scanning-rapid thermal annealing (RTA). MILC growth rate which was crystallized by light absorption layer and using scanning-RTA was 3 times than normal MILC which was without light absorption layer growth rate. Also we compared MILC TFTs characteristics which were combined to light absorption layer with conventional MILC TFTs. After scanning-RTA process, MILC-TFTs which were with light absorption layer were superior to conventional MILC-TFTs. With this new MILC-TFTs structure, we could reduced crystallization time and obtain good electrical properties.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.201-201
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• 2003

It has been well known that Ni-MILC TFTs are acceptable for operation of LCD devices but still decrease of annealing temperature is desirable for the future devices like LCD on the plastic substrate. In this work, Cu was added to Ni-MILC in an attempt to lower the annealing temperature and enhance the MILC rate. It has been found that even small amount of Cu addition enhances the MlLC rate considerably. Also well One MILC can be distinguished from island type, which cannot be observed in pure Ni-MILC. Poly TFTs were fabricated with Cu/Ni-MILC and the effects of copper addition on the electrical properties were carefully investigated.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.05a
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• pp.173-179
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• 2005

본 연구에서는 Nickel-Metal Induced Lateral crystallization(Ni-MILC)에 depart에 따른 영향을 관찰함에 있어 Nickel에 Palladium Metal을 인접시켜(Pd assisted Ni-MILC) 그 결정화 속도를 향상시키는 방법을 제안하였다. a-Si에 Phosphorous가 doping 되어 있는 경우 Ni-MILC의 성장은 intrinsic에 비해 2.5배 감소되는 반면, Boron을 doping한 경우 Ni-MILC의 성장은 intrinsic의 경우보다 5배 이상의 성장을 보이게 되는데, well type의 Pd을 인접시킨 경우 Pd에 의해 유도된 tensile stress가 각 doping에 따른 성장 속도를 더욱 증대시키는 것을 확인할 수 있었으며, 이와 같은 현상을 MILC mechanism으로 설명하였다. 이는 Ni-MILC를 이용하여 다결정 실리콘 TFT 제작 시 결정화 속도로 인하여 문제가 되었던 N-type에서의 적용이 가능함과 동시에 contact MILC 등의 방법에도 이용가능성을 의미한다.

• Korean Journal of Materials Research
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• v.14 no.7
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• pp.477-481
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• 2004

High quality polycrystalline silicon is very critical part of the high quality thin film transistor(TFT) for display devices. Metal induced lateral crystallization(MILC) is one of the most successful technologies to crystallize the amorphous silicon at low temperature(below $550^{\circ}C$) and uses conventional and large glass substrate. In this study, we observed that the MILC behavior changed with abrupt variation of the amorphous silicon active pattern width. We explained these phenomena with the novel MILC mechanism model. The 10 nm thick Ni layers were deposited on the glass substrate having various amorphous silicon patterns. Then, we annealed the sample at $550^{\circ}C$ with rapid thermal annealing(RTA) apparatus and measured the crystallized length by optical microscope. When MILC progress from narrow-width-area(the width was $w_2$) to wide-width-area(the width was $w_1$), the MILC rate decreased dramatically and was not changed for several hours(incubation time). Also the incubation time increased as the ratio, $w_1/w_2$, get larger. We can explain these phenomena with the tensile stress that was caused by volume shrinkage due to the phase transformation from amorphous silicon to crystalline silicon.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.31-37
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• 2000

In the case of metal-induced lateral crystallization (MILC) for low temperature poly-Si TFT, offset length between Ni-thin film and the sides of gate could be modified to control the location of MILC boundary. Electrical characteristics were compared to analyze the effect of MILC boundary that was located either in or out of the channel region of the TFT. By removing the MILC boundary from channel region, on current, subthreshold slope and leakage current properties could be improved. When MILC boundary was located in the channel region, leakage current was reduced with electrical stress biasing. The amount of reduction increased as the channel width increased, but it was independent of the channel length.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.12
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• pp.29-34
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• 2000

The effects of electrical stress on MILC(Metal Induced Lateral Crystallization) poly-Si TFT were studied. After the electrical stress was applied on the TFT’s which were fabricated by MILC process, off-state(VG<0V) current was reduced by $10^2{\sim}10^4$ times. However, when the device on which electrical stress was applied was annealed in furnace, the off-state current increased as annealing temperature increased. From the dependence of off-state current on the post-annealing temperature, activation energy of the trap states in MILC poly-Si thin films was calculated to be 0.34eV.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.4
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• pp.25-30
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• 2000

Ion mass doping method has been implemented for the fabrication of large area electronic devices such as TFT-LCD. In this work, the effect of ion mass doping on the velocity and the behavior of MILC was investigated. When amorphous silicon was either doped or bombarded by accelerated ions, MILC velocity was reduced by over 50% and the front edge of MILC became coarse. In order to analyze the dependence of silicon film's properties on ion mass doping, ultraviolet reflectance and sulfate roughness were investigated. Both the velocity and the behavior of MILC were found to be related with the increase of surface roughness by ion bombardment.