• Korean Journal of Materials Research
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• v.10 no.2
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• pp.124-127
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• 2000

A new triode type Ti-silicided Si FEA(field emitter array) was realized by Ti-silicidation of Ti coated Si FEA and its field emission properties were investigated. In the fabricated device, the field emission properties through the unit pixel with $200{\mu\textrm{m}}{\times}200{$\mu\textrm{m}}$ tip array in the area of $1000{\mu\textrm{m}}{\times}1000{$\mu\textrm{m}}$ were as follows : the turn-on voltage was about 70V under high vacuum condition of $10^8Torr$, and the field emission current and steady state current degradation were about 2nA/tip and 0.3%/min under the bias of $V_A=500V\;and\;V_G=150V$. The low turn-on voltage and the high current stability during long term operation of the Ti silicided Si FEA were due to the thermal and chemical stability and the low work function of silicide layer formed at the surface of Si tip.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.31-32
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• 2005

Ge 농도가 30%인 SiGe 위에 Ni-Pd 합금을 이용한 새로운 Ni-Germanosilicide의 방법을 제안하여 열안정성 향상에 대해 연구하였다. 새롭게 제안한 Ni-Pd 합금을 이용하여 3 가지 구조 (Ni-Pd, Ni-Pd/TiN, Ni-Pd/Co/TiN) 중 Cobalt 다층구조를 사용한 구조 (Ni-Pd/Co/TiN)가 면저항이 가장 낮고 안정한 silicide 특성을 갖는 것을 나타냈으며, 고온열처리 $700^{\circ}C$, 30분에서도 낮고 안정한 면저항 특성을 유지시켜 열안정성을 개선하였다.

• Korean Journal of Materials Research
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• v.10 no.12
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• pp.812-818
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• 2000

We studied the effects of Ge preamorphization (PAM) on 0.25$\mu\textrm{m}$ Ti-salicide junctions using comparative study with As PAM. For each PAM schemes, ion implantations are performed at a dose of 2E14 ion/$\textrm{cm}^2$ and at 20keV energy using $^{75}$ /As+and GeF4 ion sources. Ge PAM showed better sheet resistance and within- wafer uniformity than those of As PAM at 0.257m line width of n +/p-well junctions. This attributes to enhanced C54-silicidation reaction and strong (040) preferred orientation of the C54-silicide due to minimized As presence at n+ junctions. At p+ junctions, comparable performance was obtained in Rs reduction at fine lines from both As and Ge PAM schemes. Junction leakage current (JLC) revels are below ~1E-14 A/$\mu\textrm{m}^{2}$ at area patterns for all process conditions, whereas no degradation in JLC is shown under Ge PAM condition even at edge- intensive patterns. Smooth $TiSi_2$ interface is observed by cross- section TEM (X- TEM), which supports minimized silicide agglomeration due to Ge PAM and low level of JLC. Both junction break- down voltage (JBV) and contact resistances are satisfactory at all process conditions.

• Korean Journal of Materials Research
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• v.4 no.2
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• pp.143-151
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• 1994

On PT/Ti/Si substrates, PZT thln fllms are deposited at $300^{\circ}C$ by rf magnetron sputtering uslng a $(PbZr_{52}, Ti_{48})O_{3}$ composltc cerarnlc target. To abtaln, the stable phase, perovskltc structure, furnace annealmg techmque had been cmplo:~d In PbO amb~ent for the $550^{\circ}C$-$750^{\circ}C$ temperature ranges. On Pt(250$\AA$)/Ti(500$\AA$)/Si, Pt(1000)$\AA$/Ti(500$\AA$)/Si substrates, effects of Ti layer and Pt thickness are studled. Though thickness of the Pt layer 1s 1000$\AA$). oxygen diffusion is not prevented and accelerated by Ti layer actlng for oxygen sink sites durmg furnace annealing. The upper TI layer 1s transformed Into TIOX by oxyen dlffuslon and lower Ti layer Into silicide with in-diffused Pt. The formation of TiOx layer seems to affect the orlentatton of the PZT layer. Furnace annealed f~lm shows ferroelectr~c and electrical properties wth a remanent polarlzation of 3.3$\mu A /\textrm{cm}^2$, , coerclve fleld of 0.15MV/cm, a=571 (10kHz), leakage current 32.65$\mu A /\textrm{cm}^2$, , breakdown voltage of 0.4OMV/cm.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.215-220
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• 2001

Amorphous Ti-Si-N films of approximately 200 and 650 thickness were reactively sputtered on Si wafers using a dc magnetron sputtering system at various $N_2$/Ar flow ratios. Their barrier properties between Cu (750 ) and Si were investigated by using sheet resistance measurements, XRD, SEM, RBS, and AES depth profiling focused on the effect of the nitrogen content in Ti-Si-N thin film on the Ti-Si-N barrier properties. As the nitrogen content increases, first the failure temperature tends to increase up to 46 % and then decrease. Barrier failure seems to occur by the diffusion of Cu into the Si substrate to form Cu$_3$Si, since no other X- ray diffraction intensity peak (for example, that for titanium silicide) than Cu and Cu$_3$Si Peaks appears up to 80$0^{\circ}C$. The optimal composition of Ti-Si-N in this study is $Ti_{29}$Si$_{25}$N$_{46}$. The failure temperatures of the $Ti_{29}$Si$_{25}$N$_{465}$ barrier layers 200 and 650 thick are 650 and $700^{\circ}C$, respectively.ely.

• Korean Journal of Materials Research
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• v.8 no.6
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• pp.499-504
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• 1998

For the formation of cobalt polycide gate electrode, CoSi, was grown on columnar poly-Si, granular poly-Si or amorphous Si by depositing either Co monolayer or Co/Ti bilayer and its thermal stability was compared to study effects of the substrate crystallinity and the silicide formation method. When specimens were rapidly heat-treated at 90$0^{\circ}C$ up to 600 seconds, using amorphous Si or Co/Ti on all substrates improved the thermal stability. This was attributed to the uniform chemical composition of initial CoSi, and its smooth interface with the substrates, induced by smooth and clean Si surface and delayed Co diffusion. The main factors determining the thermal stability were found to be composition uniformity and smooth interface of $CoSi_2$, intially formed at the early stage of the heat-treatment.

• Korean Journal of Materials Research
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• v.3 no.2
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• pp.158-165
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• 1993

Abstract To investigate the effect of underlying Si on the thermal stability of the TiS$i_2$ film, TiS$i_2$ films obtained by the solid-state reaction of the Ti film on as-deposited or on heat-treated poly-silicon and amorphous-silicon were annealed at 90$0^{\circ}C$ for various times. The poly-Si film was evaluated by XRD, SEM and TEM. The thermal stability of the TiS$i_2$ film was evaluated by measuring the sheet resistance and microstructural evolution during furnace annealing. Agglomeration of the TiSi, film occurred more on amorphous-Si than on poly-Si. The thermal stability of the TiS$i_2$ film was improved by annealing poly-Si. The Si layer crystallized from amorphous-Si has an equiaxed structure with the (111) preferred orientation whereas for as-deposited poly-Si has a columnar structure with the (110) orientation. Better thermal stability of the TiS$i_2$ film can be obtained by the higher surface energy of underlying poly-Si.

• Korean Journal of Materials Research
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• v.30 no.6
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• pp.301-307
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• 2020

In this study, factors considered to be causes of promotion of densification of sintered pellets identified during phase change are reviewed. As a result, conclusions shown below are obtained for each factor. In order for MA powder to soften, a temperature of 1,000 K or higher is required. In order to confirm the temporary increase in density throughout the sintered pellet, the temperature rise due to heat during phase change was found not to have a significant effect. While examining the thermal expansion using the compressed powder, which stopped densification at a temperature below the MA powder itself, and the phase change temperature, no shrinkage phenomenon contributing to the promotion of densification is observed. The two types of powder made of Ti-silicide through heat treatment are densified only in the high temperature region of 1,000 K or more; it can be estimated that this is the effect of fine grain superplasticity. In the densification of the amorphous powder, the dependence of sintering pressure and the rate of temperature increase are shown. It is thought that the specific densification behavior identified during the phase change of the Ti-37.5 mol.%Si composition MA powder reviewed in this study is the result of the acceleration of the powder deformation by the phase change from non-equilibrium phase to equilibrium phase.

• Korean Journal of Materials Research
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• v.8 no.3
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• pp.189-194
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• 1998

The redistribution behavior of boron during Co silicidation annealing in the Co/metal/Si system was investigated using SIMS. Ti, Nb and Hf films were used as epitaxy promoting metal layers. After annealing treatment the boron peak height was about 1 order lowered in Co/Ti/Si and Co/Nb/Si systems but the relative peak position from the surface did not change. The distribution of boron was very similar to those of Ti and Nb, because of the strong affinities of boron with them. Also, the position of the main boron peak in the Co/Hf/Si system was almost the same as that of Hf, but the distribution feature of the Co/Hf/Si system somewhat differed from those of Co/Ti/Si and Co/Nb/Si systems. This implies that the affinity between B and Hf is weaker than those of B-Ti and B-Nb. Boron tends to be depleted at the silicidelsi interface while it tends to be piled-up at the Co-metal/Co silicide interface during silicidation annealing.

• Korean Journal of Materials Research
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• v.4 no.1
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• pp.81-89
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• 1994

Ti film of lOnm thickness and Co film of 18nm thickness were sequentially e-heam evaporated onto Si (100) substrates. Metal deposited samples were rapidly thermal-annt.aled(KTA) in thr N1 en vironment a t $900^{\circ}C$ for 20 sec. to induce the reversal of metal bilayer, so that $CoSi_{2}$ thin films could be formed. The sheet resistance measured by the 4-point probe was 3.9 $\Omega /\square$This valur was maintained with increase in annealing time upto 150 seconds, showing high thermal stab~lity. Thc XRII spectra idrn tified the silicide film formed on the Si substrate as a $CoSi_{2}$ epitaxial layer. The SKM microgr;iphs showed smooth surface, and the cross-sectional TKM pictures revealed that the layer formed on the Si substrate were composed of two Co-Ti-Si alloy layers and 70nm thick $CoSi_{2}$ epl-layer. The AES analysis indicated that the native oxide on Si subs~rate was removed by TI ar the beginning of the RTA, and Ihcn that Co diffused to clean surface of Si substrate so that epitaxial $CoSi_{2}$ film could bt, formed. In thc rasp of KTA at $700^{\circ}C$. 20sec. followed by $900^{\circ}C$, 20sec., the thin film showed lower sheet resistance, but rough surface and interface owing to $CoSi_{2}$ crystal growth. The application scheme of this $CoSi_{2}$ epilayer to VLSI devices and the thermodynarnic/kinetic mechan~sms of the $CoSi_{2}$ epi-layer formation through the reversal of Co/Ti bdayer were discussed.