• 한국재료학회지
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• 제2권1호
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• pp.27-34
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• 1992

Tantalum silicide films are prepared from a composite $TaSi_{28}$ target source and subjected to rapid thermal annealing($500-1100^{\circ}C$, 20sec) in Ar ambient. The formation and the properties of tantalum silicides have been investigated by using 4-point probe, x-ray diffraction, scanning electron microscope(SEM), Auger electron spectroscope(AES), and ${\alpha}$-step. It has been found that the sample annealed above $700^{\circ}C$ forms a polycrystalline $TaSi_2$ phase, and grains grow in granular form regardless of the kind of substrates. The mechanism of the formation of tantalum silicide is the nucleation and growth by Ta-Si short range reaction. The tantalum silicide film has the relatively low resistivity($70-72.5{\mu}{\Omega}-cm$) and smooth surface roughness.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 춘계학술대회 논문집 반도체재료
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• pp.79-83
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• 2001

In order to compare the barrier properties of Ta-N/Si(001) with those of Ta-N/Ta/Si(001), we studied structural properties of films grown by RF magnetron sputtering with various $Ar/N_2$ ratios. To evaluate the barrier properties, the samples were annealed in a vacuum chamber. Ex-situ x-ray scattering measurements were done using an in-house x-ray system. With increasing nitrogen ratio in Ta-N/Si(001), the barrier property of Ta-N/Si(001) was enhanced, finally failed at $750^{\circ}C$ due to the crystallization and silicide formation. Compared with Ta-N/Si(001), Ta-N/Ta/Si(001) forms silicides at $650^{\circ}C$. However it does not crystallize even at $750^{\circ}C$. With increasing nitrogen composition in Ta-N/Ta/Si(001), the formation of tantalum silicide was reduced and the surface roughness was improved. To observe the surface morphology of Ta-N/Ta/Si(001) during annealing, we performed an in-situ x-ray scattering experiment using synchrotron radiation of the 5C2 at Pohang Light Source(PLS). Addition of Ta layer between Ta-N and Si(001) improved the surface morphology and reduced the surface degradation at high temperatures. In addition, increasing $N_2/Ar$ flow ratio reduced the formation of tantalum silicide and enhanced the barrier properties.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2000년도 추계총회,초청강연,특별강연,연구발표회
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• pp.159.2-159
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• 2000

• 한국재료학회지
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• 제1권2호
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• pp.99-104
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• 1991

Ta-silicide의 게이트 전극 및 비트라인(bit line)으로의 사용가능성을 알아보기 위하여 As, P, $BF_2$가 $5{\times}10^15cm^-2$의 농도로 이온주입된 다결정 실리콘에 탄탈륨을 스퍼터링으로 증착한 후 급속 열처리로 Ta-silicide를 형성하였다. 형성된 Ta-silicide의 특성은 4-탐침법, X-rayghlwjf, SEM 단면사진과 ${\alpha}$-step으로 조사하였으며, 불순물들의 거동은 Secondary Ion Mass Spectroscopy(SIMS)로 알아보았다. $TaSi_2$의 형성은 $800^{\circ}C$에서 시작하며 $1000^{\circ}C$ 이상에서 완료됨을 알았다. 형성된 $TaSi_2$층으로 out-diffusion 하였다.

• 한국재료학회지
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• 제1권1호
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• pp.17-22
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• 1991

불순물이 주입된 실리콘 기판에 500 두께의 탄탈륨 박막을 증착한 후 실리사이드를 형성시키기 위해 아르곤 분위기에서 급속열처리(RTA)률 하였다. 형성된 $TaSi_2$와 불순물의 거동은 XRD, SEM, 4-point probe, HP4145와 SIMS로 조사하였다. 불순물의 종류에 관계없이 $TaSi_2$는 RTA 온도가 $800^{\circ}C$일때 형성되기 시작하였으며 $1000^{\circ}C$이상에서 증착된 Ta가 전부 $TaSi_2$로 상 전이가 일어났다. 또한 $TaSi_2/P^+$영역에 대한 접촉저항간은 contact size가 $0.9{\times}0.9({\mu}{m^2}$)일때 $22{\Omega}$ 낮은값을 가졌으며 이온 주입된 불순물은 RTA처리시 형성된 $TaSi_2$층으로 out-diffusion이 일어났다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.362-362
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• 2014

Atomic layer deposition (ALD) can be regarded as a special variation of the chemical vapor deposition method for reducing film thickness. ALD is based on sequential self-limiting reactions from the gas phase to produce thin films and over-layers in the nanometer scale with perfect conformality and process controllability. These characteristics make ALD an important film deposition technique for nanoelectronics. Tantalum pentoxide ($Ta_2O_5$) has a number of applications in optics and electronics due to its superior properties, such as thermal and chemical stability, high refractive index (>2.0), low absorption in near-UV to IR regions, and high-k. In particular, the dielectric constant of amorphous $Ta_2O_5$ is typically close to 25. Accordingly, $Ta_2O_5$ has been extensively studied in various electronics such as metal oxide semiconductor field-effect transistors (FET), organic FET, dynamic random access memories (RAM), resistance RAM, etc. In this experiment, the variations of chemical and interfacial state during the growth of $Ta_2O_5$ films on the Si substrate by ALD was investigated using in-situ synchrotron radiation photoemission spectroscopy. A newly synthesized liquid precursor $Ta(N^tBu)(dmamp)_2$ Me was used as the metal precursor, with Ar as a purging gas and $H_2O$ as the oxidant source. The core-level spectra of Si 2p, Ta 4f, and O 1s revealed that Ta suboxide and Si dioxide were formed at the initial stages of $Ta_2O_5$ growth. However, the Ta suboxide states almost disappeared as the ALD cycles progressed. Consequently, the $Ta^{5+}$ state, which corresponds with the stoichiometric $Ta_2O_5$, only appeared after 4.0 cycles. Additionally, tantalum silicide was not detected at the interfacial states between $Ta_2O_5$ and Si. The measured valence band offset value between $Ta_2O_5$ and the Si substrate was 3.08 eV after 2.5 cycles.

• 마이크로전자및패키징학회지
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• 제17권2호
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• pp.55-61
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• 2010

탄탈륨실리사이드 히터가 내장된 소자를 Ag 페이스트와 Au SBB(Stud Bump Bonding)를 이용하여 Au가 코팅 된 기판에 각각 접합 하였다. 전단 테스트와 전류를 흐르면서 열 성능을 측정하였다. Au 스터드 범프 본딩의 최적 플립칩 접합조건은 전단 후 파괴면 관찰하여 설정하였으며, 기판 온도를 $350^{\circ}C$, 소자 온도를 $250^{\circ}C$에서 하중을 300 g/bump 로 하여 접합하는 경우가 최적 조건이였다. 히터에 5 W 인가시 소자의 온도는 Ag 페이스트를 이용한 접합의 경우 최대 온도는 약 $50^{\circ}C$이었으며, Au 금속층을 갖고 있는 실리콘 기판에 Au 스터드 본딩으로 접합된 인 경우 약 $64^{\circ}C$를 나타내었다. 기판과의 접촉면적이 와이어본딩과 Au 스터드 범프 본딩 가 약 300배가 차이가 나는 경우 약 $14^{\circ}C$ 차이를 나타내었고, 전사모사를 통하여 접합면의 접촉저항이 중요한 이유임을 알 수 있었다.