To establish low-temperature process conditions, process-property correlation has been investigated for Ga-doped ZnO (GZO) thin films deposited by pulsed DC magnetron sputtering. Thickness of GZO films and deposition temperature were varied from 50 to 500 nm and from room temperature to 250 oC, respectively. Electrical properties of the GZO films initially improved with increase of temperature to 150 oC, but deteriorated subsequently with further increase of the temperature. At lower temperatures, the electrical properties improved with increasing thickness; however, at higher temperatures, increasing thickness resulted in deteriorated electrical properties. Such changes in electrical properties were correlated to the microstructural evolution, which is dependent on the deposition temperature and the film thickness. While the GZO films had c-axis preferred orientation due to preferred nucleation, structural disordering with increasing deposition temperature and film thickness promoted grain growth with a-axis orientation. Consequently, it was possible to obtain a good electrical property at relatively low deposition temperature with small thickness.

Ti films were deposited on glass substrates under various preparation conditions in a chamber of two-facing-target type dc sputtering; after deposition, the electric resistivity values were measured using a conventional four-probe method. Crystallographic orientations and microstructures, including the texture and columnar structure, were also investigated for the Ti films. The morphological features, including the columnar structures and surface roughness, are well explained on the basis of Thornton’s zone model. The electric resistivity and the thermal coefficient of the resistivity vary with the sputtering gas pressure. The minimum value of resistivity was around 0.4 Pa for both the 0.5 μm and 3.0 μm thick films; the apparent tendencies are almost the same for the two films, with a small difference in resistivity because of the different film thicknesses. The films deposited at high gas pressures show higher resistivities. The maximum of TCR is also around 0.4 Pa, which is the same as that obtained from the relationship between the resistivity and the gas pressure. The lattice spacing also decreases with increasing sputtering gas pressure for both the 0.5 μm and 3.0 μm thick films. Because they are strongly related to the sputtering gas pressures for Ti films that have a crystallographic anisotropy that is different from cubic symmetry, these changes are well explained on the basis of the film microstructures. It is shown that resistivity measurement can serve as a promising monitor for microstructures in sputtered Ti films.

Various thicknesses of Al-doped ZnO (AZO) films were deposited on glass substrate using pulsed dcmagnetron sputtering with a cylindrical target designed for large-area high-speed deposition. The structural,electrical, and optical properties of the films of various thicknesses were characterized. All deposited AZO filmshave (0002) preferred orientation with the c-axis perpendicular to the substrate. Crystal quality and surfacemorphology of the films changed according to the film thickness. The samples with higher surface roughnessexhibited lower Hall mobility. Analysis of the measured data of the optical band gap and the carrierconcentration revealed that there were no changes for all the film thicknesses. The optical transmittances weremore than 85% regardless of film thickness within the visible wavelength region. The lowest resistivity,4.13×10-4Ω·cm-1, was found in 750nm films with an electron mobility (µ) of 10.6cm2V-1s-1 and a carrierconcentration (n) of 1.42×1021cm-3.

Indium Gallium Zinc Oxide (IGZO) thin films were deposited onto 300 nm-thick oxidized Si substrates and glass substrates by direct current (DC) magnetron sputtering of IGZO targets at room temperature. FESEM and XRD analyses indicate that non-annealed and annealed IGZO thin films exhibit an amorphous structure. To investigate the effect of an annealing treatment, the films were thermally treated at 300˚C for 1hr in air. The IGZO TFTs structure was a bottom-gate type in which electrodes were deposited by the DC magnetron sputtering of Ti and Au targets at room temperature. The non-annealed and annealed IGZO TFTs exhibit an Ion/Ioff ratio of more than 105. The saturation mobility and threshold voltage of nonannealed IGZO TFTs was 4.92×10-1cm2/V·s and 1.46V, respectively, whereas these values for the annealed TFTs were 1.49×10-1cm2/V· and 15.43V, respectively. It is believed that an increase in the surface roughness after an annealing treatment degrades the quality of the device. The transmittances of the IGZO thin films were approximately 80%. These results demonstrate that IGZO thin films are suitable for use as transparent thin film transistors (TTFTs).

Ni mono-silicide는 선폭이 0.15μm이하에서도 전기저항이 커지는 현상이 없고 Ni와 Si이 1:1로 반응하기 때문에 얇은 실리사이드의 제조가 가능하고 도펀트의 재분포 현상을 감소시킬수 있다. 따라서 0.15μm급 이하 디바이스에 사용이 기대되는 NiSi의 제조를 위한 Ni 박막의 증착조건 확보와 열처리 조건에 따른 NiSi의 기초 물성조사를 수행하였다. Ni mono-silicide는 sputter의 물리적 증착방법으로 Ni 박박을 증착후 관상로를 상용하여 150~1000˚C 온도 범위에서 제조하였다. 그후 SPM을 이용하여 각 시편의 표면조도를 측정하였고, 미세구조와 성분분석은 EDS가 장착된 TEM을 사용하여 측정하였다. 각 열처리 온도별 생성상의 전기적 성질은 4 point probe로 측정하였다. 본 연구의 결과, SPM은 비파괴 방법으로 NiSi가 NiSi2로 변태되었는지 확인할 수 있는 효과적인 공정모니터링 방법임을 확인하였고, 800˚C이상 공온 열처리에 잔류 Ni의 산화방지를 의해 산소분압의 제어가 Po2=1.5±10(sup)-11색 이하가 되어야 함을 알 수 있었으며, 전지적 특성실험으로부터 본 연구에서 제조된 박막의 NiSi→NiSi2 상태변온도는 700˚C라고 판단되었다.

Ti-6Al-4V 합금을 타겟트로 사용하여 유리 기판위에 dc reactive magnetron sputtering법으로 N2/(Ar+N2) 비, 기전력 및 시간등의 여러 가지 증착 조건에서 Ti-6Al-4V-N 필름을 증착하였고, 각각의 증착 조건에 따른 결정구조 및 우선방위 거동은 X-선 회절장치를 사용하여 조사하였다. Ti-6Al-4V-N 필름은 본질적으로 fcc 결정구조의 δ-TiN에 Al과 V이 결함으로서 고용된 변형된 형태의 δ-TiN구조이고, TiN의 격자상수(4.240 )보다 작은 값을 나타내었는데, 이는 Ti(1.47 )에 비하여 상대적으로 원자반경이 작은 Al(1.43 )과 V (1.32 )이 Ti의 격자위치에 치환된 결과이다. 그리고 Ti-6Al-4V-N 필름은 N2가스 분압이 감소됨에 따라 (111) 우선방위 성장거동을 하였을 뿐만아니라 증착시간의 증가에 따라 뚜렷한 (111) 우선방위 성장거동을 나타내었다. 그리고 증착속도 및 결정입도의 거동 또한 여러 가지 증착 조건에 크게 의존한다

DC마그네트론 스퍼터링 방식으로 Ti/SiO2/Si 구조 위에 Pt(200) 박막을 배향 성장시키기 위해 증착조건(스퍼터링 가스의 종류와 압력, 기판의 온도)과 후속열처리(RTA, Furnace annealing)에 따른 Pt 박막의 전기, 결정학적 특성을 조사하였다. 실험결과, 20mTorr의 Ar+O2(20%)의 혼합가스 분위기에서 기판온도를 500˚C로 유지하여 Pt박막을 증착하고 600˚C에서 30초간 급속 열처리를 실시한 경우, 90% 이상의 결정 배항도를 갖는 Pt(200) 박막을 제작할 수 있었다. 제작된 Pt(200) 박막은 30~40μΩ.cm의 낮은 전기저항율과 우수한 열적 안정성을 나타내었으며 600˚C의 고온에서 장시간 열처리를 실시하여도 전기저항율이나 우선 배향성의 변화, 박막내 미세 결함 및 열적응집현상 등이 발생되지 않았다.