• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2000.04a
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• pp.103-108
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• 2000

The texture of Al/Ti thin films deposited on low-dielectric polymer substrates has been investigated. Fifty-nm-thick Ti films and 500-nm-thick Al-1%Si-0.5%Cu (wt%) films were deposited sequentially onto low-k polymers and SiO$_2$ by using a DC magnetron sputtering system. The texture of Al thin film was determined using X-ray diffraction (XRD) theta-2theta ($\theta$-2$\theta$) and rocking curve and the microstructure of Al/Ti films on low-k polymer and SiO$_2$ substrates was characterized by Transmission electron microscopy (TEM). hall thin films deposited on SiO$_2$ had stronger texture than those deposited on low-k polymer. The texture of Al thin films strongly depended on that of Ti films. Cross-sectional TEM resealed that Brains of Ti films on SiO$_2$ substrates had grown perpendicular to the substrate, while the grains of Ti films on SiLK substrates were farmed randomly. The lower degree of 111 texture of Al thin films on low-k polymer was due to Ti underlayer.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.2
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• pp.37-42
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• 2000

The comparative study of texture of Al/Ti thin films deposited on low-dielectric polymer and $SiO_2$substrates has been investigated. Fifty-nm-thick Ti films and 500-nm-thick Al-1%Si-0.5%Cu (wt%) films were deposited sequentially onto low-k polymers and $SiO_2$by using a DC magnetron sputtering system. The texture of Al thin film was determined using X-ray diffraction (XRD) theta-2theta ($\theta$-2$\theta$) and rocking curve and the microstructure of Al/Ti films on low-k polymer and $SiO_2$substrates was characterized by cross-sectional transmission electron microscopy (TEM). Both the $\theta$-2$\theta$ method and rocking curve measurement suggest that Al/Ti thin films deposited on $SiO_2$have stronger texture than those deposited on low-k polymer. The texture of Al thin films strongly depended on that of Ti films. Cross-sectional TEM revealed that grains of Ti films on $SiO_2$substrates had grown perpendicular to the substrate, while the grains of Ti alms on SiLK substrates were formed randomly. The lower degree of (111) texture of Al thin films on low-k polymer was due to Ti underlayer.

• Corrosion Science and Technology
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• v.9 no.2
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• pp.81-86
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• 2010

The mechanisms of selective oxidation of intercritically annealed CMnAl TRIP steels in a Continuous Galvanizing Line (GCL) were studied by cross-sectional observation of the surface and sub-surface regions by means of High Resolution Transmission Electron Microscopy (HR-TEM). The selective oxidation and nitriding of an intercritically annealed CMnAl TRIP steel in a controlled dew point 10%$H_2+N_2$ atmosphere resulted in the formation of c-xMnO.$MnO_2$ (1${\leq}$x<3) and c-xMnO.$Al_2O_3$ ($x{\geq}1$) particles on the steel surface. Single crystal c-xMnO.$SiO_2$ ($2{\leq}x{\leq}4$) oxide particles were also observed on the surface. A thin film of crystalline c-xMnO.$SiO_2$ (2${\leq}$x<3) and c-xMnO.$Al_2O_3$ ($x{\geq}1$) was present between these particles. In the sub-surface region, internal oxidation, nitriding and intermetallic compound formation were observed. In the first region, large crystalline c-xMnO.$SiO_2$ ($1{\geq}x{\geq}2$) and c-xMnO.$Al_2O_3$ ($x{\geq}1$) oxides particles were present. In the second region, c-AlN particles were observed, and in a third region, small $MnAl_x$ (x>1) intermetallic compound particles were observed.

• Korean Journal of Materials Research
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• v.30 no.5
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• pp.262-266
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• 2020

In this paper, we investigated the effect of the passivation stack with Al₂O₃, hydrogenated silicon nitride (SiN_x:H) stack and Al₂O₃, silicon oxynitride (SiON_x) stack in the n type bifacial solar cell on monocrystalline silicon. SiNx:H and SiON_x films were deposited by plasma enhanced chemical vapor deposition on the Al₂O₃ thin film deposited by thermal atomic layer deposition. We focus on passivation properties of the two stack structure after laser ablation process in order to improve bifaciality of the cell. Our results showed SiN_x:H with Al₂O₃ stack is 10 mV higher in implied open circuit voltage and 60 ㎲ higher in minority carrier lifetime than SiON_x with Al₂O₃ stack at Ni silicide formation temperature for 1.8% open area ratio. This can be explained by hydrogen passivation at the Al₂O₃/Si interface and Al₂O₃ layer of laser damaged area during annealing.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.12
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• pp.924-928
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• 2010

In this study, $HfAlO_3$ thin films using gate insulator of MOSFET were etched in inductively coupled plasma. The etch characteristics of the $HfAlO_3$ thin films has been investigated by varying $O_2/BCl_3$/Ar gas mixing ratio, a RF power, a DC bias voltage and a process pressure. As the $O_2$ concentration increases further, $HfAlO_3$ was redeposited. As increasing RF power and DC bias voltage, etch rates of the $HfAlO_3$ thin films increased. Whereas, as decreasing of the process pressure, etch rates of the $HfAlO_3$ thin films increased. The chemical reaction on the surface of the etched the $HfAlO_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS). These peaks moved a binding energy. This chemical shift indicates that there are chemical reactions between the $HfAlO_3$ thin films and radicals and the resulting etch by-products remain on the surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.9
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• pp.681-685
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• 2012

We investigated the dry etching characteristics of TiN in $TiN/Al_2O_3$ gate stack using a inductively coupled plasma system. TiN thin film is etched by BCl3/He plasma. The etching parameters are the gas mixing ratio, the RF power, the DC-bias voltages and process pressures. The highest etch rate is in $BCl_3/He$ (25%:75%) plasma. The selectivity of TiN thin film to $Al_2O_3$ is pretty similar with $BCl_3/He$ plasma. The chemical reactions of the etched TiN thin films are investigated by X-ray photoelectron spectroscopy. The intensities of the Ti 2p and the N 1s peaks are modified by $BCl_3$ plasma. Intensity and binding energy of Ti and N could be changed due to a chemical reaction on the surface of TiN thin films. Also we investigated that the non-volatile byproducts such as $TiCl_x$ formed by chemical reaction with Cl radicals on the surface of TiN thin films.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.100-100
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• 2000

Aluminium oxide (Al2O3) films have been investigated for many applications such as insulating materials, hard coatings, and diffusion barriers due to their attractive electrical and mechanical properties. In recent years, application of Al2O3 films for dielectric materials in integrated circuits as gates and capacitors has attracted much attention. Various deposition techniques such as sol-gel, metalorganic decomposition (MOD), sputtering, evaporation, metalorganic chemical vapor deposition (MOCVD), and pulsed laser ablation have been used to fabricate Al2O3 thin films. Among these techniques, reactive sputtering has been widely used due to its high deposition rate and easy control of film composition. It has been also reported that the sputtered Al2O3 films exhibit superior chemical stability and mechanical strength compared to the films fabricated by other processes. In this study, Al2O3 thin films were deposited on Pt/Ti/SiO/Si2 and Si substrates by DC reactive sputtering at room temperature with variation of the Ar/O2 ratio in sputtering ambient. Crystalline phase of the reactively sputtered films was characterized using X-ray diffractometry and the surface morphology of the films was observed with Scanning election microscopy. Effects of Th Ar/O2 ratio characteristics of Al2O3 films were investigated with emphasis on the thickness dependence of the dielectric properties. Correlation between the dielectric properties and the microstructure was also studied

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.213-213
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• 2010

We investigated the RF sputtering conditions for the deposition of AZO (Al doped ZnO) transparent conducting film on PET using the roll to roll vacuum coater. AZO thin films, sputtered at the various RF powers and working pressures, were studied for their structural, electrical and optical properties.. From the X-Ray diffraction patterns, we calculated the lattice stress using the Bragg equation. The compressive stress tends to decrease with the increase in film thickness. AZO thin film with the thickness of 152nm (1400W, 0.4Pa) exhibit the resistivity of $3.92*10-3{\Omega}/cm$ and the transmittance of 96.9% at 550nm.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.620-621
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• 2008

Transparent electronics has been one of the key terminologies forecasting the ubiquitous technology era. Several researchers have thus extensively developed transparent oxide-based thin-film transistors (TFTs) on glass and plastic substrates although in general high voltage operating devices have been mainly studied considering transparent display drivers. However, low voltage operating oxide TFTs with transparent electrodes are very necessary if we are aiming at logic circuit applications, for which transparent complementary or one-type channel inverters are required. The most effective and low power consuming inverter should be a form of complementary p-channel and n-channel transistors but real application of those complementary TFT inverters also requires electrical- and even photo-stabilities. Since p-type oxide TFTs have not been developed yet, we previously adopted organic pentacene TFTs for the p-channel while ZnO TFTs were chosen for n-channel on sputter-deposited $AlO_x$ film. As a result, decent inverting behavior was achieved but some electrical gate instability was unavoidable at the ZnO/$AlO_x$ channel interface. Here, considering such gate instability issues we have designed a unique transparent complementary TFT (CTFTs) inverter structure with top n-ZnO channel and bottom p-pentacene channel based on 12 nm-thin nano-oxide/self assembled monolayer laminated dielectric, which has a large dielectric strength comparable to that of thin film amorphous $Al_2O_3$. Our transparent CTFT inverter well operate under 3 V, demonstrating a maximum voltage gain of ~20, good electrical and even photoelectric stabilities. The device transmittance was over 60 % and this type of transparent inverter has never been reported, to the best of our limited knowledge.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.57-60
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• 2009

Transparent electrode ZnO:Al(AZO)films were deposited on a PES (polyethersulfone) polymer substrate for thin film solar cells applications. A PES substrate with a thickness of 0.2mm and transmittance > 90% in the visible range was used because it is light weight and can deform easily. AZO thin films were prepared at a fixed DC power, $PO_2\;=\;P(O_2)/[P(O_2)\;+\;P(Ar)]$, and various substrate temperatures. The properties of AZO thin films were examined by X-ray diffraction, UV/VIS spectroscopy, four-point probe, Hall measurements, and field emission scanning electron microscopy. The lowest resistivity of all the films was $4.493\;{\times}\;10^{-4}\;[\Omega-cm]$ and the transmittance was > 80% in the visible range.