• Journal of the Korean Vacuum Society
• /
• v.19 no.4
• /
• pp.287-292
• /
• 2010

We have investigated the effects of oxygen flow ratios on the structural, morphological, and optical properties of AlN thin films grown by using radio-frequency reactive magnetron sputtering. The AlN thin films were deposited at $300^{\circ}C$ of substrate temperature, and the reactive gas were supplied with both nitrogen and oxygen. The oxygen flow ratio was varied by controlling the amount of oxygen with respect to the total mixed gases, 0%, 10%, 15%, 20%, 25%, and 30%. The structural, morphological, and optical properties of the deposited AlN thin films were examined by using X-ray diffractometer, scanning electron microscopy, and ultraviolet-visible spectrophotometer. The AlN thin film grown at 10% of oxygen flow ratio indicated an average transmittance of 91.3% in the wavelength range of 350~1,100 nm and an optical band gap of 4.30 eV. The experimental results suggest that AlN thin films can be deposited optionally by varying the oxygen flow ratio.

• Transactions of Materials Processing
• /
• v.28 no.1
• /
• pp.43-48
• /
• 2019

Aluminum nitride (AlN) is used by the semiconductor industry, and is a compound that is required when manufacturing high thermal conductivity. The AlN films with c-axis orientation and thermal conductivity characteristic were deposited by using the Pulsed Laser Deposition (PLD). The AlN thin films were characterized by changing the deposition conditions. In particular, we have researched the AlN thin film deposited under optimal conditions for growth atmosphere. The epitaxial AlN films were grown on sapphire ($c-Al_2O_3$) single crystals by PLD with AlN target. The AlN films were deposited at a fixed temperature of $650^{\circ}C$, while conditions of nitrogen ($N_2$) pressure were varied between 0.1 mTorr and 10 mTorr. The quality of the AlN films was found to depend strongly on the $N_2$ partial pressure that was exerted during deposition. The X-ray diffraction studies revealed that the integrated intensity of the AlN (002) peak increases as a function the corresponding Full width at half maximum (FWHM) values decreases with lowering of the nitrogen partial pressure. We found that highly c-axis orientated AlN films can be deposited at a substrate temperature of $650^{\circ}C$ and a base pressure of $2{\times}10^{-7}Torr$ in the $N_2$ partial pressure of 0.1 mTorr. Also, it is noted that as the $N_2$ partial pressure decreased, the thermal conductivity increased.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.346-347
• /
• 2007

Aluminum nitride (AlN) thin films were deposited on Polycrystalline (poly) 3C-SiC buffer layers using pulsed reactive magnetron sputtering. Characteristics of AlN films were investigated experimentally by means of FE-SEM, X-ray diffraction, and FT-IR, respectively. As a result, highly (002) oriented AlN thin films with almost free residual stress were achieved using 3C-SiC buffer layers. Therefore, AlN thin films grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.

• Electrical & Electronic Materials
• /
• v.10 no.7
• /
• pp.706-712
• /
• 1997

AlN(Aluminium Nitride) thin films were prepared using by RF sputtering method on the Si(100) and Si(111) substrates as the parameters of the substrate temperature, RF power, sputtering duration and the $N_2$/Ar ratio and investigated by X-ray diffraction, IR spectrometry, n&k analyzer. For the Si(100) substrate, the AlN thin films of (101) orientation were obtained under the conditions of room temperature and the nitrogen of 60 vol.%. For the Si(111) substrate, the (002) AlN thin films were obtained under the nitrogen of 100 vol.%. In case of the thin film prepared in the condition of above 60 vol.% of the nitrogen, the average value of the surface roughness of the film was 151$\AA$. From the changes of the half widths of E$_1$[TO] phonon bands at the wavenumber of 680$cm^{-1}$ /, it were compared of the crystallinities of the films which were grown under the different conditions. The thicknesses of AlN films were decreased dramatically in the region of the nitrogen of 40~60 vol.%. Its due to the nitridation of the Al target surface and getting low of the sputtering yield by the $N_2$/Ar ratio being increased.

• Journal of Sensor Science and Technology
• /
• v.16 no.6
• /
• pp.462-466
• /
• 2007

Aluminum nitride (AlN) thin films were deposited on Si substrates by using polycrystalline (poly) 3C-SiC buffer layers, in which the AlN film was grown by pulsed reactive magnetron sputtering. Characteristics of grown AlN films were investigated experimentally by means of FE-SEM, X-ray diffraction, and FT-IR, respectively. The columnar structure of AlN thin films was observed by FE-SEM. X-ray diffraction pattern proved that the grown AlN film on 3C-SiC layers had highly (002) orientation with low value of FWHM (${\Theta}=1.3^{\circ}$) in the rocking curve around (002) reflections. These results were shown that almost free residual stress existed in the grown AlN film on 3C-SiC buffer layers from the infrared absorbance spectrum. Therefore, the presented results showed that AlN thin films grown on 3C-SiC buffer layers can be used for various piezoelectric fields and M/NEMS applications.

• Journal of the Korean Vacuum Society
• /
• v.10 no.1
• /
• pp.22-26
• /
• 2001

Microstructures of AlN thin films on Si substrates grown by plasma assisted molecular beam epitaxy were analyzed with various growth temperatures and substrate orientations. Reflection high energy electron diffraction (RHEED) patterns were checked for the in-situ monitoring of the growth condition. X-ray diffraction(XRD), double crystal X-ray diffraction (DCXD), and transmission electron microscopy/diffraction (TEM/TED) techniques were employed to characterize the microstructure of the films after growth. On Si(100) sub-strates, AlN thin films were grown mostly along the hexagonal c-axis orientation at temperature higher than $850^{\circ}C$. On the other hand the AlN films on Si(111) were epitaxially grown with directional coherencies in AlN(0001)/Si(111), AlN(1100)/Si(110), and AlN(1120)/Si(112). The microstructure of AlN thin films on Si(111) substrates, with a full width at half maximum of almost 3000 arcsec at 2$\theta$=$36.2^{\circ}$, showed that the single crystal films were grown, even if they includ a lot of crystal defects such as dislocations and stacking faults.

• Korean Journal of Materials Research
• /
• v.31 no.12
• /
• pp.697-703
• /
• 2021

Aluminum nitride having a dense hexagonal structure is used as a high-temperature material because of its excellent heat resistance and high mechanical strength; its excellent piezoelectric properties are also attracting attention. The structure and residual stress of AlN thin films formed on glass substrate using TFT sputtering system are examined by XRD. The deposition conditions are nitrogen gas pressures of 1 × 10^-2, 6 × 10^-3, and 3 × 10^-3, substrate temperature of 523 K, and sputtering time of 120 min. The structure of the AlN thin film is columnar, having a c-axis, i.e., a <00·1> orientation, which is the normal direction of the glass substrate. An X-ray stress measurement method for crystalline thin films with orientation properties such as columnar structure is proposed and applied to the residual stress measurement of AlN thin films with orientation <00·1>. Strength of diffraction lines other than 00·2 diffraction is very weak. As a result of stress measurement using AlN powder sample as a comparative standard sample, tensile residual stress is obtained when the nitrogen gas pressure is low, but the gas pressure increases as the residual stress is shifts toward compression. At low gas pressure, the unit cell expands due to the incorporation of excess nitrogen atoms.

• Journal of Surface Science and Engineering
• /
• v.24 no.4
• /
• pp.196-205
• /
• 1991

Multi-level thin films are very important in ULSI applications because of their high electromigration resistance. This study presents the effects of titanium, titanium nitride and titanium tungsten underlayers of the stability of multi-aluminum thin films during isothermal annealing. High purity Al(99.999%) films have been electron-beam evaporated on Ti, TiN, TiW films formed on SiO2/Si (P-type(100))-wafer substrates by RF-sputtering in Ar gas ambient. The hillock growth was increased with annealing temperatures. Growth of hillocks was observed during isothermal annealing of the thin films by scanning electron microscopy. The hillock growth was believed to appear due to the recrystallization process driven by stress relaxation during isothermal annealing. Thermomigration damage was also presented in thin films by grain boundary grooving processes. It is shown that underlayers of Al/TiN/SiO2, Al/TiW/SiO2 thin films are preferrable to Al/SiO2 thin film metallization.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.303-304
• /
• 2008

Al, N-codoped ZnO(ZnO:N,Al) thin films were deposited on n-type Si(100) substrate at $450^{\circ}C$ with various conditions of ambient gas$(N_2:O_2)$ by DC magnetron sputtering method using ZnO:$Al_2O_3$(2wt%) as a target, and then were annealed at 500, 700, $800^{\circ}C$ in $N_2$ gas for one hour. XRD patterns showed that all of the ZnO:N,Al thin films annealed at $80^{\circ}C$ grew with two peaks, which means poor crystallinity of the thin films deposited. Hall effects in Van der Pauw configuration proved that after annealing the films deposited showed low resistivity and high carrier concentration. While the films annealed at $800^{\circ}C$ showed low resistivity of $\sim10^{-2}\Omega$ cm and high carrier concentration of $\sim10^{19}cm^{-3}$.

• Proceedings of the KIEE Conference
• /
• 2002.07c
• /
• pp.1479-1481
• /
• 2002

AlN thin films were deposited on Si(100) and $SiO_2$/Si substrates using R.F. magnetron sputtering system. The effect of various deposition conditions on the crystal orientation of AlN films was investigated to obtain a highly (002)-oriented films. SAW filters were fabricated using AlN films with various thicknesses and their frequency response characterizations were measured. Experimental results showed that the (002)-orientation and surface roughness of AlN films played a crucial role of determining the frequency response of AlN SAW devices.