W. PHAE-NGAM et al.: EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS ... 65–70 EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS GROWN BY REACTIVE MAGNETRON CO-SPUTTERING WITH THE OAD TECHNIQUE VPLIV ^ASA NANA[ANJA NANOSTEBRI^ASTIH TiZrN FILMOV Z OAD TEHNIKO IN HKRATNIM REAKTIVNIM MAGNETRONSKIM NAPR[EVANJEM Wuttichai Phae-ngam 1* , Chanunthorn Chananonnawathorn 2 , Tossaporn Lertvanithphol 2 , Benjarong Samransuksamer 2 , Mati Horprathum 2 , Teeranon Chaiyakun 3 1 Physics Program, Phranakhon Rajabhat University, Bangkok 10220, Thailand 2 National Electronics and Computer Technology Center, Pathumthani 12120, Thailand 3 Industrial Electrical Technology Program, Faculty of Industrial Technology, Valaya Alongkorn Rajabhat University under the Royal Patronage, Pathumthani 13180, Thailand Prejem rokopisa – received: 2019-08-17; sprejem za objavo – accepted for publication: 2020-09-24 doi:10.17222/mit.2019.189 Well-separated inclined nanocolumnar TiZrN films were grown on silicon-wafer substrates by reactive magnetron co-sputtering with the oblique-angle-deposition (OAD) technique. The crystal structure, thickness, morphology and chemical composition of the prepared TiZrN films were investigated with the X-ray diffraction technique at the grazing-incidence angle (GIXRD), field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). The length, diameter and tilt angle of the nanocolumnar TiZrN films were evaluated. The microstructure and chemical composition were analyzed with transmission electron microscopy (TEM). The results indicated that the film crystallinity and physical morphology were in- fluenced by the deposition time due to the self-annealing effect, which occurred during the nanocolumnar growth. Moreover, the hardness and surface wettability of the TiZrN films were studied using a nanoindentater and the water-contact-angle method, re- spectively. It was found that the hardness and hydrophobic surface of the TiZrN films decreased with the increasing deposition time. Keywords: TiZrN film, OAD, reactive co-sputtering, self-annealing effect Avtorji v ~lanku opisujejo rast dobro medsebojno lo~enih in nagnjenih nanostebri~astih TiZrN filmov na silicijevih rezinah med postopkom isto~asnega reaktivnega magnetronskega napr{evanja s tehniko po{evno kotnega nanosa oz. depozicije (OAD, angl.: oblique angle deposition). Kristalno strukturo izdelanih TiZrN filmov, njihovo debelino in morfologijo so analizirali z rentgensko difrakcijo (XRD), rentgensko tehniko GIXRD (angl.: grazing-incidence angle X-ray diffraction), vrsti~nim elektronskim mikroskopom (FE-SEM) in spektroskopijo na osnovi energijske disperzije rentgenskih `arkov (EDS). Avtorji so ocenili dol`ino, premer in nagib nanostebri~kov izdelanih tankih plasti (filmov) na osnovi TiZrN. Njihovo mikrostrukturo in kemijsko sestavo so analizirali s presevnim elektronskim mikroskopom (TEM). Rezultati analiz ka`ejo, da so izdelani filmi kristalini~ni in njihova morfologija je odvisna od ~asa napr{evanja zaradi u~inka samomeh~anja, ki poteka med rastjo nanostebri~kov. Nadalje so avtorji dolo~ali trdoto in omakanjem povr{ine TiZrN filmov z metodama nanoindentacije in metodo merjenja kota omakanja. Na osnovi izvedenih analiz avtorji ugotavljajo, da se trdota in hidrofobnost povr{ine TiZrN filmov zmanj{uje s podalj{evanjem ~asa napr{evanja. Klju~ne besede: TiZrN film, OAD, reaktivno isto~asno napr{evanje, u~inek samo-popu{~anja (samo-meh~anja) 1 INTRODUCTION Recently, nanostructured materials have attracted considerable attention due to their unique properties and potentials in various applications such as nanoelectronics and nanophotonic devices. Nanostructured materials have been synthesized with numerous techniques, i.e., vapor-liquid-solid deposition, 1–3 chemical vapor depo- sition 4–6 and physical vapor deposition. 7–11 Physical vapor deposition (PVD) carried out with the oblique angle de- position (OAD) technique is a suitable method for pre- paring one-dimensional nanostructures as well as nano- columnar ones where the orientation of an isolated nanocolumnar growth can be controlled with the self-shadowing effect and limited adatom diffusion. 12–14 Considering these PVD methods, the magnetron sputter- ing has been used as a promising technique as it allows an easy adjustment of deposition parameters and it is ap- plicable at laboratory and industrial scales. Moreover, several materials, for example, metal, metal oxide/nitride can be prepared to provide for a nanocolumnar film with a well-controlled structure and film crystallinity realized by magnetron sputtering with the OAD technique. Re- cently, the OAD technique has been developed for bime- tallic alloys and ternary oxides/nitrides realized by mag- netron sputtering with an alloy target. 15,16 A sputtering target requires a specially prepared alloy, or powder tar- get, and the composition of the film depends on the ele- ments in the target. Magnetron co-sputtering is a promis- Materiali in tehnologije / Materials and technology 55 (2021) 1, 65–70 65 UDK 620.3:621.793.7:620.1 ISSN 1580-2949 Original scientific article/Izvirni znanstveni ~lanek MTAEC9, 55(1)65(2021) *Corresponding author's e-mail: wuttichai@pnru.ac.th (Wuttichai Phae-ngam) ing method, which can help us control the composition of the films. Only few works reported on magnetron co-sputtering at an oblique angle used for preparing a nanostructure bimetallic alloy. 17,18 Nevertheless, the prep- aration of a ternary metal nitride with reactive magnetron co-sputtering using the OAD technique was successful and reported by our group. 19 Significant findings were reported including the effects of the crucial deposition conditions such as the sputtering power, structure and morphology of nanocolumnar films. In this work, we focus on titanium zirconium nitride (TiZrN) because this ternary metal nitride has gained much attention as due to its superior mechanical proper- ties, including better corrosion resistance, good tough- ness, low electrical resistivity, biocompatibility and high thermal stability. Moreover, a systematic research of the nanoscale property of the nanocolumnar TiZrN films provided a significant and meaningful contribution to the development of novel advanced applications in the fu- ture. Thus, in this present study, the effects of the deposi- tion time on the film thickness, crystallinity, morphol- ogy, composition, surface wettability and hardness of the nanocolumnar TiZrN films prepared by reactive magne- tron co-sputtering with the OAD technique were pre- sented and discussed. 2 EXPERIMENTAL PART Figure 1a shows a schematic of the reactive magne- tron co-sputtering set-up using the OAD technique. Me- tallic titanium (Ti with a 99.99 % purity) and zirconium (Zr with a 96.9 % purity) with a diameter of 2 inches were used as the sputtering targets. The substrate was a Si wafer (100) and it was placed at an oblique angle with respect to the direction normal to the target. The targets were focused on the center of the substrate (d Ti-sub =50 mm and d Zr-sub = 50 mm) in a confocal configuration, making fixed angles of 88° ( 1 ) and 85°( 2 ) for the Ti target and Zr target, respectively, with respect to the plane of the substrate holder. The deposition flux ap- proached the stationary substrate at an oblique angle ( ) relative to the substrate normal, referred to the incident angle, producing well-isolated nanocolumnar films due to the self-shadowing effect and limited adatom diffusion as shown in Figure 1b. Prior to the installation of the silicon-wafer substrates in the vacuum chamber, they were cleaned with an ultra- sonic cleaner in acetone, isopropanol and then with DI water. The base pressure of the deposition chamber was about3×10 –6 Torr. The operating pressure was 5 mTorr, controlled by a pressure gauge, whereas mass-flow con- trollers regulated the high-purity argon (Ar with a 99.999 % purity) and nitrogen (N 2 with a 99.999 % purity) with flow rates of 15 sccm and 20 sccm, respectively. The DC sputtering powers applied to the Ti and Zr targets were kept constant at 225 W and 250 W, respectively. The de- position chamber was evacuated by a rotary pump (ALCATEL) and turbo-molecular pump (Shimazu, TMP-803-LM). Prior to the deposition, in-situ plasma cleaning with Ar plasma ions was performed at a pres- sure of 10 mTorr for 15 min and a substrate bias of –150 V in order to remove any residue from the Si substrate surfaces. The experiment was carried out with different deposition times of (60, 120, 180 and 240) min. The crystal structure of the films was characterized with X-ray diffraction at the grazing-incidence angle (GIXRD; RigakuTtraz III), with the Cu K radiation op- erating at 50 kV, 300 mA. The measurements were re- corded in a 2 range of 20–70° with a scanning speed of 2° per min and a 2 step of 0.02°. The film thickness and morphology were observed with field-emission scanning electron microscopy (FE-SEM; Hitachi, S8080) at an op- erating voltage of 10 kV. The microstructure of the TiZrN films was analyzed with high-resolution transmission electron microscopy (HRTEM; JEOL JEM-2010) performed at an accelerat- ing voltage of 200 kV. The TiZrN films prepared on Si were scrapped off the Si substrate surface with a dia- mond cutter and nanorod powders of the TiZrN films were obtained. The powders were dispersed in ethanol and dropped onto carbon-coated copper grids for a microstructure analysis with TEM. When observing a W. PHAE-NGAM et al.: EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS ... 66 Materiali in tehnologije / Materials and technology 55 (2021) 1, 65–70 Figure 1: a) Schematic of the reactive magnetron co-sputtering set-up using the OAD technique; b) diagram showing the growth of nano- columnar TiZrN films nanorod image, we tried to find an area with only one rod in the field of view. The hardness of the TiZrN films prepared on the sili- con-wafer substrate was investigated with a nanoindenter (CSM Instrument, NHT 2 ) with a diamond Berkovich- type head and the applied load was in a range of 0.6–1.2 mN. A suitable load of indentation was selected based on the indent depth, which should be equal to 10 % of the total film thickness to avoid the influence of the substrate on the film layer. The loading and unload- ing were chosen to be linearly increasing and decreasing with a time of 30 s for both. The hardness was calculated using the Oliver-Pharr method. 20,21 The surface wett- ability behavior of the films was examined at a water contact angle (Ramé-Hart Instrument, Model 250) in am- bient air (25 °C, a relative humidity of 50 %). 3 RESULTS AND DISCUSSION Figure 2 shows the GIXRD patterns of the TiZrN films prepared at different deposition times of (60, 120, 180 and 240) min. Two major peaks corresponding to the (111) and (200) planes of the NaCl-type crystalline structure were observed. It is clearly seen that the reflec- tion of TiZrN peaks appeared between TiN (JCPDS: no. 35-0753) and ZrN (JCPDS: no. 38-1420). The result in- dicates that the TiZrN films prepared at 60 min and 120 min show a broad reflection of the (111) peak. When the deposition time was increased to 240 min, the peaks be- came more intense and sharper. A longer deposition time results in a localized heating treatment of the substrate surface and enhancement of the film crystallinity. 9 Figure 3 shows top-view and cross-section FE-SEM images of the TiZrN films deposited at different deposi- tion times. It can be clearly observed that all the prepared films exhibit a porous and well-separated, inclined nanocolumnar growth. The top-view FE-SEM images show more porosity with large spaces between nanocolumnar growths as the deposition time increases. The cross-section FE-SEM images reveal the evolution of an inclined nanocolumnar growth, whose thickness (d), length and incline angle ( ) increase as a result of the enhancement of the shadowing effect during the film growth achieved with the OAD technique. Generally, the inclined nanocolumnar growth process might be divided into two stages as shown in Figure 3b. In the early stage, the cluster of atoms were randomly deposited on the substrate, forming the initial nucleation site. Since the next atom cluster from the vapor flux at the oblique angle could not reach the shadow areas of the initial cluster atom, the adatoms accumulated only on the taller island. This preferential growth dynamic allowed W. PHAE-NGAM et al.: EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS ... Materiali in tehnologije / Materials and technology 55 (2021) 1, 65–70 67 Figure 3: Top-view and cross-section FE-SEM images of TiZrN films deposited at (60, 120, 180 and 240) min Figure 2: GIXRD patterns of the TiZrN films prepared at different de- position times the formation of a nanocolumnar structure tilted to the incoming-flux direction. 7–10 Furthermore, the thickness (d) and length of a nanocolumn were influences by the deposition time. The diameter of a nanocolumn was con- trolled by the atomic mobility of the material, which was affected by the material property and deposition condi- tion as well as the temperature during the film deposi- tion. 9 Note that the nanocolumn tilt angle was affected by the deposition angle and surface mobility of the adatoms on the surface of the substrate. In order to make good measurements of the obtained nanocolumnar TiZrN films, the thickness, diameter, length and nanocolumnar tilt angle ( ) at different depo- sition times were evaluated and plots of these values as a function of deposition time are shown in Figure 4. It is seen that the thickness and length increase lin- early with the increase in the deposition time. The diam- eter of the nanocolumnar growth was also found to in- crease with the increasing deposition time. With the increasing thickness and length of the nanocolumnar growth, the number of the nanocolumns per unit area was reduced significantly as the deposition time in- creased (as seen in Figure 3), which was the result of some nanocolumnar growth entering the shadow area of the adjacent nanocolumn that could not grow up, and the area of the remaining nanocolumn exposed to the incom- ing adatom flux was increased with the increasing length. Furthermore, the nanocolumnar growth became large regarding its diameter as a result of the self-anneal- ing effect. The increase in the deposition time led to a merged nanocolumnar growth, with a diameter varying in a range of 40–87 nm. This could be attributed to the surface-diffusion effect where a longer deposition time eventually caused an increase in the ambient temperature that enhanced the adatom mobility 9,22 . Moreover, the nanocolumnar growth of the TiZrN films tend to bend with the increasing film thickness. The tilt angle ( )of the nanocolumn growth with respect to the silicon sub- strate was increased from 35° to 42° which is slightly lower than the theoretical value ( = 57.84-59.15 for = 85–88° as predicted by the cosine rule (2sin( )=1– cos )). However, the difference between the theoretical and experimental result values may have been caused by all the adatoms produced by co-sputtering that did not have the same direction so that the column angle from the experimental data is lower than that from the calcula- tion data. There is variation in the deposition parameters, i.e., the operating pressure, substrate temperature and preferred crystallinity of the deposited material 23 .Inad- dition, the results of the EDS element analysis (not shown here) confirmed that the nanocolumnar TiZrN films contain Ti, Zr and N with the averaged contents of 27.0, 24.7 and 48.3 at.% respectively, at all deposi- tion times. Figure 5 shows bright-field TEM images of individ- ual nanocolumnar TiZrN films prepared at 60 and 240 min. All the nanocolumnar films exhibit high porosity, which many nanoridge structures present along a colum- nar surface. The formation of a nanoridge structure grown with OAD was also observed in the literature. 10 Moreover, the nanocolumnar TiZrN films deposited at 60 min are clearly observed to have a diameter of 55 nm and length of 320 nm. The TEM image of the film de- posited at 240 min shows a 96 nm diameter and 1105 nm length, which are in good agreement with the FE-SEM results. Further analysis of the crystallinity of the nanocolumnar film from the selective-area elec- tron-diffraction pattern (SAED) shows a polycrystalline structure mixed with an amorphous structure after the W. PHAE-NGAM et al.: EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS ... 68 Materiali in tehnologije / Materials and technology 55 (2021) 1, 65–70 Figure 4: a) Thickness, b) length, c) diameter and d) tilt angle ( )of the nanocolumnar TiZrN films deposited at different deposition times Figure 5: Bright-field TEM images and SAED patterns of the nanocolumnar TiZrN films prepared at: a) 60 and b) 240 min 60-min deposition time. After the 240-min deposition time, the nanocolumnar film was found to be highly crystalline. Therefore, the SAED results are in good agreement with GIXRD. Figure 6 shows the hardness and modulus of the nanocolumnar TiZrN films as a function of deposition times. Note that each reported hardness and modulus value was the average of 5 indentations. One can see that the hardness and modulus diminished with an increase in the deposition time, which was probably the cause of the porosity degree of the nanocolumnar structure, as indi- cated by the FE-SEM result (Figure 3). During the co-sputtering process with a longer deposition time, the substrate is heated by the energy of the particles imping- ing on the film surface and the thermal energy induced by localized substrate heating, hence enhancing the adatom mobility, which leads to the merging of sub-nanocolum and elongated void network. Thus, the overall mass density decreased, which led to a lower hardness and Young’s modulus. 24–26 In addition, the re- sults confirm that our nanocolumnar TiZrN films show a lower hardness value than that of a dense TiZrN film (28–36 Gpa). 27,28 One can suppose that the highly porous structure of the film layer provides a significant contribu- tion to the large decrease in the film density, which re- sulted in a decrease of the hardness. Figure 7 shows the wettability of the nanocolumnar TiZrN films deposited at different deposition times. The wettability was characterized with a water-contact-angle measurement producing photographs of water droplets on the silicon-wafer substrate surfaces. The results indi- cate that all the nanocolumnar films have a hydrophobic surface. The results show that the silicon-wafer substrate, like the reference samples, had a small water-contact an- gle of 43.6°. The water-contact angle for the nano- columnar TiZrN films deposited at 60 min was 91°, which increased to a value of 110° for the nanocolumnar films deposited at 240 min due to the increase in the sur- face roughness. Therefore, the nanocolumnar TiZrN films are expected to perform well in self-cleaning appli- cations. 5 CONCLUSIONS In this study, we successfully deposited nanocolum- nar TiZrN films on silicon-wafer substrates with reactive co-magnetron sputtering using the oblique-angle deposi- tion technique. Longer deposition times clearly indicated higher crystallinity with large diameters of the nanorods due to the self-annealing effect. Moreover, the nano- columnar TiZrN films exhibited low hardness. In addi- tion, the results indicated that the increasing deposition time resulted in an increase in the nanocolumnar tilt an- gle and also in the roughness of the surface, showing super-hydrophobicity. Finally, the present approach al- lowed us to demonstrate a promising technique for pre- paring nanocolumnar ternary films by reactive co-mag- netron sputtering with OAD which is important for future nanodevice applications. Acknowledgment The authors would like to thank the Pharanakorn Rajabhat University for the financial support. 6 REFERENCES 1 A. Klamchuen, M. Suzuki, K. Nagashima, H. Yoshida, M. Kanai, F. Zhuge, Y. He, G. Meng, S. Kai, S. Takeda, T. Kawai, T. Yanagida, Rational concept for designing vapor–liquid–solid growth of single crystalline metal oxide nanowires, Nano Lett., 15 (2015) 10, 6406–6412, doi:10.1021/acs.nanolett.5b01604 2 A. Klamchuen, T. Yanagid, M. Kanai, K. Nagashima, K. Oka, S. Rahong, M. Gang, M. Horprathum, M. Suzuki, Y. Hidaka, S. Kai, T. Kawai, Study on transport pathway in oxide nanowire growth by us- ing spacing-controlled regular array, Appl. Phys. Lett., 99 (2011), 193105, doi:10.1063/1.3660246 3 K. Nagashima, T. Yanagida, K. Oka, M. Kanai, A. Klamchuen, S. Rahong, G. Meng, M. Horprathum, B. Xu, F. Zhuge, Y. He, B. H. Park, T. Kawai, Prominent thermodynamical interaction with sur- roundings on nanoscale memristive switching of metal oxides, Nano Lett., 12 (2012) 11, 5684–5690, doi:10.1021/nl302880a W. PHAE-NGAM et al.: EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS ... Materiali in tehnologije / Materials and technology 55 (2021) 1, 65–70 69 Figure 7: Water contact angle of the Si-substrate surface and the nanocolumnar TiZrN films deposited on Si substrates at various depo- sition times Figure 6: Mechanical properties of the nanocolumnar TiZrN films as a function of the deposition time 4 X. M. Cai, F. Ye, S. Y. Jing, D. P. Zhang, E. Q. Xie, A systematic study of chemical vapor deposition growth of InN, Appl. Surf. Sci., 255 (2008), 2153–2158, doi:10.1016/j.apsusc.2008.07.051 5 K. Teker, Density and morphology adjustments of gallium nitride nanowires, Appl. Surf. Sci., 283 (2013), 1065–1070, doi:10.1016/ j.apsusc.2013.07.069 6 L. Yu, Y. Lv, P. Liu, X. Yu, Synthesis of rhombic and triangular cross-sectional AlN nanorods on Si substrate via thermal CVD, Ma- ter. Lett., 65 (2011) 10, 1499–1502, doi:10.1016/j.matlet.2011. 02.052 7 M. Horprathum, T. Srichaiyaperk, B. Samransuksamer, A. Wisitsoraat, P. Eiamchai, S. Limwichean, C. Chananonnawathron, K. Aiempanakit, N. Nuntawong, V. Patthanasettakul, C. Oros, S. Porntheeraphat, P. Songsiriritthigul, H. Nakajima, A. Tuantranont, P. Chindaudom, Ultrasensitive hydrogen sensor based on Pt-decorated WO3 nanorods prepared by glancing-angle dc magnetron sputtering, ACS Appl. Mater. Interfaces, 6 (2014), 22051–22060, doi:10.1021/ am505127g 8 M. Horprathum, K. Limwichean, A. Wisitsoraat, P. Eiamchai, K. Aiempanakit, P. Limnonthakul, N. Nuntawong, V. Patthanasettakul, A. Tuantranont, P. Chindaudom, NO2- sensing properties of WO3 nanorods prepared by glancing angle DC magnetron sputtering, Sens. Actuators B, 176 (2013), 685–691, doi:10.1016/j.snb.2012. 09.077 9 P. Nuchuaya, T. Chaikeereea, M. Horprathum, N. Mungkung, N. Kasayapanand, C. Oros, S. Limwichean, N. Nuntawong, C. Chananonnawathorn, V. Patthanasettakul, P. Muthitamongkol, B. Samransuksamer, S. Denchitcharoen, A. Klamchuen, C. Thana- chayanont, P. Eiamchai, Engineered omnidirectional antireflection ITO nanorod films with super hydrophobic surface via glancing-an- gle ion-assisted electron-beam evaporation deposition, Curr. Appl. Phys., 17 (2017), 222–229, doi:10.1016/j.cap.2016.11.018 10 C. Oros, M. Horprathum, A. Wisitsoraat, T. Srichaiyaperk, B. Samransuksamer, S. Limwichean, P. Eiamchai, D. Phokharatkul, N. Nuntawong, C. Chananonnawathron, V. Patthanasettakul, A. Klamchuen, J. Kaewkhao, A. Tuantranont, P. Chindaudom, Ultrasensitive NO2 sensor based on vertically aligned SnO2 nanorods deposited by DC reactive magnetron sputtering with glancing angle deposition technique, Sens. Actuators B, 223 (2016), 936–945, doi:10.1016/j.snb.2015.09.104 11 B. Samransuksamer, M. Horprathum, T. Jutarosaga, A. Kopwitthaya, S. Limwichean, N. Nuntawong, C. Chananonnawathorn, V. Patthanasettakul, P. Muthitamongkol, A. Treetong, A. Klamchuen, A. Leelapojanaporn, C. Thanachayanont, P. Eiamchai, Facile method for decorations of Au nanoparticles on TiO2 nanorod arrays toward high-performance recyclable SERS substrates, Sens. Actuators B, 277 (2018), 102–113, doi:10.1016/j.snb.2018.08.136 12 N. Nuntawong, P. Eiamchai, K. Wong-ek, M. Horprathum, K. Limwichean, V. Patthanasettakul, P. Chindaudom, Shelf time effect on SERS effectiveness of silver nanorod prepared by OAD tech- nique, Vacuum, 88 (2013), 23–27, doi:10.1016/j.vacuum.2012. 08.006 13 A. Siad, A. Besnard, C. Nouveau, P. Jacque, Critical angles in DC magnetron glad thin films, Vacuum, 131 (2016), 305–311, doi:10.1016/j.vacuum.2016.07.012 14 A. Barranco, A. Borras, A. R. Gonzalez-Elipe, A. Palmero, Perspec- tives on oblique angle deposition of thin films: From fundamentals to devices, Prog. Mater Sci., 76 (2016), 59–153, doi:10.1016/j.pmatsci. 2015.06.003 15 A. R. Shetty, A. Karimi, M. Cantoni, Effect of deposition angle on the structure and properties of pulsed-DC magnetron sputtered TiAlN thin films, Thin Solid Films, 519 (2011), 4262–4270, doi:10.1016/j.tsf.2011.02.090 16 A. R. Shetty, A. Karimi, Texture mechanisms and microstructure of biaxial thin films grown by oblique angle deposition, Phys. Status Solidi B, 249 (2012) 8, 1531–1540, doi:10.1002/pssb.201248010 17 R. E. Beainou, N. Martin, V. Potin, P. Pedrosa, M. A. P. Yazdi, A. Billard, Correlation between structure and electrical resistivity of W-Cu thin films prepared by GLAD co-sputtering, Surf. Coat., 313 (2017), 1–7, doi:10.1016/j.surfcoat.2017.01.039 18 R. E. Beainou, N. Martin, V. Potin, P. Pedrosa, M. A. P. Yazdi, A. Billard, W-Cu sputtered thin films grown at oblique angles from two sources: Pressure and shielding effects, Surf. Coat. Technol., 343 (2018), 153–159, doi:10.1016/j.surfcoat.2017.09.062 19 W. Phae-ngam, M. Horprathum, C. Chananonnawathorn, T. Ler- tvanithphol, B. Samransuksamer, P. Songsiriritthigul, H. Nakajima, S. Chaiyakun, Oblique angle deposition of nanocolumnar TiZrN films via reactive magnetron co-sputtering technique: The influence of the Zr target powers, Curr. Appl. Phys., 19 (2019), 894–901, doi:10.1016/j.cap.2019.05.002 20 W. C. Oliver, G. M. Pharr, An improved technique for determining hardness and elastic modulus using load and displacement sensing indentation experiments, J. Mater. Res., 7 (1992), 1564–1583, doi:10.1557/JMR.1992.1564 21 W. C. Oliver, G. M. Pharr, Measurement of hardness and elastic modulus by instrumented indentation: Advances in understanding and refinements to methodology, J. Mater. Res., 19 (2004), 3–20 22 C. Patzig, A. Miessler, T. Karabacak, B. Rauschenbach, Arbitrarily shaped Si nanostructures by glancing angle ion beam sputter deposi- tion, Phys. Status Solidi B, 247 (2010), 1310–1321, doi:10.1002/ pssb.200945525 23 P. M. Martin, Handbook of Deposition Technologies for Films and Coatings: Science, Applications and Technology, Chapter 13, Glancing Angle Deposition, 2010, 621–678 24 J. Lintymer, J. Gavoille, N. Martin, J. Takadoum, Glancing angle de- position to modify microstructure and properties of sputter deposited chromium thin films, Surface and Coatings Technology, 174–175 (2003), 316–323, doi:10.1016/S0257-8972(03)00413-4 25 A. R. Shetty, A. Karimi, Texture mechanisms and microstructure of biaxial thin films grown by oblique angle deposition, Phys. Status Solidi B, 249 (2012) 8, doi.10.1002/pssb.201248010 26 A. R. Shetty, A. Karimi, M. Cantoni, Effect of deposition angle on the structure and properties of pulsed-DC magnetron sputtered TiAlN thin films, Thin Solid Films, 519 (2011), 4262–4270, doi:10.1016/j.tsf.2011.02.090 27 Y. W. Lin, H. A. Chen, G. P. Yu, J. H. Huan, Effect of Bias on the Structure and Properties of TiZrN Thin Films Deposited by Unbal- anced Magnetron Sputtering, Thin Solid Films, 618 (2016), 13–20, doi:10.1016/j.tsf.2016.05.021 28 E. W. Niu, L. Li, G. H. Lv, H. Chen, X. Z. Li, X. Z.Yang, S. Z.Yang, Characterization of Ti–Zr–N films deposited by cathodic vacuum arc with different substrate bias, Applied Surface Science, 254 (2008) 13, 3909–3914, doi:10.1016/j.apsusc.2007.12.022 W. PHAE-NGAM et al.: EFFECT OF DEPOSITION TIME ON NANOCOLUMNAR TiZrN FILMS ... 70 Materiali in tehnologije / Materials and technology 55 (2021) 1, 65–70