( 5%) [2] AlN 6.2 ev [3] AlN 1 22 GPa [4] TiN/AlN 30 GPa [5] AlN [6 7] AlN SAW [8] AlN N 2 AlN N 2 AlN Si(100) AlN Ar N 2 N 2 AlN AlN AlN A

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1 Vol.19 No.1 Materials Science and Engineering of Powder Metallurgy Feb AlN 1 1 1, (1., ; ) Ar N 2 (Ar N 2 ) N 2 ( )φ(n 2 ) (100) AlN X (XRD) (SEM) (AFM) φ(n 2 ) AlN φ(n 2 ) φ(n 2 ) AlN (002) φ(n 2 ) AlN AlN 12.0~29.3 GPa 184.0~209.8 GPa O484 A (2014) Effect of nitrogen concentration on microstructure and mechanical properties of reactive radio frequency magnetron sputtered AlN thin films YU Zhi-ming 1, LIU Dan-ying 1, WEI Qiu-ping 1, 2, ZHANG Xiong-wei 1, LONG Fen 1, LUO Jia-qi 1, WANG Yi-jia 1 (1. School of Materials Science and Engineering, Central South University, Changsha , China; 2. State Key laboratory of Powder Metallurgy, Central South University, Changsha , China) Abstract: The wurtzite structural aluminum nitride (AlN) films were deposited on Si(100) wafers by reactive radio frequency (RF) magnetron sputtering system, using a gas mixture of Ar(sputtering gas)and N 2 (reactive gas) with varying nitrogen flow ratio. The properties of aluminum nitride thin films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and nanoindentation techniques. The results show that the preferred orientation, crystallinity, deposition rate and nanomechanical properties significantly depend upon the nitrogen flow ratio. The microstructure and the surface roughness are also influenced by the nitrogen flow ratio. As the nitrogen flow ratio increases, the thickness and deposition rate of the film decrease, and the crystallinity of the films changes obviously. The growing of AlN films along preferred orientation (002) is improved under higher nitrogen flow ratio. The nitrogen concentration has little influence on the elastic modulus but obviously affects the hardness of AlN films. The AlN films fabricated in this study have excellent nano-mechanics properties with hardness in the range of 12.0~29.3 GPa and elastic modulus in the range of 184.0~209.8 GPa. Key words: AlN films; reactive sputtering; preferred orientations; nanoindentation; hardness AlN III V AlN AlN GHz (SAW) (BAW) [1] ( ) (2012M521541) : ; qiupwei@csu.edu.cn

2 ( 5%) [2] AlN 6.2 ev [3] AlN 1 22 GPa [4] TiN/AlN 30 GPa [5] AlN [6 7] AlN SAW [8] AlN N 2 AlN N 2 AlN Si(100) AlN Ar N 2 N 2 AlN AlN AlN AlN 1 CSU550-I AlN 60 mm 4 mm Al % Ar N % Si(100) 10 mm 10 mm 0.5 mm 10 nm 5%( ) HF Pa 200 W 30 mm 0.2 Pa 1 h D08-3B/EM N 2 Ar (1) ( ) N 2 F(N2) ( N 2) 100% (1) F(N ) F(Ar) 2 F(N 2 ) F(Ar) N 2 Ar cm 3 /min 5 F(N 2 ):F(Ar) 3:7 4:6 5:5 6:4 12:3 N 2 φ(n 2 ) 30% 40% 50% 60% 80% 30~150 Dmax-2500VBX X (XRD) Cu Kα = nm Si(400) 20 ~68 SOLVER P47 (AFM) Quanta200 Environmental (SEM) CSM UNHT 3~5 10% 0.46~2 mn AlN SEM 1 φ(n 2 ) 30% 40% 50% 60% AlN μm nm/min N 2 AlN φ(n 2 ) φ(ar) N 2 [9 10] φ(n 2 ) AlN AlN 2. 2 AlN 2 AlN XRD 2 φ

3 19 1 AlN N 2 AlN SEM Fig.1 The cross-sectional SEM images of AlN thin films deposited at various volume fraction of nitrogen (a) 30%; (b) 40%; (c) 50%; (d) 60% 2 φ(n 2 ) AlN XRD Fig.2 XRD patterns of AlN thin films deposited at various nitrogen volume fraction (N 2 ) 30% AlN (100) (002) (102) (103) φ(n 2 ) 40% AlN (100) φ(n 2 ) 50%~80% AlN c φ(n 2 ) 2 4 XRD SiO 2 (110) φ(n 2 ) AlN 2 Al N B 1 B 2 B 2 B 1 AlN (100) B 1 (002) (101) (102) (103) B 1 B 2 [11] B 2 (002) (103)

4 B 2 φ(n 2 ) B 2 φ(n 2 ) Ar 1 2 B 2 [12] φ(n 2 ) 30% Al B 2 (002) (103) (002) (103) φ(n 2 ) 40% N Al N, Al N AlN φ(n 2 ) Al (100) φ(n 2 ) 50%~80% B 2 N Al (002) AlN [13] 2.4 AlN 5 φ(n 2 ) AlN 28~80 nm 52 nm 80 nm 1 mn 2 mn 40 nm 0.46~0.62 mn 6 φ(n 2 ) 30% 24.0~40.0 GPa 169.0~240.8 GPa φ(n 2 ) 40% 50% φ(n 2 ) 30% 11.0 ~13.0 GPa w 163.1~205.6 GPa Sheng-Rui Jian [4, 16] Feby Jose [17] ( 20~40 nm) φ(n 2 ) 30% 60% shallow indentation ( 40 nm ) φ(n 2 ) AlN φ(n 2 ) AlN 12.0~29.3 GPa 184.0~209.8 GPa AlN (AFM) Figueroa U [18] AlN AlN 4 AlN φ(n 2 ) φ(n 2 ) 30%~40% 50%~80% φ(n 2 ) φ(n 2 ) 40% 50% φ(n 2 ) 30%~80% AlN z (R max ) 24.5~44.5 nm (RMS) 4.1~5.6 nm 30 nm [14] φ(n 2 ) 50% AlN 2 [15] Al N Medjani F [19] N 2 AlN Jian Sheng-rui [20] (103) AlN 17.6~37.5 nm Hall-Petch XRD SEM AFM φ(n 2 ) AlN

5 19 1 AlN φ(n 2 ) AlN (AFM) Fig.3 Surface AFM (atomic force microscope)images of AlN films deposited at various φ(n 2 ) (a) 30%; (b) 40%; (c) 50%; (d) 60%; (e) 80%

6 AlN 3 4 AlN φ(n 2 ) Fig.4 Effect of N 2 flow ratios on film surface roughness ( RMS and R max are denoted as the root mean square values of the surface roughness and the highest peak value in the z-axis, respectively) 1) AlN N 2 φ(n 2 ) AlN φ(n 2 ) AlN (002) φ(n 2 ) 50% AlN c AlN 2) φ(n 2 ) φ(n 2 ) AlN 4.1~5.6 nm 3) φ(n 2 ) AlN AlN 12.0~29.3 GPa 184.0~209.8 GPa REFERENCES [1] RODRIGUEZ-MADRID J G, IRIARTE G F, PEDROS J, et al. Super-high-frequency SAW resonators on AlN/Diamond [J]. Electron Device Letters, IEEE, 2012, 33(4): [2] DETTMER E S, ROMENESKO B M, CHARLES JR H K, et al. Steady-state thermal conductivity measurements of AlN and SiC substrate materials [J]. Components, Hybrids, and Manufacturing Technology, IEEE Transactions on, 1989, 12(4): [3] STRITE S, MORKOC H. GaN, AlN, and InN: A review [J]. Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1992, 10(4): [4] JIAN S R, CHEN G J, LIN T C. Berkovich nanoindentation on AlN Thin Films [J]. Nanoscale Research Letters, 2010, 5(6): [5] OLIVEIRA I C, GRIGOROV K G, MACIEL H S, et al. High textured AlN thin films grown by RF magnetron sputtering; composition, structure, morphology and hardness [J]. Vacuum, 2004, 75(4): [6] KUANG Xu-ping, ZHANG Hua-yu, WANG Gui-gen, et al. AlN 5 AlN (a) (b) Fig.5 Indentation depth against measured hardness (a) and elastic modulus (b) of AlN films as function of nitrogen flow ratio films prepared on 6H SiC substrates under various sputtering pressures by RF reactive magnetron sputtering [J]. Applied Surface Science, 2012, 263: [7] LIU H Y, TANG G S ZENG F, et al. Influence of sputtering parameters on structures and residual stress of AlN films

7 19 1 AlN 107 deposited by DC reactive magnetron sputtering at room temperature [J]. Journal of Crystal Growth, 2013, 363: [8],,,. (100) AlN [J]., 2012, 23(7): YIN Tao-tao, YANG Bao-he, LI Cui-ping, et al. Preparation and piezoelectric properties of (100) oriented AlN film [J]. Journal of Optoelectronics Laser, 2012, 23(7): [9] PENZA M, de RICCARDIS M F, MIRENGHI L, et al. Low temperature growth of R.F. reactively planar magnetronsputtered AlN films [J]. Thin Solid Films, 1995, 259(2): [10] ABABNEH A, SCHMID U, HERNANDO J, et al. The influence of sputter deposition parameters on piezoelectric and mechanical properties of AlN thin films [J]. Materials Science and Engineering: B, 2010, 172(3): [11] XU X H, WU H S, ZHANG C J, et al. Morphological properties of AlN piezoelectric thin films deposited by DC reactive magnetron sputtering [J]. Thin Solid Films, 2001, 388(1/2): [12] CHENG H, SUN Y, ZHANG J X, et al. AlN films deposited under various nitrogen concentrations by RF reactive sputtering [J]. Journal of Crystal Growth, 2003, 254(1/2): [13] KUSAKA K, TANIGUCHI D, HANABUSA T, et al. Effect of sputtering gas pressure and nitrogen concentration on crystal orientation and residual stress in sputtered AlN films [J]. Vacuum, 2002, 66(3/4): [14],,,. [M]. :, 1984: XU Chang-Kun MENG Xiu-Lin LIN Jiang et al. Acoustic Surface Wave Apparatus and its Application [M]. Beijing: Science Press, 1984: [15],,,. [J]., 2000, 29(6): XU Xiao-hong, WU Hai-shun, ZHANG Fu-qiang, et al. Studies of the structure and surface roughness of AlN thin films [J]. Rare Metal Materials and Engineering, 2000, 29(6): [16] JIAN S R, JUANG J Y. Indentation-induced mechanical deformation behaviors of AlN thin films deposited on c-plane sapphire [J]. Journal of Nanomaterials, 2012, 2012(36): 1 6. [17] JOSE F, RAMASESHAN R, TRIPURA SUNDARI S, et al. Nanomechanical and optical properties of highly a-axis oriented AlN films [J]. Applied Physics Letters, 2012, 101(25): [18] FIGUEROA U, SALAS O, OSEGUERA J. Processmicrostructure-properties relationship during formation of AlN layers by physical vapour deposition [J]. Surface Engineering, 2006, 22(2): [19] MEDJANI F, SANJIN S R, ALLIDI G, et al. Effect of substrate temperature and bias voltage on the crystallite orientation in RF magnetron sputtered AlN thin films [J]. Thin Solid Films, 2006, 515(1): [20] JIAN S R, CHEN G J, JANG J S C, et al. Nanomechanical properties of AlN(103) thin films by nanoindentation [J]. Journal of Alloys and Compounds, 2010, 494(1/2): ( )