Effects of the annealing heating rate on sputtered aluminum oxide films

Abstract

Al _xO _y films by DC reactive magnetron sputtering were annealed in air ambient at 500 °C for 1 h with different heating rates of 5, 15, and 25 °C/min.Then heat treatments at 900 °Cwere carried out on these 500 °C-annealed films to simulate the high-temperature application environment. Effects of the annealing heating rate on structure and properties of both 500 °C-annealed and 900 °C-heated films were investigated systematically.It was found that distinct γ-Al₂O₃ crystallization was observed in the 900 °C-heated films only when the annealing heating rates are 15 and 25 °C/min. The 500 °C-annealed film possessed the most compact surface morphology in the case of 25 °C/min. The highest microhardness of both 500 °C-annealed and 900 °C-heated films were obtained when the annealing heating rate was 15 °C/min.

Keywords

aluminum oxide film / sputtering / annealing heating rate / microstructure

References

[1] Rother B. Alumina Coatings Deposited with Reactive DC Magnetron Sputtering in a CO₂/O₂ Gas Mixture[J]. Surf. Coat. Technol., 2002, 154: 262-267.

[2] Cremer R, Reichert K, Neuschütz D, et al. Sputter Deposition of Crystalline Alumina Coatings.[J]. Surf.Coat.Technol., 2003, 163: 157-163.

[3] Kyrylov O, Cremer R, Neuschütz D. Deposition of Alumina Hard Coatings by Bipolar Pulsed PECVD[J]. Surf. Coat. Technol., 2003, 163: 203-207.

[4] Georg Erkens. New Approaches to Plasma Enhanced Sputtering of Advanced Hard Coatings[J]. Surf. Coat. Technol., 2007, 201: 4806-4812.

[5] Edlou S M, Smajkiewicz A, Al-Jumaily G A. Optical Properties and Environmental Stability of Oxide Coatings Deposited by Reactive Sputtering[J]. Appl. Optics, 1993, 32(28): 5601-5605.

[6] Schneider J M, Sproul W D, Voevodin A A, et al. Crystalline Alumina Deposited at Low Temperatures by Ionized Magnetron Sputtering[J]. J. Vac.Sci. Technol.A, Vac. Surf. Films, 1997, 15(3): 1084-1088.

[7] Zhu S, Wang F, Lou H, et al. Reactive Sputter Deposition of Alumina Films on Superalloys and Their Hightemperature Corrosion Resistance[J]. Surf. Coat. Technol., 1995, 71: 9-15.

[8] Li Y, Xie Y, Huang L, et al. Effect of Physical Vapor Deposited Al₂O₃ Film on TGO Grow Thin YSZ/CoNiCrAlY Coatings[J]. Ceramics International, 2012, 38: 5113-5121.

[9] Zhao H, Peng X, Feng Q, et al. Effect of a Thin Al₂O₃ Film on High Temperature Oxidation of a Sm(Co_0.68Fe_0.22Cu_0.08Zr_0.02)_7.5 Alloy[J]. Corrosion Science, 2014, 88: 133-140.

[10] Cremer R, Witthaut M, Reichert K, et al. Thermal Stability of Al-O-N PVD Diffusion Barriers[J]. Surf. Coat. Technol., 1998, 108–109: 48-58.

[11] Hirvikorpi T. Thin Al ₂ O ₃ Barrier Coatings Grown on Bio-based Packaging Materials by Atomic Layer Deposition[D], 2011 Finland: Aalto University.

[12] Kamran A, Kyung-Hyun C, Jeongdai J, et al. High Rate Rollto-roll Atmospheric Atomic Layer Deposition of Al₂O₃ Thin Films towards Gas Diffusion Barriers on Polymers[J]. Materials Letters, 2014, 136: 90-94.

[13] Atul K, Deepak G B, Adrian H, et al. Structure-property Correlations in Aluminum Oxide Thin Films Grown by Reactive AC Magnetron Sputtering[J]. Surf. Coat.Technol., 2006, 201: 1109-1116.

[14] Edlmayr V, Moser M, Walter C, et al. Thermal Stability of Sputtered Al₂O₃ Coatings[J]. Surf. Coat.Technol., 2010, 204: 1576-1581.

[15] Atul K, Deepak G Bhat. Nanocrystalline Gamma Alumina Coatings by Inverted Cylindrical Magnetron Sputtering[J]. Surf. Coat. Technol., 2006, 201: 168-173.

[16] Musil J, Blazek J, Zeman P, et al. Thermal Stability of Alumina Thin Films Containing γ-Al₂O₃ Phase Prepared by Reactive Magnetron Sputtering[J]. Appl. Surf. Sci., 2010, 257: 1058-1062.

[17] Per E, Madanagurusamy S, Gurvinder S, et al. Thermal Stability and Phase Transformations of γ-/Amorphous-Al₂O₃ Thin Films[J]. Plasma Process, Polym., 2009 6

[18] Hu H, Peng C J, Krupanidhi S B. Effect of Heating Rate on the Crystallization Behavior of Amorphous PZT Thin Films[J]. Thin Solid Films, 1993, 223: 327-333.

[19] Rhee S-H, Lee J D, Kim D-Yeon. Effect of Heating Rate on the Exaggerated Grain Growth Behavior of β-Si₃N₄[J]. Materials Letters, 1997, 32: 115-120.

[20] Robert R O, Paul H H, Gregory J E, et al. Effect of Annealing and Lithium Substitution on Conductivity in Nickelcobalt Oxide Spinel Films[J]. Surf. Interface Anal., 2005, 37: 424-431.

[21] Tang X, Luo F, Ou F, et al. Effects of Negative Substrate Bias Voltage on the Structure and Properties of Aluminum Oxide Films Prepared by DC Reactive Magnetron Sputtering[J]. Applied Surface Science, 2012, 259: 448-453.

[22] Olsson M K, Macak K, Helmersson U, et al. High Rate Reactive DC Magnetron Sputter Deposition of Al₂O₃ Films[J]. J. Vac. Sci. Technol., 1998, A16(2): 639-643.

[23] Olsson M K, Macák K, Graf W. Reactive DC Magnetron Sputter Deposited Al₂O₃ Films: Large-area Coatings for Industrial Applications[J]. Surf. Coat.Technol., 1999, 122: 202-207.

[24] Lu K. Nanocrystalline Metals Crystallized from Amorphous Solids: Nanocrystallization, Structure, and Properties[J]. Mater. Sci. Eng. R, 1996, 16: 161-121.

[25] Messier R, Kakamori T, Roy R. Structural Differences among Different Non-crystalline Ge-Te Phases[J]. J. Non-Cryst. Solids, 1972, 8–10: 816-822.

[26] Krishnaswamy S V, Messier R, Swab P, et al. Explosive Crystallization of Rf-Sputtered Amorphous CdTe Films[J]. Journal of Electronic Materials, 1981, 10(3): 433-443.