Effects of sputtering power and annealing temperature on surface roughness of gold films for high-reflectivity synchrotron radiation mirrors
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摘要
Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics.In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers(15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction,and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au(111)orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200 ℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175 ℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.
Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics.In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers(15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction,and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au(111)orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200 ℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175 ℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.
Gold films deposited by direct current magnetron sputtering are used for synchrotron radiation optics.In this study, the microstructure and surface roughness of gold films were investigated for the purpose of developing high-reflectivity mirrors. The deposition process was first optimized. Films were fabricated at different sputtering powers(15, 40, 80, and 120 W) and characterized using grazing incidence X-ray reflectometry, X-ray diffraction,and atomic force microscopy. The results showed that all the films were highly textured, having a dominant Au(111)orientation, and the film deposited at 80 W had the lowest surface roughness. Subsequently, post-deposition annealing from 100 to 200 ℃ in a vacuum was performed on the films deposited at 80 W to investigate the effect of annealing on the microstructure and surface roughness of the films. The grain size, surface roughness, and their relationship were investigated as a function of annealing temperature. AFM and XRD results revealed that at annealing temperatures of 175 ℃ and below, microstructural change of the films was mainly manifested by the elimination of voids. At annealing temperatures higher than 175 ℃, grain coalescence occurred in addition to the void elimination, causing the surface roughness to increase.
引文
1.K.B.Becker,Synchrotron radiation mirrors for high intensity beam lines.Rev.Sci.Instrum.63,1420-1423(1992).https://doi.org/10.1063/1.1143032
2.V.Rehn,V.O.Jones,Vacuum ultraviolet(VUV)and soft X-ray mirrors for synchrotron radiation.Opt.Eng.(1978).https://doi.org/10.1117/12.7972270
3.S.Sugita,A.Furuzawa,K.Ishibashi et al.,Measurement of reflectivity of x-ray mirror for soft x-ray telescope onboard ASTRO-H.Proc.SPIE(2012).https://doi.org/10.1117/12.926711
4.K.Raiber,A.Terfort,C.Benndorf et al.,Removal of selfassembled single layers of alkanethiolates on gold by plasma cleaning.Surf.Sci.595,56-63(2005).https://doi.org/10.1016/j.susc.2005.07.038
5.A.Toyoshima,T.Kikuchi,H.Tanaka et al.,In situ removal of carbon contamination from a chromium-coated mirror:ideal optics to suppress higher-order harmonics in the carbon K-edge region.J.Synchrotron Radiat.22,1359-1363(2015).https://doi.org/10.1107/S1600577515015040
6.F.Tian,X.Li,Y.Wang et al.,Small angle X-ray scattering beamline at SSRF.Nucl.Sci.Tech.26,030101(2015).https://doi.org/10.13538/j.1001-8042/nst.26.030101
7.G.U.Kulkarni,Optimizing growth conditions for electroless deposition of Au films on Si(111)substrates.Bull.Mater.Sci.29,505-511(2006).https://doi.org/10.1007/BF02914082
8.K.Gall,N.West,K.Spark et al.,Creep of thin film Au on bimaterial Au/Si microcantilevers.Acta Mater.52(8),2133-2146(2004).https://doi.org/10.1016/j.actamat.2004.01.005
9.C.K.Malek,B.Kebabi,A.Charai et al.,Effect of thermal treatment on the mechanical and structural properties of gold thin films.J.Vac.Sci.Technol.B(USA)9,3329-3332(1991).https://doi.org/10.1116/1.585336
10.B.Sˇ.Baticˇ,T.Verbovsˇek,J.Sˇetina,Decomposition of thin Au films on flat and structured Si substrate by annealing.Vacuum138,134-138(2017).https://doi.org/10.1016/j.vacuum.2016.12.006
11.X.Zhang,X.Song,D.Zhang,Thickness dependence of grain size and surface roughness for dc magnetron sputtered Au films.Chin.Phys.B 19,086802(2010).https://doi.org/10.1088/1674-1056/19/8/086802
12.W.Tang,K.Xu,P.Wang et al.,Residual stress and crystal orientation in magnetron sputtering Au films.Mater.Lett.57,3101-3106(2003).https://doi.org/10.1016/s0167-577x(03)00004-1
13.J.Wang,B.Zhang,Y.H.Xu et al.,Research on deposition rate of TiZrV/Pd film by DC magnetron sputtering method.Nucl.Sci.Tech.28,50(2017).https://doi.org/10.1007/s41365-017-0199-6
14.J.L.Plaza,S.Jacke,Y.Chen et al.,Annealing effects on the microstructure of sputtered gold layers on oxidized silicon investigated by scanning electron microscopy and scanning probe microscopy.Philos.Mag.83,1137-1142(2003).https://doi.org/10.1080/0141861031000072006
15.Y.Huang,H.Qiu,F.Wang et al.,Effect of annealing on the characteristics of Au/Cr bilayer films grown on glass.User Model.User-Adapt.Interact.71,523-528(2003).https://doi.org/10.1016/S0042-207X(03)00093-9
16.D.L.Windt,IMD Software for modeling the optical properties of multilayer films.Comput.Phys.12,360-370(1998).https://doi.org/10.1063/1.168689
17.A.Gonza′lez-Gonza′lez,G.M.Alonzo-Medina,A.I.Oliva et al.,Morphology evolution of thermally annealed polycrystalline thin films.Phys.Rev.B Condens.Matter Mater.Phys.(2011).https://doi.org/10.1103/physrevb.84.155450
18.Y.Golan,L.Margulis,I.Rubinstein,Erratum to‘‘vacuum-deposited gold films.I.Factors affecting the film morphology’’.Surf.Sci.273,460-461(1992).https://doi.org/10.1016/0039-6028(92)90188-c
19.S.Zhou,W.Wu,T.Shao,Effect of post deposition annealing on residual stress stability of gold films.Surf.Coat.Technol.304,222-227(2016).https://doi.org/10.1016/j.surfcoat.2016.07.001
20.J.W.C.De Vries,Resistivity of thin Au films as a function of grain diameter and temperature.J.Phys.F Met.Phys.18,515(1988).https://doi.org/10.1088/0305-4608/17/9/019
2.V.Rehn,V.O.Jones,Vacuum ultraviolet(VUV)and soft X-ray mirrors for synchrotron radiation.Opt.Eng.(1978).https://doi.org/10.1117/12.7972270
3.S.Sugita,A.Furuzawa,K.Ishibashi et al.,Measurement of reflectivity of x-ray mirror for soft x-ray telescope onboard ASTRO-H.Proc.SPIE(2012).https://doi.org/10.1117/12.926711
4.K.Raiber,A.Terfort,C.Benndorf et al.,Removal of selfassembled single layers of alkanethiolates on gold by plasma cleaning.Surf.Sci.595,56-63(2005).https://doi.org/10.1016/j.susc.2005.07.038
5.A.Toyoshima,T.Kikuchi,H.Tanaka et al.,In situ removal of carbon contamination from a chromium-coated mirror:ideal optics to suppress higher-order harmonics in the carbon K-edge region.J.Synchrotron Radiat.22,1359-1363(2015).https://doi.org/10.1107/S1600577515015040
6.F.Tian,X.Li,Y.Wang et al.,Small angle X-ray scattering beamline at SSRF.Nucl.Sci.Tech.26,030101(2015).https://doi.org/10.13538/j.1001-8042/nst.26.030101
7.G.U.Kulkarni,Optimizing growth conditions for electroless deposition of Au films on Si(111)substrates.Bull.Mater.Sci.29,505-511(2006).https://doi.org/10.1007/BF02914082
8.K.Gall,N.West,K.Spark et al.,Creep of thin film Au on bimaterial Au/Si microcantilevers.Acta Mater.52(8),2133-2146(2004).https://doi.org/10.1016/j.actamat.2004.01.005
9.C.K.Malek,B.Kebabi,A.Charai et al.,Effect of thermal treatment on the mechanical and structural properties of gold thin films.J.Vac.Sci.Technol.B(USA)9,3329-3332(1991).https://doi.org/10.1116/1.585336
10.B.Sˇ.Baticˇ,T.Verbovsˇek,J.Sˇetina,Decomposition of thin Au films on flat and structured Si substrate by annealing.Vacuum138,134-138(2017).https://doi.org/10.1016/j.vacuum.2016.12.006
11.X.Zhang,X.Song,D.Zhang,Thickness dependence of grain size and surface roughness for dc magnetron sputtered Au films.Chin.Phys.B 19,086802(2010).https://doi.org/10.1088/1674-1056/19/8/086802
12.W.Tang,K.Xu,P.Wang et al.,Residual stress and crystal orientation in magnetron sputtering Au films.Mater.Lett.57,3101-3106(2003).https://doi.org/10.1016/s0167-577x(03)00004-1
13.J.Wang,B.Zhang,Y.H.Xu et al.,Research on deposition rate of TiZrV/Pd film by DC magnetron sputtering method.Nucl.Sci.Tech.28,50(2017).https://doi.org/10.1007/s41365-017-0199-6
14.J.L.Plaza,S.Jacke,Y.Chen et al.,Annealing effects on the microstructure of sputtered gold layers on oxidized silicon investigated by scanning electron microscopy and scanning probe microscopy.Philos.Mag.83,1137-1142(2003).https://doi.org/10.1080/0141861031000072006
15.Y.Huang,H.Qiu,F.Wang et al.,Effect of annealing on the characteristics of Au/Cr bilayer films grown on glass.User Model.User-Adapt.Interact.71,523-528(2003).https://doi.org/10.1016/S0042-207X(03)00093-9
16.D.L.Windt,IMD Software for modeling the optical properties of multilayer films.Comput.Phys.12,360-370(1998).https://doi.org/10.1063/1.168689
17.A.Gonza′lez-Gonza′lez,G.M.Alonzo-Medina,A.I.Oliva et al.,Morphology evolution of thermally annealed polycrystalline thin films.Phys.Rev.B Condens.Matter Mater.Phys.(2011).https://doi.org/10.1103/physrevb.84.155450
18.Y.Golan,L.Margulis,I.Rubinstein,Erratum to‘‘vacuum-deposited gold films.I.Factors affecting the film morphology’’.Surf.Sci.273,460-461(1992).https://doi.org/10.1016/0039-6028(92)90188-c
19.S.Zhou,W.Wu,T.Shao,Effect of post deposition annealing on residual stress stability of gold films.Surf.Coat.Technol.304,222-227(2016).https://doi.org/10.1016/j.surfcoat.2016.07.001
20.J.W.C.De Vries,Resistivity of thin Au films as a function of grain diameter and temperature.J.Phys.F Met.Phys.18,515(1988).https://doi.org/10.1088/0305-4608/17/9/019