Measurement of Microwave Dielectric Properties of Diamond Films Using Split-cylinder Resonator Method

doi:10.15541/jim20140629

Abstract

Abstract:

Regarding to the difficulties in measuring microwave dielectric properties of diamond films due to their characteristics of low dielectric loss and small thickness, a split-cylinder resonator apparatus was established. By measuring dielectric performances of sapphire samples with different diameters, the capability of the split-cylinder resonator for measuring low dielectric loss materials was demonstrated, and the influence of sample’s diameter on measurement results was studied. Then by using the split-cylinder resonator apparatus, dielectric properties of high quality diamond films prepared by two different methods, microwave plasma chemical vapor deposition (MPCVD) and DC arc plasma jet, were measured in the Ka band. Results show that the diamond film deposited by MPCVD method has a higher quality than that of the diamond film deposited by the DC arc plasma jet method, which is consistent with the results of their Raman and UV-visible absorption spectra. The results indicate that both the relative dielectric constant and the loss tangent of the sample deposited by MPCVD method are lower than those of the sample prepared by DC arc plasma jet method.

Key words: dielectric property, split-cylinder resonator, diamond film

CLC Number:

TQ174

SU Jing-Jie, YANG Zi, LI Yi-Feng, TANG Wei-Zhong, AN Xiao-Ming, GUO Hui. Measurement of Microwave Dielectric Properties of Diamond Films Using Split-cylinder Resonator Method[J]. Journal of Inorganic Materials, 2015, 30(7): 751-756.

Figures/Tables 8

Fig. 1 Schematic of the split-cylinder resonator for dielectric property measurement

Fig. 2 Photograph of the split-cylinder resonator for dielectric properties measurement

Table 1 Microwave dielectric properties of sapphire samples (⊥c axis) with different diameter

Diameter / mm	Frequency / GHz		tanδ /×10^-4
18.2	24.287	9.45±0.09	0.26±0.20
21.6	24.399	9.45±0.09	0.27±0.20
25.0	24.451	9.40±0.09	0.27±0.20
30.0	24.476	9.44±0.09	0.27±0.20

Fig. 3 Photos of diamond films deposited by (a) MPCVD and (b) DC Arc Plasma Jet methods

Table 2 Deposition conditions of the high quality diamond film prepared by two different methods

Method	Power /kW	Pressure /kPa	Flow rate /sccm	Temperature /℃
MPCVD	9.2	15.8	CH₄/H₂: 7/200	1030
DC Arc Plasma Jet	13.5	3.5	CH₄/H₂/Ar: 0.015/6/2 (in gas recycling mode)	1000

Fig. 4 Raman spectra of the diamond films deposited by (a) MPCVD and (b) DC Arc Plasma Jet methods

Fig. 5 UV-visible absorption spectra of the diamond films deposited by different methods

Table 3 Microwave dielectric properties of the diamond films deposited by different methods

Deposition method	Frequency /GHz		tanδ /×10^-4
MPCVD	29.280	5.60±0.07	1.38±0.22
DC Arc Plasma Jet	30.004	5.77±0.09	7.49±0.66

References 23

[1]	LI X Y, GUO H, LIU Z, et al.Applications of CVD diamond film to vacuum electronic devices.Vacuum Electronics, 2009, 4: 27-31.
[2]	NUSSNTARA H, SETIAWAN A, CHAIRUNNISA, et al. Investigation of dielectric-lined for transmission loss reduction of optical waveguide.Procedia Technology, 2013, 11: 1117-1121.
[3]	KUMAR A, KUMAR N, SINGH U, et al.Towards a 1 MW, 170 GHz gyrotron design for fusion application.Infrared Phys. Technol., 2013, 57: 1-7.
[4]	MANFRED T. Progress in gyrotron development. Fusion Eng. Des., 2003, 66-68: 69-90.
[5]	TAKAHASHI K, KAJIWARA K, ODA Y, et al.High power millimeter wave experiment of torus diamond window prototype for ITER EC H&CD system.Fusion Engineering and Design, 2013, 88(2): 85-93.
[6]	SCHEURING A, PROBST P, STOCKHAUSEN A, et al.Dielectric RF Properties of CVD Diamond Disks from Sub-mm Wave to THz Frequencies. 35th Int. Conf. on Infrared, Millimeter, and THz Waves, Rome, 2010: 1-2.
[7]	SHUKLA B K, BABU R, KUSHWAH M, et al.High-power test of chemical vapor deposited diamond window for an ECRH system in SST-1.IEEE Transactions on Plasma Science, 2013, 41(7): 1794-1798.
[8]	SCHERER T A, STRAUSS D, TORGE M, et al.Investigations of Dielectric RF Properties of Ultra Low Loss CVD Diamond Disks for Fusion Applications. 34th Int. Conf. on Infrared, Millimeter, and THz Waves, Tucson, 2009: 1-2.
[9]	YANG X, BORIE E, DAMMERTZ G, et al.The influence of window parameters on the transmission characterisitics of millimeter waves.Int. J. Infrared Milli. Waves, 2003, 24(11): 1805-1813.
[10]	POLYAKOV V I, RUKOVISHNIKOV A I, GARIN B M, et al.Electrically active defects, conductivity, and millimeter wave dielectric loss in CVD diamonds.Diamond Relat. Mater., 2005, 14(3-7): 604-607.
[11]	XIN H W, ZHANG Z M, LING X, et al.Composite diamond films with smooth surface and the structural influence on dielectric properties.Diamond Relat. Mater., 2002, 11(2): 228-233.
[12]	LU F X, ZHANG H D, TONG Y M, et al.Dielectric property of thick freestanding diamond films by high power arcjet operating at gas recycling mode.Diamond Relat. Mater., 2004, 13(9): 1714-1718.
[13]	JANEZIC M D, KUESTER E F, BAKER-JARVIS J.Broadband complex permittivity measurements of dielectric substrates using a split-cylinder resonator.2004 IEEE MIT-S Digest, 2004, 1817-1820.
[14]	JANEZIC M D.Nondestructive Relative Permittivity and Loss Tangent Measurements Using a Split-cylinder Resonator. Denver: University of Colorado, 2003.
[15]	SHAPIRO M A, MOELLER C P, TEMKIN R J, et al.Electromagnetic analysis and cold test of a distributed window for a high power gyrotron.Int. J. Infrared and Millimeter Waves, 1999, 20(4): 533-542.
[16]	SILVA F, HASSOUNI K, BONNIN X, et al.Microwave engineering of plasma-assisted CVD reactors for diamond deposition.J. Phys.: Condens. Matter, 2009, 21(36): 364202.
[17]	LU F X, LI C M, TONG Y M, et al. Application of high power DC arc plasma for mass production of high quality freestanding diamond films and diamond film coated cutting tools. Mater. Sci. Forum, 2010, 654-656: 1694-1699.
[18]	SU J J, LI Y F, DING M H, et al.A dome-shaped cavity type microwave plasma chemical vapor deposition reactor for diamond ﬁlms deposition.Vacuum, 2014, 107: 51-55.
[19]	PRAWER S, NEMANICH R J.Raman spectroscopy of diamond and doped diamond.Philos. Trans. R. Soc. London, Ser. A, 2004, 362: 2537-2565.
[20]	GONON P, GHEERAERT E, DENEUVILLE A, et al.Raman study of diamond films deposited by MPCVD: effect of the substrate position.Thin Solid Films, 1995, 256(1-2): 13-22.
[21]	GARRIDO O S, ALEIXANDRE C G, OLIAS J S, et al.Dielectric and Raman spectroscopy of MWCVD diamond thin films.J. Mater. Sci. - Mater. Electron., 1996, 7: 297-303.
[22]	IBARRA A, GONZÁLEZ M, VILA R, et al. Wide frequency dielectric properties of CVD diamond.Diamond Relat. Mater., 1997, 6: 856-859.
[23]	XU P, YANG J, QIU T.The progress of output window materials.Bulletin of the Chinese Ceramic Society, 2007, 26(6): 1160-1164.