Thermal conductivity and sound velocities of hydrogen-silsesquioxane low-k dielectrics -: art. no. 094205

被引:66
作者
Costescu, RM
Bullen, AJ
Matamis, G
O'Hara, KE
Cahill, DG
机构
[1] Univ Illinois, Dept Mat Sci & Engn, Coordinated Sci Lab, Urbana, IL 61801 USA
[2] Univ Illinois, Mat Res Lab, Urbana, IL 61801 USA
关键词
D O I
10.1103/PhysRevB.65.094205
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
Thermal conductivities of hydrogen-silsesquioxane thin films-Dow Corning "flowable oxide" and nanoporous "extra-low-k" spin-on dielectrics-are measured in the temperature range 80-400 K using the 3omega method. Film thickness and atomic densities are characterized by the combination of Rutherford-backscattering spectrometry and variable-angle spectroscopic ellipsometry. Measurements of the longitudinal speeds of Sound by picosecond ultrasonics and interferometry enable comparisons with the model of the minimum thermal conductivity of homogeneous materials. This model fails to capture the strong temperature dependence of the conductivity. Data for nanoporous silsesquioxane and SiO2 are compared to the predictions of effective medium theories of heterogeneous materials, Differential-effective-medium theory predicts a scaling of thermal conductivity Lambda with atomic density n. Lambdaproportional ton(3/2) in good agreement with experiment. The comparisons with effective-medium theories suggest that a greater control of pore microstructure may enable significant improvements in the thermal and mechanical properties of porous dielectrics.
引用
收藏
页码:942051 / 942056
页数:6
相关论文
共 42 条
[1]   THERMAL-CONDUCTIVITY OF DISORDERED HARMONIC SOLIDS [J].
ALLEN, PB ;
FELDMAN, JL .
PHYSICAL REVIEW B, 1993, 48 (17) :12581-12588
[2]   SINGLE-SCATTERING APPROXIMATIONS FOR COEFFICIENTS IN BIOT EQUATIONS OF POROELASTICITY [J].
BERRYMAN, JG .
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA, 1992, 91 (02) :551-571
[3]   Data reduction in 3ω method for thin-film thermal conductivity determination [J].
Borca-Tasciuc, T ;
Kumar, AR ;
Chen, G .
REVIEW OF SCIENTIFIC INSTRUMENTS, 2001, 72 (04) :2139-2147
[5]   ON ELASTIC MODULI OF SOME HETEROGENEOUS MATERIALS [J].
BUDIANSK.B .
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS, 1965, 13 (04) :223-&
[6]   Thermal conductivity of amorphous carbon thin films [J].
Bullen, AJ ;
O'Hara, KE ;
Cahill, DG ;
Monteiro, O ;
von Keudell, A .
JOURNAL OF APPLIED PHYSICS, 2000, 88 (11) :6317-6320
[7]  
Cahill D.G., 1990, Thermal Conductivity 21, P3
[8]   THERMAL-CONDUCTIVITY OF ALPHA-SIH THIN-FILMS [J].
CAHILL, DG ;
KATIYAR, M ;
ABELSON, JR .
PHYSICAL REVIEW B, 1994, 50 (09) :6077-6081
[9]   THERMAL-CONDUCTIVITY MEASUREMENT FROM 30-K TO 750-K - THE 3-OMEGA METHOD [J].
CAHILL, DG .
REVIEW OF SCIENTIFIC INSTRUMENTS, 1990, 61 (02) :802-808
[10]   LOWER LIMIT TO THE THERMAL-CONDUCTIVITY OF DISORDERED CRYSTALS [J].
CAHILL, DG ;
WATSON, SK ;
POHL, RO .
PHYSICAL REVIEW B, 1992, 46 (10) :6131-6140