Cross-Plane Phonon Conduction in Polycrystalline Silicon Films

Silicon films of submicrometer thickness play a central role in many advanced technologies for computation and energy conversion. Numerous thermal conductivity data for silicon films are available in the literature, but they are mainly for the lateral, or in-plane, direction for both polycrystalline and single crystalline films. Here, we use time-domain thermoreflectance (TDTR), transmission electron microscopy, and semiclassical phonon transport theory to investigate thermal conduction normal to polycrystalline silicon (polysilicon) films of thickness 79, 176, and 630 nm on a diamond substrate. The data agree with theoretical predictions accounting for the coupled effects of phonon scattering on film boundaries and defects related to grain boundaries. Using the data and the phonon transport model, we extract the normal, or cross-plane thermal conductivity of the polysilicon (11.3 ± 3.5, 14.2 ± 3.5, and 25.6 ± 5.8 W m−1 K−1 for the 79, 176, and 630 nm films, respectively), as well as the thermal boundary resistance between polysilicon and diamond (6.5–8 m2 K GW−1) at room temperature. The nonuniformity in the extracted thermal conductivities is due to spatially varying distributions of imperfections in the direction normal to the film associated with nucleation and coalescence of grains and their subsequent columnar growth.

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Phonon Conduction Normal to Polysilicon Films on Diamond

ASME 2013 4th International Conference on Micro/Nanoscale Heat and Mass Transfer ◽

10.1115/mnhmt2013-22171 ◽

2013 ◽

Cited By ~ 4

Author(s):

Jungwan Cho ◽

Pane C. Chao ◽

Mehdi Asheghi ◽

Kenneth E. Goodson

Keyword(s):

Thermal Conductivity ◽

Transport Theory ◽

Phonon Scattering ◽

Phonon Transport ◽

Silicon Films ◽

Silicon Thin Films ◽

Transmission Electron ◽

Crystal Films ◽

Polysilicon Films ◽

Polycrystalline Silicon Films

Silicon films of thickness near and below one micrometer play a central role in many advanced technologies for computation and energy conversion. Numerous data on the thermal conductivity of silicon thin films are available in the literature, but mainly for the in-plane thermal conductivity of polycrystalline and single-crystal films. Here we use picosecond time-domain thermoreflectance (TDTR), transmission electron microscopy, and phonon transport theory to investigate heat conduction normal to polycrystalline silicon films on diamond substrates. The data agree with predictions that account for the coupled effects of phonon scattering on film boundaries and defects concentrated near grain boundaries. Using the data and the model, we estimate the polysilicon-diamond interface resistance to be 6.5–8 m2 K GW−1.

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Thermal conductivity of heavily doped low‐pressure chemical vapor deposited polycrystalline silicon films

Journal of Applied Physics ◽

10.1063/1.339924 ◽

1988 ◽

Vol 63 (5) ◽

pp. 1442-1447 ◽

Cited By ~ 105

Author(s):

Y. C. Tai ◽

C. H. Mastrangelo ◽

R. S. Muller

Keyword(s):

Thermal Conductivity ◽

Polycrystalline Silicon ◽

Chemical Vapor ◽

Low Pressure ◽

Silicon Films ◽

Chemical Vapor Deposited ◽

Pressure Chemical ◽

Heavily Doped ◽

Polycrystalline Silicon Films

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Effect of Nanocavities on the Thermoelectric Properties of Polycrystalline Silicon

MRS Proceedings ◽

10.1557/opl.2011.1465 ◽

2011 ◽

Vol 1329 ◽

Cited By ~ 1

Author(s):

Ekaterina Selezneva ◽

Andrea Arcari ◽

Gilles Pernot ◽

Elisabetta Romano ◽

Gianfranco Cerofolini ◽

...

Keyword(s):

Thermal Conductivity ◽

Electrical Conductivity ◽

Seebeck Coefficient ◽

Thermoelectric Properties ◽

Polycrystalline Silicon ◽

Figure Of Merit ◽

Annealing Temperature ◽

Silicon Films ◽

Negative Effect ◽

Polycrystalline Silicon Films

ABSTRACTNanostructuring has opened new ways to increase the thermoelectric performance of a host of materials, mainly by decreasing their thermal conductivity κ while preserving the Seebeck coefficient S and electrical conductivity σ. The thermoelectric properties of degenerated polycrystalline silicon films with nanocavities (NCs) have been studied as a function of annealing temperature upon isochronous annealings in argon carried out every 50°C in the range 500 – 1000°C which were used to modify the shape of the NCs. We found that presence of the NCs had no negative effect on the electronic properties of the system. The measured values of S and σ were close to those previously reported for the blank polycrystalline silicon films with the same doping level. The thermal conductivity was also found to be close to the value measured on the blank sample, about half of the reported value in polycrystals. This led to a power factor of 15.2 mWm-1K-2 and a figure of merit of 0.18 at 300 K.

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Erratum: ‘‘Thermal conductivity of heavily doped low‐pressure chemical vapor deposited polycrystalline silicon films’’ [J. Appl. Phys. 63, 1442 (1988)]

Journal of Applied Physics ◽

10.1063/1.344503 ◽

1989 ◽

Vol 66 (7) ◽

pp. 3420-3420 ◽

Cited By ~ 4

Author(s):

Y. C Tai ◽

C. H. Mastrangelo ◽

R. S. Muller

Keyword(s):

Thermal Conductivity ◽

Polycrystalline Silicon ◽

Chemical Vapor ◽

Low Pressure ◽

Silicon Films ◽

Chemical Vapor Deposited ◽

Pressure Chemical ◽

Heavily Doped ◽

Polycrystalline Silicon Films

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Interface morphology of thermal oxide grown on polycrystalline silicon by different processes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131619 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1396-1397

Author(s):

H. Yen ◽

E. P. Kvam ◽

R. Bashir ◽

S. Venkatesan ◽

G. W. Neudeck

Keyword(s):

Integrated Circuits ◽

Polycrystalline Silicon ◽

Silicon Films ◽

Interface Morphology ◽

Oxide Interface ◽

Poly Silicon ◽

Thermal Oxide ◽

Grain Orientations ◽

Polycrystalline Silicon Films ◽

P Type

Polycrystalline silicon, when highly doped, is commonly used in microelectronics applications such as gates and interconnects. The packing density of integrated circuits can be enhanced by fabricating multilevel polycrystalline silicon films separated by insulating SiO2 layers. It has been found that device performance and electrical properties are strongly affected by the interface morphology between polycrystalline silicon and SiO2. As a thermal oxide layer is grown, the poly silicon is consumed, and there is a volume expansion of the oxide relative to the atomic silicon. Roughness at the poly silicon/thermal oxide interface can be severely deleterious due to stresses induced by the volume change during oxidation. Further, grain orientations and grain boundaries may alter oxidation kinetics, which will also affect roughness, and thus stress.Three groups of polycrystalline silicon films were deposited by LPCVD after growing thermal oxide on p-type wafers. The films were doped with phosphorus or arsenic by three different methods.

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