Temperature Dependence of Thermal Conductivity of Amorphous and Crystal Thin Film by Molecular Dynamics Simulation

2007 ◽  
Author(s):  
Zhengxing Huang ◽  
Zhenan Tang ◽  
Suyuan Bai ◽  
Jun Yu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Integrated Circuits ◽  
Temperature Dependence ◽  
Amorphous Materials ◽  
Dynamics Simulation ◽  
Amorphous Sio2 ◽  
Film Boundary ◽  
Different Temperatures

For crystal materials, thermal conductivity (TC) is proportional to T3 at low temperatures and to T−1 at high temperatures. TCs of most amorphous materials decrease with the decreasing temperatures. If a material is thin film, boundary will influence the TC and then influence the temperature dependence. In this paper, we calculate the TC of crystal and amorphous SiO2 thin films, which is a commonly used material in micro devices and Integrated Circuits, by NEMD simulations. The calculation temperatures are from 100K to 700K and the thicknesses are from 2nm to 8nm. TCs of crystal thin films reach their peak values at different temperatures for different thicknesses. The smaller thickness the larger peak values obtained. But for amorphous thin films, the results show that the temperature dependence of thin films is the same as bulk materials and not relative to their thicknesses. The obtained temperature dependence of the thin films is consistent with some previous measurements and the theory predictions.

Molecular Dynamics Simulation on the Out-of Plane Thermal Conductivity of Single-Crystal Carbon Thin Films

2009 ◽  
Vol 60-61 ◽  
pp. 430-434 ◽  
Author(s):  
Xing Li Zhang ◽  
Zhao Wei Sun ◽  
Guo Qiang Wu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Potential Energy ◽  
Film Thickness ◽  
Single Crystal ◽  
Diamond Crystal ◽  
Dynamics Simulation ◽  
Crystal Direction

In this article, we select corresponding Tersoff potential energy to build potential energy model and investigate the thermal conductivities of single-crystal carbon thin-film. The equilibrium molecular dynamics (EMD) method is used to calculate the nanometer thin film thermal conductivity of diamond crystal at crystal direction (001), and the non-equilibrium molecular dynamics (NEMD) is used to calculate the nanometer thin film thermal conductivity of diamond crystal at crystal direction (111). The results of calculations demonstrate that the nanometer thin film thermal conductivity of diamond crystal is remarkably lower than the corresponding bulk experimental data and increase with increasing the film thickness, and the nanometer thin film thermal conductivity of diamond crystal relates to film thickness linearly in the simulative range. The nanometer thin film thermal conductivity also demonstrates certain regularity with the change of temperature. This work shows that molecular dynamics, applied under the correct conditions, is a viable tool for calculating the thermal conductivity of nanometer thin films.

A HRTEM Study of Resistive Switching Behaviour in SiO2 Thin Films by Sol-Gel Process

2011 ◽  
Vol 687 ◽  
pp. 1-6 ◽  
Author(s):  
Ying Li ◽  
Gao Yang Zhao ◽  
Xiao Fei Zhou ◽  
Li Ning Pan ◽  
Yang Ren
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Resistive Switching ◽  
Sol Gel ◽  
Switching Behavior ◽  
Amorphous Sio2 ◽  
Sio2 Thin Film ◽  
Different Temperatures ◽  
High Resolution Images ◽  
Sandwiched Structure

Amorphous SiO2 thin films were fabricated at different temperatures using sol-gel technique. The unipolar resistive switching behavior was observed in Cu/ SiO2/ ATO (SnO2: Sb) sandwiched structure when the SiO2 thin film annealed at 500°C. The average ratio of Roff /Ron is 102. We investigated the successful device using HRTEM and XPS. It shows that the Cu defuses into the SiO2 thin film and it forms CuSiO3 in the interface between SiO2 and ATO films according to the high resolution images.

scholarly journals Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Coatings ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Weiguang Zhang ◽  
Jijun Li ◽  
Yongming Xing ◽  
Xiaomeng Nie ◽  
Fengchao Lang ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Integrated Circuits ◽  
Film Thickness ◽  
Depth Range ◽  
Micro Electro Mechanical Systems ◽  
Si Substrates ◽  
Sio2 Thin Film ◽  
Average Grain Size

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

scholarly journals Optimizing the Properties of La0.8Sr0.2CrO3 Thin Films through Post-Annealing for High-Temperature Sensing

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1802
Author(s):  
Dan Liu ◽  
Peng Shi ◽  
Yantao Liu ◽  
Yijun Zhang ◽  
Bian Tian ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Annealing Temperature ◽  
Rf Sputtering ◽  
Maximum Size ◽  
Cross Sectional ◽  
Post Annealing ◽  
Maximum Conductivity ◽  
Different Temperatures ◽  
Post Annealing Temperature

La0.8Sr0.2CrO3 (0.2LSCO) thin films were prepared via the RF sputtering method to fabricate thin-film thermocouples (TFTCs), and post-annealing processes were employed to optimize their properties to sense high temperatures. The XRD patterns of the 0.2LSCO thin films showed a pure phase, and their crystallinities increased with the post-annealing temperature from 800 °C to 1000 °C, while some impurity phases of Cr2O3 and SrCr2O7 were observed above 1000 °C. The surface images indicated that the grain size increased first and then decreased, and the maximum size was 0.71 μm at 1100 °C. The cross-sectional images showed that the thickness of the 0.2LSCO thin films decreased significantly above 1000 °C, which was mainly due to the evaporation of Sr2+ and Cr3+. At the same time, the maximum conductivity was achieved for the film annealed at 1000 °C, which was 6.25 × 10−2 S/cm. When the thin films post-annealed at different temperatures were coupled with Pt reference electrodes to form TFTCs, the trend of output voltage to first increase and then decrease was observed, and the maximum average Seebeck coefficient of 167.8 µV/°C was obtained for the 0.2LSCO thin film post-annealed at 1100 °C. Through post-annealing optimization, the best post-annealing temperature was 1000 °C, which made the 0.2LSCO thin film more stable to monitor the temperatures of turbine engines for a long period of time.

Determination of Thermal Conductivity of Amorphous Silicon Thin Films via Non-Contacting Optical Probing

2006 ◽  
Vol 326-328 ◽  
pp. 689-692
Author(s):  
Seung Jae Moon
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Amorphous Silicon ◽  
Optical Transmission ◽  
Film Deposition ◽  
Transmission Measurement ◽  
Conductive Heat ◽  
Optical Transmission Measurement

The thermal conductivity of amorphous silicon (a-Si) thin films is determined by using the non-intrusive, in-situ optical transmission measurement. The thermal conductivity of a-Si is a key parameter in understanding the mechanism of the recrystallization of polysilicon (p-Si) during the laser annealing process to fabricate the thin film transistors with uniform characteristics which are used as switches in the active matrix liquid crystal displays. Since it is well known that the physical properties are dependent on the process parameters of the thin film deposition process, the thermal conductivity should be measured. The temperature dependence of the film complex refractive index is determined by spectroscopic ellipsometry. A nanosecond KrF excimer laser at the wavelength of 248 nm is used to raise the temperature of the thin films without melting of the thin film. In-situ transmission signal is obtained during the heating process. The acquired transmission signal is fitted with predictions obtained by coupling conductive heat transfer with multi-layer thin film optics in the optical transmission measurement.

The Study on Young's Modulus of Multilayered Cu/Ni Multilayered Nano Thin Films by Molecular Dynamics Simulation

2014 ◽  
Vol 513-517 ◽  
pp. 113-116
Author(s):  
Jen Ching Huang ◽  
Fu Jen Cheng ◽  
Chun Song Yang
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Strain Rate ◽  
Young’S Modulus ◽  
Potential Function ◽  
Dynamics Simulation ◽  
System Temperature ◽  
Simulation Results

The Youngs modulus of multilayered nanothin films is an important property. This paper focused to investigate the Youngs Modulus of Multilayered Ni/Cu Multilayered nanoThin Films under different condition by Molecular Dynamics Simulation. The NVT ensemble and COMPASS potential function were employed in the simulation. The multilayered nanothin film contained the Ni and Cu thin films in sequence. From simulation results, it is found that the Youngs modulus of Cu/Ni multilayered nanothin film is different at different lattice orientations, temperatures and strain rate. After experiments, it can be found that the Youngs modulus of multilayered nanothin film in the plane (100) is highest. As thickness of the thin film and system temperature rises, Youngs modulus of multilayered nanothin film is reduced instead. And, the strain rate increases, the Youngs modulus of Cu/Ni multilayered nanothin film will also increase.

Improvement of Thermal Conductivity of Electroplated Copper Thin-Film Interconnections by Controlling Their Micro Texture

2014 ◽  
Author(s):  
Pornvitoo Rittinon ◽  
Ken Suzuki ◽  
Hideo Miura
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thermal Conductivity ◽  
Grain Boundaries ◽  
Diffraction Method ◽  
Electron Back Scatter Diffraction ◽  
High Resistivity ◽  
Copper Thin Film ◽  
Electroplated Copper ◽  
The Relationship

Copper thin films are indispensable for the interconnections in the advanced electronic products, such as TSV (Trough Silicon Via), fine bumps, and thin-film interconnections in various devices and interposers. However, it has been reported that both electrical and mechanical properties of the films vary drastically comparing with those of conventional bulk copper. The main reason for the variation can be attributed to the fluctuation of the crystallinity of grain boundaries in the films. Porous or sparse grain boundaries show very high resistivity and brittle fracture characteristic in the films. Thus, the thermal conductivity of the electroplated copper thin films should be varied drastically depending on their micro texture based on the Wiedemann-Franz’s law. Since the copper interconnections are used not only for the electrical conduction but also for the thermal conduction, it is very important to quantitatively evaluate the crystallinity of the polycrystalline thin-film materials and clarify the relationship between the crystallinity and thermal properties of the films. The crystallinity of the interconnections were quantitatively evaluated using an electron back-scatter diffraction method. It was found that the porous grain boundaries which contain a significant amount of vacancies increase the local electrical resistance in the interconnections, and thus, cause the local high Joule heating. Such porous grain boundaries can be eliminated by control the crystallinity of the seed layer material on which the electroplated copper thin film is electroplated.

CuxSbySz THIN FILMS PRODUCED BY ANNEALING CHEMICALLY DEPOSITED Sb2S3-CuS THIN FILMS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 667-670 ◽  
Author(s):  
Y. RODRÍGUEZ-LAZCANO ◽  
M. T. S. NAIR ◽  
P. K. NAIR
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Band Gap ◽  
Deposition Method ◽  
Photovoltaic Devices ◽  
Large Area ◽  
Electrical And Optical Properties ◽  
Ternary Compounds ◽  
Glass Substrates ◽  
Different Temperatures

The possibility of generating ternary compounds through annealing thin film stacks of binary composition has been demonstrated before. In this work we report a method to produce large area coating of ternary compounds through a reaction in solid state between thin films of Sb2S3 and CuS. Thin films of Sb2S3 -CuS were deposited on glass substrates in the sequence of Sb2S3 followed by CuS (on Sb2S3 ) using chemical bath deposition method. The multilayer stack, thus produced, of approximately 0.5 μm in thickness, where annealed under nitrogen and argon atmospheres at different temperatures to produce films of ternary composition, CuxSbySz . An optical band gap of ~1.5 eV was observed in these films, suggesting that the thin films of ternary composition formed in this way are suitable for use as absorber materials in photovoltaic devices. The results on the analyses of structural, electrical and optical properties of films formed with different combinations of thickness in the multilayers will be discussed in the paper.

scholarly journals Optical and Electrical Properties of Thin Films of CuS Nanodisks Ensembles Annealed in a Vacuum and Their Photocatalytic Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
J. Santos Cruz ◽  
S. A. Mayén Hernández ◽  
F. Paraguay Delgado ◽  
O. Zelaya Angel ◽  
R. Castanedo Pérez ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Hydrogen Peroxide ◽  
Photocatalytic Activity ◽  
Electrical Properties ◽  
Absolute Temperature ◽  
Glass Substrates ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Blue Solution

Effects on the optical, electrical, and photocatalytic properties of undoped CuS thin films nanodisks vacuum annealed at different temperatures were investigated. The chemical bath prepared CuS thin films were obtained at 40°C on glass substrates. The grain size of13.5±3.5 nm was computed directly from high-resolution transmission electron microscopy (HRTEM) images. The electrical properties were measured by means of both Hall effect at room temperature and dark resistivity as a function of the absolute temperature 100–330 K. The activation energy values were calculated as 0.007, 0.013, and 0.013 eV for 100, 150, and 200°C, respectively. The energy band gap of the films varied in the range of 1.98 up to 2.34 eV. The photocatalytic activity of the CuS thin film was evaluated by employing the degradation of aqueous methylene blue solution in the presence of hydrogen peroxide. The CuS sample thin film annealed in vacuum at 150°C exhibited the highest photocatalytic activity in presence of hydrogen peroxide.

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