Heat Capacity of Copper Thin Films Measured by Micro Pulse Calorimeter

2008 ◽  
Author(s):  
Jun Yu ◽  
Zhen’an Tang ◽  
Fengtian Zhang ◽  
Haitao Ding ◽  
Zhengxing Huang
Keyword(s):  
Thin Films ◽  
Heat Capacity ◽  
Specific Heat ◽  
Heat Capacities ◽  
Nanometer Scale ◽  
Cu Films ◽  
Cu Film ◽  
Thermal Link ◽  
Measure Heat Capacity ◽  
Impurities And Defects

Thermal properties of thin films may differ from the bulk value due to the differences in microstructure, such as the grain size, impurities and defects. Heat capacity is one of the thermophysical properties and it is measured by calorimetry. However, traditional calorimeters can’t measure heat capacity of thin films which are quasi-2D and has small heat capacity. Recently, micro calorimeters with suspending membrane structure have been developed to measure the heat capacity of ultra thin films with thickness of sub-micrometer to nanometer scale. Efforts are focused on reducing heat capacitance of the addenda and minimizing the thermal link so as to permit an adiabatic measurement of the heat capacity of thin film. In this paper, a micro pulse calorimeter was developed and heat capacities of the copper thin films were measured by the micro pulse calorimetry. The heating rate of the micro calorimeter is up to 200K/ms with heating power of 4.5mW, and the heat capacity of the calorimeter is about 23.4nJ/K at 300K. Heat capacities of polycrystalline copper thin films with thickness from 20nm to 340nm were measured in the temperature range from 300K to 420K in vacuum of 1mPa. In order to extract the specific heat of the Cu films, mass of the films was calculated with volume and density of the sample film. The specific heat of the Cu films was compared with the literature values of bulk Cu. The specific heat of the 340nm Cu film is close to the literature data of bulk Cu. For the thinner films, enhanced specific heat was observed, and the data shows that the specific heat increases with the decreasing of crystalline size and film thickness.

Measurement of the Heat Capacity of Copper Thin Films Using a Micropulse Calorimeter

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
Jun Yu ◽  
Zhen’an Tang ◽  
Fengtian Zhang ◽  
Haitao Ding ◽  
Zhengxing Huang
Keyword(s):  
Thin Films ◽  
Heat Capacity ◽  
Specific Heat ◽  
Measurement Errors ◽  
Heat Capacity Measurement ◽  
Average Crystalline Size ◽  
Capacity Measurement ◽  
Cu Film ◽  
20 Nm ◽  
Data Processing Methods

This paper presents a micropulse calorimeter for heat capacity measurement of thin films. Optimization of the structure and data processing methods of the microcalorimeter improved the thermal isolation and temperature uniformity and reduced the heat capacity measurement errors. Heat capacities of copper thin films with thicknesses from 20 nm to 340 nm are measured in the temperature range from 300 K to 420 K in vacuum of 1 mPa. The specific heat of the 340 nm Cu film is close to the literature data of bulk Cu. For the thinner films, the data shows that the specific heat increases with the decreasing of film thickness (or the average crystalline size).

RESIDUAL STRESS DEVELOPMENT IN CU THIN FILMS WITH AND WITHOUT AlN PASSIVATION BY CYCLIC PLANE BENDING

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2530-2536
Author(s):  
MITSUHIKO SHINOHARA ◽  
TAKAO HANABUSA ◽  
KAZUYA KUSAKA
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Diffraction Method ◽  
Micro Electro Mechanical System ◽  
Passivation Layer ◽  
X Ray Diffraction ◽  
Cu Films ◽  
Cu Film ◽  
Bending Fatigue Test ◽  
Plane Bending

Since the thin film technology is applied to micro-machines, MEMS (micro electro-mechanical system), optical devices and others, the evaluation of mechanical properties in thin films becomes to be important. On the other hand, there are differences in mechanical properties between bulk materials and thin films, but studies in this field have not yet been made enough. The present paper reports on the evaluation of the mechanical properties of Cu thin films with and without AlN passivation layer. Specimens with different thickness of Cu film were subjected to cyclic plane bending fatigue test. Residual stresses developed in the Cu films were measured in a sequence of bending cycles using X-ray diffraction method in order to understand the effect of film thickness and passivation layer on mechanical properties of Cu thin films.

scholarly journals Nanoindentation of Au and Pt/Cu thin films at elevated temperatures

2004 ◽  
Vol 19 (9) ◽  
pp. 2650-2657 ◽  
Author(s):  
Alex A. Volinsky ◽  
Neville R. Moody ◽  
William W. Gerberich
Keyword(s):  
Thin Films ◽  
Elastic Modulus ◽  
Yield Stress ◽  
Elevated Temperatures ◽  
Nanocrystalline Structure ◽  
Cu Films ◽  
Interfacial Toughness ◽  
Film Hardness ◽  
Cu Film ◽  
Sputter Deposited

This paper describes the nanoindentation technique for measuring sputter-deposited Au and Cu thin films’ mechanical properties at elevated temperatures up to 130 °C. A thin, 5-nm Pt layer was deposited onto the Cu film to prevent its oxidation during testing. Nanoindentation was then used to measure elastic modulus and hardness as a function of temperature. These tests showed that elastic modulus and hardness decreased as the test temperature increased from 20 to 130 °C. Cu films exhibited higher hardness values compared to Au, a finding that is explained by the nanocrystalline structure of the film. Hardness was converted to the yield stress using both the Tabor relationship and the inverse method (based on the Johnson cavity model). The thermal component of the yield-stress dependence followed a second-order polynomial in the temperature range tested for Au and Pt/Cu films. The decrease in yield stress at elevated temperatures accounts for the increased interfacial toughness of Cu thin films.

“TEMPERATURE” FLUCTUATION AND HEAT CAPACITIES OF QUARKS AND π MESON

2007 ◽  
Vol 16 (07n08) ◽  
pp. 1912-1916
Author(s):  
X. H. SHI ◽  
G. L. MA ◽  
Y. G. MA ◽  
X. Z. CAI ◽  
J. H. CHEN
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Impact Parameter ◽  
Specific Heat Capacity ◽  
Temperature Fluctuation ◽  
Temperature Fluctuations ◽  
Heat Capacities ◽  
Transverse Mass ◽  
Parton Cascade ◽  
Specific Heat Capacities

Specific heat capacities of π meson and different quarks after parton cascade AMPT model in Au + Au collisions at [Formula: see text] have been tentatively extracted from the event-by-event temperature fluctuations in the region of low transverse mass. The specific heat capacity of π meson shows a slight dropping trend with increasing impact parameter. The specific heat capacities of different quarks increase with the mass of quark, and the sum of up and down quark's specific heat capacities was found to be approximately equal to that of π meson.

Thermomechanical Behavior and Properties of Passivated Pvd and Ecd Cu Thin Films

2005 ◽  
Vol 875 ◽  
Author(s):  
M. Gregoire ◽  
S. Kordic ◽  
P. Gergaud ◽  
O. Thomas ◽  
M. Ignat
Keyword(s):  
Thin Films ◽  
Thermal Cycling ◽  
Grain Growth ◽  
Impurity Content ◽  
Thermomechanical Behavior ◽  
Temperature Curve ◽  
Cu Films ◽  
Texture Change ◽  
Cu Film ◽  
Electrochemically Deposited

AbstractThe thermomechanical behavior is investigated of SiCN-encapsulated blanket Physical Vapor Deposited (PVD) and Electrochemically Deposited (ECD) Cu films. At lower ECD Cu film thicknesses an anomalous shape and a tail of the stress-temperature curve are observed, which are not caused by impurities at the interfaces, but are correlated to highly textured microstructure. Repeated thermal cycling of up to 400 °C does not markedly change the texture of the films, but a significant texture change takes place with increasing ECD Cu thickness. Thermal cycling induces grain growth for thicker films only. Impurity content and distribution in the PVD films do not change due to cycling.

scholarly journals HEAT CAPACITY PROPERTIES OF AQUEOUS BUFFER SOLUTIONS OF L-HISTIDINE IN A WIDE TEMPERATURE RANGE

2019 ◽  
Vol 62 (11) ◽  
pp. 78-84
Author(s):  
Elena Yu. Tyunina ◽  
Anna A. Kuritsyna
Keyword(s):  
Heat Capacity ◽  
Amino Acid ◽  
Specific Heat ◽  
Sodium Phosphate ◽  
Heat Capacities ◽  
Buffer Solution ◽  
Partial Molar Heat Capacities ◽  
Aqueous Buffer ◽  
Temperature Range ◽  
Buffer Solutions

The influence of temperature and concentration of L-histidine on the heat capacity properties of its aqueous buffer solutions was studied by differential scanning calorimetry. The investigations were carried out in aqueous buffer solutions (pH 7.4) containing monobasic sodium phosphate and dibasic sodium phosphate, which brings the environment closer to the conditions of real biological systems. The pH values of the solutions were fixed with a digital pH meter Mettler Toledo, model Five-Easy (Switzerland). The differential scanning microcalorimeter SCAL-1 (Biopribor, Pushchino, Russia) was used for measure the specific heat capacity of the system under study. It was equipped with Peltier thermoelectric elements, two measuring glass cells with an internal volume of 0.377 cm3, as well as a computer terminal and software for calculating heat capacity. The standard error of measurement of the specific heat for the studied solutions was within ±7·10-3 J·K-1·g-1. The experimental values of the specific heat of solutions of the amino acid in a phosphate buffer solvent in the temperature range (283.15 – 343.15) K were obtained. The concentration of histidine was varied from (0.00215 to 0.03648) mol·kg-1. All the studied solutions were prepared by the gravimetric method using Sartorius-ME215S scales (with a weighing accuracy of 1·10-5 g). The apparent molar heat capacities of L-histidine in the buffer solution, as well as its partial molar heat capacities at infinite dilution, were determined. The calculated molar parameters increase with an increase in both temperature and amino acid concentration. It was shown that the partial molar heat capacities transfers of L-histidine from water to the buffer solution have positive values in the temperature range studied. The results are discussed on base of the Gurney model.

The Nanomechanical Effect of Dendrimer Interlayers Underneath Cu Ultrathin Films

2002 ◽  
Vol 734 ◽  
Author(s):  
Junyan Zhang ◽  
Micheal Curry ◽  
Shane Street
Keyword(s):  
Thin Films ◽  
Ultrathin Films ◽  
Room Temperature ◽  
Native Oxide ◽  
Cu Films ◽  
Dc Sputtering ◽  
Repeat Units ◽  
Cu Film

ABSTRACTTwo kinds of dendrimers, DAB and PAMAM (with the same terminal groups but different branched repeat units), were chosen as interlayers for Cu ultrathin films deposited on native oxide Si(100) wafers. 10 nm Cu thin films were deposited directly on the dendrimer monolayers by DC sputtering at room temperature. The nanomechanical results show that PAMAM and DAB have significant effects on the properties of the resulting films, with the DAB layer acting as a stiffer ‘spring’, compared to PAMAM, underneath the Cu films. Both dendrimer interlayers lower the hardness of the film, compared to Cu alone; the effect is greater for PAMAM than DAB interlayers. However, the introduction of either dendrimer monolayer significantly increased the elasticity of the Cu film.

scholarly journals Suitable model for the calculation of the correlation between the real and the average specific heat capacity and possibilities of its application

2013 ◽  
Vol 67 (3) ◽  
pp. 495-511
Author(s):  
Branko Pejovic ◽  
Ljubica Vasiljevic ◽  
Vladan Micic ◽  
Mitar Perusic
Keyword(s):  
Heat Capacity ◽  
Specific Heat ◽  
Specific Heat Capacity ◽  
Heat Capacities ◽  
Practical Significance ◽  
Suitable Model ◽  
The Real ◽  
Temperature Range ◽  
Specific Heat Capacities ◽  
Differential Properties

Starting from the definition of the average specific heat capacity for chosen temperature range, the analytic dependence between the real and the mean specific heat capacities is obtained using differential and integral calculation. The obtained relation in differential form for the defined temperature range allows for the problem to be solved directly, without any special restrictions on its use. Using the obtained relation, a general model in the form of a polynomial of arbitrary degree in the function of temperature was derived, which has more suitable and faster practical application and is more general in character than the existing model. New graphical method for solving the problem is obtained based on differential geometry and using the derived equation. This may also have practical significance since many problems in thermodynamics are solved analytically and graphically. This result was used in order to obtain the amount of specific heat exchanged using an analytical model or a planimetric method. In addition, this graphical solution was used for the construction of the diagram showing the dependence between the specific heat exchanged and temperature. This diagram also gives a simple graphical procedure for the calculation of the real and the average specific heat capacity for arbitrary temperature or temperature interval. The confirmation for all graphic constructions is obtained using the differential properties between thermodynamic units. In order for the graphical solutions presented to be applicable in practice, suitable ratio coefficients have been determined for all cases. Verification of the model presented, as well as the possibilities of its application, were given using several characteristic examples of semi-ideal and real gas. Apart from linear and non-linear functions in the form of polynomials, the exponential function of the dependence between specific heat capacities and temperature was also analysed in this process.

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