| Recent years, nanomaterials have attracted great interest due to their significantphysical and chemical properties which different from those of the bulkmaterials,including opic, magnetic, electronic, catalytic and thermodynamicproperties. Since1954, Takagi tested and verified that ultrafine metallic nanocrystalsmelt below their corresponding bulk melting temperature through experiments;thethermal properties and the technology for nanomaterials’preparation have beenintensively studied experimentally and theoretically.In turns, the thermal stabilities ofnanomaterials have been deeply studied.Due to the need on the industrial manufacture and applications, the performanceof nanomatierials has attracted a large number of researchers to study from bothexperiments and theories. The thermodynamic parameters have played important roleson ensuring the performance of nanomaterials. In addition,it becomes a significantsubject on how to improve the thermal and phase stabilities of nanomaterials. It isrelated to many properties of nanomaterials, the Curie transition of ferromagnetic,ferrelectric nanocrystals, the Néel transition of antiferromagnetic and the criticaltransition of superconductive nanocrystals for instance. Melting property is one of thebasic physical properties on materials，which also determine the thermodynamicstability of materials. These properties of thermal and phase stabilities are of concernfor designing and governing materials for applications in practice. Meltingtemperature is related to other physical properties, such as activation energy, cohesiveenergy, glass transition temperature, freezing temperature, ferromagnetic temperature,and ferroelectric temperature etc. Hence, rechearching on the melting mechanism isssignificant for designing and governing materials for applications. For the present,themelt mechanism for both bulk and nanomaterials has made some progress throughdecades of effort; it tends to be reach perfection. But other properties of nanomaterialshave not been characterized by good theries. In this paper, the discussion of the thermodynamic patameters related to Photoelectronic Technology and IT (informationtechnology), which will be a supplement and support for the application ofnanodevice.Both optical and electrical properties on materials are related to meltingmechanism, they will be significant difference as size of materials decreases tonanometer size range.One of such material properties is the dielectric constantε. It is aconstant with bulk, and change with size when the size turns into nano range. Themodification ofεaffects the Coulomb interaction among electrons, which leads to thevariation of the activation (electron-hole pair) energies and thus would significantlychange the optical absorption and transport properties of semiconductor devices.Thus,the size dependence of ε has attracted considerable interest both experimentally andtheoretically.Phase change phenomena exists in industrial manufacture, electronic informationand so on all the time, such as heat treatment on devices, phase-changed opic, battery,they all need to live through phase change process. So, the solidition becomes ahotspot for researchers. On solidition, nucleation mechanism should be consideredprimarily. Nucleation rate determines the speed from crystalline to noncrystalline, andrelates to the application of electronic technology. So, it is vitally necessary to predictthe nucleation rate, which is important to the development and application on newmaterials.As the advancement of technology, ultra-large scale integration (ULSI) becamevitally necessary to our daily life. Devices trend towords miniaturization, the failureof Cu interconnection becomes a major source from the ULSI failure. Cuinterconnecton takes the place of Al interconnection and Al(Cu) interconnection forits high electrical resistivity and powerful ability on electromigration resistance. Toimprove device performance and reduce power consumption for each technologynode, a steady reduction of the wiring capacitance is essential.At present, the highdielectric constant on dielectric barrier limits the improvement on chips. For65nmnode, the dielectric constant is7for the traditional SiN dielectric barrier which goesbeyond the size of node, so the materials change to SiCN:H with dielectric constant being5to achieve the preparation. If smaller node being preparation, such as the45nm node, the dielectric barrier thickness is still kept at40nm which requires dielectricconstance being4. In the same way, the32nm node with dielectric constant beingless than3.5is limited by the high k value of the dielectric barrier.For the demands ofdevices’ miniaturization, a further reduction of k value is necessary.The preparation ofa-SiC:H filmintroducing pores in the films can solve this problem, which not onlyfurther decreases the value of dielectric constant, but also decreases the electricalresistivity.Nevertheless, reducing the density of a-SiC:H film will sacrifice the barrierproperties and lead to other reliability issues. Therefore, solving the problem ofreliability for Cu interconnecton is vitally necessary, and will be the base to researchand develop new materials.To improve the stability of Cu internection, the gooddoping at the interfaces is required which can enhance the interfacial stability andbonding strength of Cu interconnection. SAB (self-aligned barriers) technology isused to improve the reliability and to minimize overlap capacitance, and it also meetthe reqirement for miniaturization.In this paper, the models for size and interface effects on several thermodyanmicparameters of low dimension materials are set up in terms of thermal and dynaictheoretical models. These simple and unified models free of adjustable parameterswith full size rage,the parameters within the models have clear physical meaning. Themodels grow out of nature of nanomaterials (high surface (interface)\volume), andform the simple and unified equations. The hole contents are listed below:1. The dielectric constant of several dimension of nanomaterials were investedby the thermol and dynamic theoretical models. Size dependent and interfacedependent dielectric constant was established, without any adjustable parameter.These models predict a trend of different materials with low dimension with drop ofsize. On the base, the size and interface dependent of dielectric constant ofsemiconductor of low dimension, organic particles, H2O and chemical compoundswere discussed.2. To improve the technology of phase transition storage, nanomaterials forphase change memory (PCM) were discussed, the size dependent crystallization activation energy and amporphous nucleation rate of nanowires were set up. Themodels describe the course of crystallization which the atoms on the suface play adoninant role.3. According to Fick’s first law, Fick’s second law,and the traditional Arrheniusrelationship,the size and temperature dependent of the critical diffusion time isestablished, The working life of CuSiN multi-layer films is predicted by the models,;based on the traditional thermodynamics and dynamic theories, the models of sizedependent of the thermal expansion coefficient and the size isestablished,and thethermal stablity is verified. It is proved that CuSiN multi-films not only possess highworking life, but evidently improve the interface stability as barriers for Cuinternection. |
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