1,721,075 research outputs found
Effect of interfacial condition on electromigration for narrow and wide copper interconnects
No full text[[abstract]]The sub-micron damascene interconnects, electromigration is mainly due to the diffusion at the interfaces of Cu with liner or dielectric capping layer. Many reports have shown that Cu/capping dielectric is the dominant interface. Experiments were performed to study the effect of the interfacial conditions of Cu/capping dielectric material on electromigration for narrow and wide Cu lines. The results revealed significant differences in electromigration behavior of via-fed upper and lower layer damascene test structures. For upper layer test structure, the capping layer and plasma surface treatment significantly dominated EM performance for different line width structures. In the case of lower layer test structure, the electromigration time to failure was found to be influenced by the capping layer and via process, and it remained unaffected by the plasma surface treatment for the narrow Cu line. For the wide line width (3X), electromigration performance was influenced by the current crowding on via-bottom.[[note]]SC
Effect of inter-level dielectrics on electromigration in damascene copper interconnect
No full text[[abstract]]The impact of dielectric materials on the reliability of advanced copper (Cu) interconnect is of growing importance. The effect of barrier dielectrics and low-k materials of Inter-Level Dielectric (ILD) on the electromigration (EM) in the line and via-line structure of dual-damascene Cu interconnects was analyzed. The resulting electromigration behavior can then be attributed to Cu barrier layer or low-k dielectrics, depending on the test structure. The SiN barrier layer showed a better electromigration endurance compared to SiC barrier layer for narrow Cu line structure. We had also observed that the carbon-doped oxide (CDO) low-k samples had a higher drift velocity, which results in less electromigration endurance on the via-line structure compared to fluorosilicate glass (FSG). (c) 2005 Elsevier B.V. All rights reserved.[[note]]SC
Extraction of effective dielectric constants and the effect of process damage of low-k dielectrics for advanced interconnects
No full text[[abstract]]In this paper, the line-to-line parasitic capacitance of an advanced interconnects with a low-k dielectric (k < 3.0) was extracted by electrical measurement on comb-serpentine structures with various spacing. The empirical values are higher than the prediction from the filed solver, especially in the small geometries. A model was derived based on the damage of low-k dielectric during processing, which causes the increase of the dielectric constant. Then, the effective dielectric constant was evaluated by both simulation and theoretical models. The k value of damage zone was determined from blanket wafer by mercury probe after oxygen plasma treatment. Good agreement was obtained after we modified the simulation structure to include the damage zone. Especially, the concept of low-k damage due to plasma treatment was characterized for the first time. Thus, it is possible to use this model in the future study, such as the porous low-k in 65 nm or even 45 nm generations. (c) 2006 Elsevier B.V All rights reserved.[[note]]SC
Moisture effect on electromigration characteristics for copper dual damascene interconnection
No full text[[abstract]]The influence of moisture on Cu line electromigration (EM) behavior of dual damascene interconnection is reported. The authors have found that moisture has a negative influence on EM behavior, but it depends on the seal-ring structure located along the peripheral of the test pattern. The reduced Cu lifetime, observed for tested samples without seal-ring structure, was due to lateral moisture penetration. Lateral moisture diffusion was considered an effective mechanism for deteriorating the Cu interface during the die-sawing processing for structures without seal-ring layout. As a result, the seal-ring layout is effective and essential in Cu/low-dielectric (low-k) material integrity to prevent moisture penetration during the package procedures. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3501127][[note]]SC
Deposition cycle of atomic layer deposition HfO2 film: Effects on electrical performance and reliability
No full text[[abstract]]Varying thicknesses of the HfO2 films prepared by atomic layer deposition (ALD) were compared in terms of electrical properties and reliability. Scaling the physical thickness of the HfO2 dielectric did not increase the capacitance as expected due to the thicker interfacial SiOX layer obtained by the oxidation process used for thermal annealing. After thermal annealing, HfO2 crystallization increased with the thickness of HfO2 film, which then increases the dielectric constant for the bulk HfO2 film. The breakdown behaviors of the HfO2 gate dielectric film were not scaled to thickness, improved with HfO2 thickness until saturation. The reliability characteristics of the HfO2 dielectric under unipolar AC stressing were also evaluated. Dielectric breakdown failure time of unipolar AC stressing becomes longer in comparison to that stressed in constant voltage stress. As the thickness of the HfO2 dielectric increases, a larger lifetime enhancement is detected due to the effective charge de-trapping for thicker dielectrics under AC stressing. Crown Copyright (c) 2012 Published by Elsevier B.V. All rights reserved.[[note]]SC
Influence of temperature on the hydrogenated amorphous carbon films prepared by plasma-enhanced chemical vapor deposition
No full text[[abstract]]Hydrogenated amorphous carbon (a-C:H) films were deposited in a plasma-enhanced chemical vapor deposition (PECVD) system. The substrate temperature at deposition was found to have significant effects on the film stoichiometry, sp(2) phase, and optical properties. Raman spectroscopy reveals an increase in sp(2)-bonded carbon and a continual structure ordering of the sp(2) phase with increasing substrate temperature at deposition. Thermal desorption spectroscopy analysis revealed that the onset temperature of CH(4) effusion of PECVD a-C: H films increase with increasing substrate temperatures, implicating enhanced structural stability via elevating the substrate temperature at deposition. The extinction coefficient k measured from spectroscopic ellipsometry gradually increases with increasing substrate temperature at deposition, due possibly to the graphitization effect which decreases the optical gap resulting in higher k. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3497025][[note]]SC
Line-width dependency on electromigration performance for long and short copper interconnects
No full text[[abstract]]Experiments were performed to study the effect of metal line width on electromigration characteristics for Cu interconnects, and the results revealed completely different electromigration behavior for long and short metal lines. The extracted critical current density j(c) due to back stress effect can explain the electromigration width effect for long and short metal lines. For long metal lines, the electromigration times to failure were found to be increased with increasing the line width, and the critical current density j(c) is lower and slightly increased for the wider metal line. On the other hand, the electromigration failure time was observed to be inversely proportional to the line width in the case of short metal lines. Moreover, the back stress effect was decreased with increasing the line width, leading to the decreasing critical current density j(c). These observed effects are specific to Cu technology and can have major technological implications for electromigration assessment. (C) 2010 American Vacuum Society. [DOI: 10.1116/1.3484246][[note]]SC
Effect of fluorine flow and deposition temperature on physical characteristics and stability of fluorine-doped siloxane-based low-dielectric-constant material
No full text[[abstract]]The effects of SiF(4) flow rate and deposition temperature on the physical properties and stability of fluorine-doped organo-silica-glass (OFSG) films were investigated. The porosity of the as-deposited OFSG dielectrics declines as the flow rate of SiF(4) gas and the deposition temperature increase, increasing the dielectric constant. However, newly formed Si-F bonds have less electronic polarizability, reducing the dielectric constant. These traded-off properties yield a minimum dielectric constant of the OFSG film deposited at 250 degrees C with a SiF(4) flow rate of 100 SCCM (SCCM denotes cubic centimeter per minute at STP). The stability of Si-F bonds in the OFSG films is related to the deposition conditions. OFSG films deposited a higher SiF(4) flow rate (>400 SCCM) or a lower deposition temperature (< 300 degrees C) have lower thermal stability and are less well protected against moisture because of the instability of Si-F bonds. Therefore, more attention should be paid to the conditions for depositing fluorine-doped OFSG dielectrics.[[note]]SC
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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