Tmix.= 10 min, tcomp.= 3 min,
Tmix. and comp= 190 °C
Tmix.= 10 min, tcomp.= 3 min, Tmix. and comp.= 190 °C
ABSTRACTS
The following is a list of the abstracts for papers which will be presented in the SECOND INTERNATIONAL SYMPOSIUM ON POLYMERS IN MICROELECTRONICS by presenting author. This list is updated continually to add abstracts as they become available and make appropriate corrections. This list may be conveniently searched by using the editor provided with most popular browsers (e.g. Microsoft Explorer, Netscape, ... etc.)
1) Natick Soldier Center, U.S. Army Soldier Biological and Chemical Command, Natick, MA 01760.
2) Center for Advanced Materials, University of Massachusetts Lowell, Lowell MA 01854
Biochemical Synthesis of a Water Soluble Conducting Molecular Complex of Conducting Polymers
Polyaniline is one of the most investigated conducting polymers over the past few decades. A considerable part of the research has been devoted to exploring methods to augment conductivity, processability and environmental compatibility. Polyelectrolyte assisted Horseradish Peroxidase (HRP) catalyzed polymerization of aniline has provided a route to synthesize water-soluble conducting polyaniline under mild conditions. Moreover synthetic enzymes such as hematin/polyethylene oxide (HEM-PEG) opened new avenues for the synthesis of novel water-soluble conductive polymers. We report the HRP and HEM-PEG catalyzed synthesis of a conducting water-soluble complex based on polyaniline, polypyrrole, PEDOT templeted on polystyrene sulfonate. The conductivity, UV-Vis, FTIR and TGA studies for these complexes indicate the presence of a thermally stable and electroactive polymers.
Use of High-resolution Ion Beam Techniques in the Analysis of Polymers In Microelectronic Devices
(Abstract not yet available)
Reliability Issue of Integrating Copper with Low k Polyimide Dielectric WITHDRAWN
With trends to shrinking in ULSI technologies, there is the need of faster performance and higher circuit density. As the device dimensions are scaled down, interconnect RC time delays and current density in the metal interconnections will increase. Copper, with its high electrical conductivity and melting temperature, provides smaller RC time delay and higher electromigration resistance that Al-based interconnections, so that Cu has been considered to replace current Al alloy interconnect materials. Low dielectric constant insulators, such as polyimide, are particularly attractive as an alternative intermetal dielectric to provide immediate performance improvement through reduction in capacitance. the use of polyimide as an alternative material to SiO2 in deep submicron offers several advantages, such as, low dielectric constant, good planarizing ability, low defect density and low cost processing. However, the usage of polyimide gives rise to many problems, such as, the sensitivity to moisture, sensitivity to variation in preparation procedures, ionic contamination and temperature rise due to low thermal conductivity.
This research focuses on the reliability issue of integrating copper with low-k dielectrics including polyimide. In this study, the poison effect, thermal characteristics, electromigration (EM) and thermal stress enhanced electromigration of Cu interconnects are investigated. The ease of planarization, low processing temperature and low dielectric constant are crucial for a good candidate as dielectric material for multilayer structure devices. the electromigration resistances of integrating copper with low-k dielectrics are discussed and mechanisms explored.
Evidence of Noble Metal Diffusion in Polymers at Room Temperature
(Abstract not yet available)
Development and Characterization of Polymers and Blend Composites Susceptible to act as a Current Collector
The ability of polymers to act as electrical insulator is the basis of their intensive application in the electric and electronic areas. But there are several cases where an electrical conductivity of polymeric materials is reached, in the case of electrostatic charge dissipation, the shielding of plastic boxes from the electromagnetic wave effects and recently as a conductive material. Consequently, material engineers have long sought to combine the versatility of polymers with the electrical properties of metals. The advantage is not only the ability to produce electrically conductive materials but also the ability to modify their electrical characteristics with large limits.
The carbon black (CB) is still the man product used in polymers to obtain electrical conductivity. In this work we were interested to develop a various composite materials based polymer and incompatible blend matrices. Mechanic and electric characterizations were carried out to localize the percolation threshold. The object is to develop conductive composite materials with low loadings of conductive filler. We studied the effect of concentration and type of filler in polymers and incompatible blends as matrices.
| |
| Fig 1 : Conductivity (s) Vs Wt % CB
in PP/PS blend (80/20) having
different thickness and in PP
Tmix.= 10 min, tcomp.= 3 min, Tmix. and comp= 190 °C |
Fig 2 : Conductivity (s) Vs Wt % CB
in PE/PP blend (80/20) having
different thickness and in PP
Tmix.= 10 min, tcomp.= 3 min, Tmix. and comp.= 190 °C |
Results shown the role of the incompatible blend to improve conductivity by more efficient distribution of the filler particles in the matrices. Composites Based PP/PS are more conductive than the composites based PE/PP.
Matrix presenting the adequate structure can improve the conductivity or same times to decrease the threshold of percolation. Percolation was detected at lower carbon concentrations in PP/PS system, than in The PE/PP and PP systems.
References:
1- D. M. BIGG, Journal of Rheology, vol. 28, N°5, (1984) 501-516
2- G. DUBOIS, Technique de l'ingénieur, A 3140, (1986).
3- G. GEUSKENS and col., Eur. Polym. J. vol. 23, N°12 (1987) 993-995.
4- F. GUBBELS and col., Macromolecules, Vol. 27, N°7 (1994) 1972-1974
5- C. DEL RIO and J. L. ACOSTA, Polymer, vol. 35, N°17 (1994) 3752-3757
6- Ph, LECLERE and Col., Mat. Res. Soc. Sym. Proc. vol. 474 (1997) 475-480
7- R. TAIPALUS, T. HARMI, K. FRIDRICH, Polymer Composites, vol. 21, N°3 (2000) 396-416
8- I. FISHER, J. ZOLTAN, A. SIEGMANN, Polymer Composites, vol. 21, N°3 (2000) 476-490.
Ink Jet Printing of Polymers for Electronic and Photonics Applications
Printing polymers and polymer solutions using ink jet technology is quickly moving from the research laboratory to the manufacturing floor. MicroFab Technologies has successfully applied ink jet printing technologies across a range of fields and applications including photonics, microelectronics, display manufacturing and energy systems. In this paper, we will focus on printing systems, polymer requirements, and applications.
Printing Systems
The precision printing system includes the printhead subsystem (printhead, fluid system, pneumatic subsystem and the drive electronics), the alignment /calibration subsystem, the maintenance subsystem, the precision motion system and the system controller. Printhead types and application specific configurations will be covered with respect to unique application requirements, material compatibility and manufacturing throughput. Single jet devices are acceptable for some applications, but most manufacturing applications require Array Printheads for high throughput.
Polymer Requirements
The key properties and requirements of both polymers and polymer solutions will be reviewed in this paper. Important properties of fluids for ink jet mechanics include their rheology, surface tension, and density. Practical application of polymer solutions by ink jet devices also requires that the solutions not dry so rapidly as to deposit solid materials around the orifice and that they form a stable meniscus between drop generations. If particle laden fluids are used, agglomerates no larger than 15% of the orifice diameter and stable suspensions are a must. Specific examples will be discussed.
Applications
A wide range of applications are emerging for this printing technology. They range from niche applications such as micro lenses for MEMS Optical Switches to killer applications in color polymer LED displays, organic electronics and RFID. The list below covers some of the application areas:
Microelectronics: dielectrics, passives, adhesives, underfills, conductors, organic FETs
Photonics interconnects (micro-lenses and waveguides) and packaging (adhesives, sealants)
Displays organic LEDs, hole transport layers, interconnects and spacers
Energy Systems photovoltaics and battery assembly & interconnect systems
Surface Activated Bonding of Clad Metal and Liquid Crystal Polymer at Low Temperature and Their Bonding Mechanism
(Abstract not yet available) WITHDRAWN
Molecular Modeling of Low k Dielectric Materials
Molecular modeling has been engaged to study property trends for spin-on low k dielectrics. A range of molecular modeling techniques have been used to predict the effect of material changes on dielectric constant, surface energy, adhesion, solubility, wet etch and clean resistance, and even pore generation, but molecular modeling has been particularly useful in the study of modulus. As the pore volume in these materials has increased in order to drive toward lower k, modulus has necessarily decreased. However, because modulus is an important property to understand as it relates to the survivability and reliability of the film during post-processing, we have found it necessary to understand the limitations of introducing such high volume fractions of voids. Although molecular techniques cannot simulate the bulk material, we have found that from studying the wall material and simulating the stress-strain curve of a single molecular pore we can develop adequate comparisons of material modulus. Trends can then be compared which tell us how the material construction affects the modulus. These changes have been validated by experimental results. In addition, by combining analysis techniques we can compare and monitor how material changes to affect modulus will effect other important properties such as dielectric constant and thermal stability.
S.T. Chen1, R. Dellaguardia1, B. Herbst2, and K. Kumar1
1) Semiconductor Research and Development Center; IBM Microelectronics, 2070 Route 52, Hopewell Junction, NY 12533
2) IBM T.J. Watson Research Center, Yorktown Heights, NY 10598
Developmental Integration of Porous SiLKTM
To meet stringent RC delay requirements for sub 0.1m BEOL interconnects, there has been a widespread evaluation of ULK materials (1.5<<2.2). A subset of these materials includes F-doped silica glass, and porous materials. However, with F-doped silica materials, concerns of F- migration at typical BEOL processing temperatures arise. With porous materials, the pore size, distribution, and interconnectivity also pose a concern. In this communication, we specifically report on the developmental progress of porous SiLKTM integration in BEOL interconnects. Porous SiLKTM did not show interconnectivity of pores. Additionally, there was a reduction in pore size and with each iteration.
1 IMEC, Kapeldreef 75,B-3001 Leuven, Belgium
2 K.U.Leuven, MTM, Kasteelpark Arenberg 44, B-3001 Leuven, Belgium
Characterisation of Ald Diffusion Barrier Growth on a Low-k Dielectric Polymer Surface
Atomic layer deposition (ALD) is a promising method for the growth of ultra-thin, conformal copper diffusion barriers such as WCN, TaN and TiN [1]. Barrier film growth can be divided into two regions, a transient regime where the growth rate increases with cycle number and a converged region where the growth rate is constant with cycle number [2]. The growth mechanism within the transient regime is strongly dependent on the nature of the substrate surface which controls the duration of the transient region and therefore determines the properties of the barrier. Our study focuses on the surface preparation and characterisation of SiLK*, an aromatic polymer which has promising potential as a low-k dielectric material. X-ray photoelectron spectroscopy (XPS) has been utilized for studying the surface composition of the polymer surface following different plasma treatments. Specific derivatization reactions allow the identification of surface groups which act as active sites for ALD. Assuming that higher metal content reflects more efficient growth of the barrier, successful creation of active sites on the polymer surface by plasma treatment is assessed by growth of a very thin ALD barrier and measuring the resulting metal content using Rutherford back scattering (RBS). Improved growth of the barrier is confirmed by TEM measurements. In particular, island-type growth is observed in the case of non-modified substrates while the more desirable layer-by-layer growth is observed for the plasma treated samples. These observations are supported by AFM measurements and can be explained in terms of improved ALD precursor adsorption on the treated substrate surface.
*SILK® is Dow Chemical trademark
[1] S.Haukka, E.L.Lakomaa and T.Suntola, Adsorption and its applications in Industry and Enviromental Protection Studies in Surface Science and Catalysis, Vol. 120.(1998)
[2] J.-W. Lim, H.-S. Park, and S.-W. Kang, J. Electrochem. Soc.148 (2001) C403.
1) Department of Chemical Engineering, National University of Singapore, 10 Kent Ridge Crescent, SINGAPORE 119260
2) Department of Mechanical Engineering, National University of Singapore, Engineering Drive 2, SINGAPORE 119260
Electroless Metallization of Modified Silicon Surfaces
Electroless plating of copper and other metals via a one-step, tin-free activation process was carried out effectively on three types of modified Si(100) surfaces. Plasma polymerization and deposition of 4-vinylpyridine (4VP) was carried out on the Ar plasma-pretreated Si(100) surface. The second type of surface was prepared by etching of the Si(100) surface with HF to produce the hydrogen-terminated silicon surface (the H-Si(100) surface). The H-Si(100) surface was further functionalized via UV-induced reactive coupling of the vinylpyridines. Finally, the SiLKÒ-coated Si(100) surface (the SiLKÒ-Si surface) was functionalized by UV-induced graft copolymerization with 4VP, 1-vinylimidazole and viologen. The functionalized silicon and SiLKÒ-Si surfaces provided chemisorption sites for the palladium species, without the need for prior sensitization by SnCl2, during the electroless metal plating process. The functional grafts also served as the adhesion promotion layer and diffusion barrier for the electrolessly deposited copper.
Seon Jeong Kim, Sang Jun Park, In Young Kim and Sun I. Kim; Dept. of Biomedical Engineering, Hanyang University, Sungdong P.O. Box 55, Seoul 133-605, KOREA
Characteristics of Electric Stimuli Response of Poly(vinyl alcohol)/
Chitosan IPN Hydrogel in NaCl Solutions
Interpenetrating polymer network (IPN) hydrogel composed of poly(vinyl alcohol) (PVA) and chitosan exhibited electrical-sensitive behavior. The PVA/chitosan IPN hydrogel was synthesized by ultraviolet (UV) irradiation method for the application to several biomedical and industrial field. The swelling behavior of PVA/chitosan IPN hydrogel was studied by immersion of the gel in NaCl aqueous solutions at various concentrations. The swelling ratio decreased with increasing concentration of NaCl solution. The stimuli response of the IPN hydrogel in electric fields was also investigated. When a swollen PVA/chitosan IPN was placed between a pair of electrodes, the IPN exhibited bending behavior upon the applied electric field. The bending angle and the bending speed of the PVA/chitosan IPN increased with increasing applied voltage and concentration of NaCl aqueous solution. The PVA/chitosan IPN also showed stepwise bending behavior depending on the electric stimulus. In addition, thermal properties of PVA/chitosan IPN were investigated by differential scanning calorimetry (DSC) and dielectric analysis (DEA).
Ultraviolet Radiation Curing Technology for Encapsulation of Led Lamps by Epoxy Resins
(Abstract not yet available)
R. N. Kumar ,Lim Yoke Keem and Ng Chee Mang; School of Industrial Technology, Unbiversiti Sains Malaysia, 11800 Pulau Pinang, Malaysia.
Development of Ultraviolet Curable Encapsulating Epoxy Resin Formulations for the Production of Led's
(Abstract not yet available)
1) Laboratorio Superfici ed Interfasi - Catania Ricerche, c/o STMicroelectronics, Stradale Primosole 50, 95121 Catania, ITALY
2) STMicroelectronics, Stradale Primosole 50, 95121 Catania, ITALY
3) Toshiba Chemical Corporation, Hankyu Express Building, 3-9, 3-chome, Shimbashi, Minato-ku, Tokyo 105-0004, JAPAN
4) Dipartimento di Scienze Chimiche Università di Catania, Viale A.Doria 6, 95125 Catania ITALY
Chemistry of Green Encapsulating Molding Compounds at Interfaces with Other Materials in Electronic Devices
Recently new formulated halogen and antimony free molding compounds, the so called "Green materials", gained more and more interest toward the microelectronics industry. These materials are designed to meet flammability requirements with the necessity to reduce the presence of toxic elements in the electronic packeges and, consequently, in the environment. On the other hand, as a consequence of halogens elimination from the formulation, an increase of the overall electronic package reliability is also expected. It is well demonstrated that halogens and other ionic impurities are responsible for metal corrosion under bias and humidity-temperature conditions.
This paper reports a study of the interface chemistry and adhesion of two epoxy - phenolic molding compounds, "green" and, for comparison, "conventional" respectively, to the most relevant surfaces like copper oxides-hydroxides and aluminium oxide-hydroxide. The study was carried out on laboratory specimen by comparison of delamination (Scanning Acoustic Microscopy) and pull strength data with the interface chemistry studied by ESCA [1]. The chemistry of these interfaces was correlated to the behaviour of real electronic devices, assembled using the two compounds, under reliability tests.
REFERENCE
1) A. Scandurra, R. Zafarana, Y. Tenya, and S.Pignataro, "Study of Adhesion Failure due to Molding Compound Additives at Chip Surface in Electronic Devices", J. of Adhesion Science and Technology, Vol. 15, N. 9, pp. 1039-1053 (2001).
Conductive Rubber for Electronic Applications
A one-phase conductive rubber has been recently developed by using polypyrrole to crosslik poly(styeren-butadiene-styrene) elastomer. The maximum eleongation of the conductive rubber is 140% and its surface conductivity is 0.4 S/cm. A highly anisotropy in electricity has been obtained by stretching the rubber. This is the first discovery for a conductive rubber contains only one phase.
Materials and Patterning Techniques for Flexible and Nanoscale Electronics
Organic and molecular materials hold great promise for the future of electronics, photonics and nanotechnology. New additive printing and lamination techniques can be used directly with these classes of 'soft' materials to build electronic devices with near-molecular dimensions: the electrical contacts in both cases are formed at ambient conditions that do not degrade or disrupt the often chemically and mechanically fragile organics. This talk describes these methods and their use in fabricating organic transistors, circuits that incorporate them and prototype systems, such as electronic paperlike displays, that illustrate some of their potential applications.
Adhesion of PI Coated Optical Fibre to PZT Substrates
The failure mechanism between Polyimide (PI) coated optical fibre joined to PZT substrate has been studied using fibre pullout and die shear tests. The die shear and fibre pullout tests are discussed together with an interpretation of joint strength in relation to the stress distribution measurements. In the fibre pullout test, in particular, it is shown that sample configuration affects the stress distribution which influences the measured joint strengths.
Furthermore, the role of surface contaminates on the adhesive bond of PI to PZT is highlighted. A range of Lewis-acid and Lewis-base chemicals have been used, as a chemical pre-treatment method, to remove the contaminants from the PI surface. Argon-Oxygen plasma is also used, as a physical pre-treatment method. The role of surface treatment on the joint strength and long term durability of the joint is described. Advantages and disadvantages of each method are highlighted.
It is shown, that a UV curable optical adhesive used provide better adhesion to the PZT than E-glass than PI.
1) Advanced Materials Processing and Analysis Center (AMPAC), Department of Mechanical, Materials, and Aerospace Engineering, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816
2) SiloQuest, Inc., 6901 TPC Boulevard, Suite 650, Orlando, FL 32822
3) School of Optics/CREOL, Department of Chemistry, University of Central Florida, 4000 Central Florida Boulevard, Orlando, FL 32816
Characterization of Polyurethane Pads for Chemical Mechanical Planarization (CMP) using XPS, SSIMS, AFM, SEM, and Polishing Performance
Chemical Mechanical Planarization (CMP) has emerged as a key technology for meeting the stringent requirements of the next generation microelectronic devices. Both industry and academia have made significant strides in CMP technology, but a complete understanding of the process does not exist. One important aspect of gaining this complete understanding is the characterization of the consumables, including the polyurethane polishing pads. Understanding the surface changes that occur in the manufacturing and use of these materials allows for their more efficient use and for the development of improved polymers with specific applications in mind.
The surface chemical structure, morphology, and mechanical response of these materials were investigated using various characterization techniques. X-ray photoelectron spectroscopy (XPS) and static secondary ion mass spectrometry (SSIMS) were used to map the changes in the surface chemistry of segmented polyurethanes due to exposure to chemical environments commonly found in the CMP process. Shifts in elemental binding energies due to changes in the ratio of rigid to flexible backbone segments at the surface are discernable using these techniques. Atomic force microscopy (AFM) and other scanning probe microscopy (SPM) techniques were used to further characterize the surface of known polyurethane bulk samples after chemical exposure. These techniques allow for correlation of morphological and mechanical response changes with surface chemistry changes found using XPS and SSIMS. Also, both scanning electron microscopy and energy dispersive spectroscopy have been used to further evaluate the pad morphology as a function of conditioning and polishing.
1) Department of Chemistry and Center for Materials Science and Engineering, Rochester Institute of Technology, Rochester, New York, 14623
2) Department of Physics, RIT, Rochester, New York, 14623
3) IBM Corporation, Microelectronics Division, Endicott, New York 13760
Adhesion of Copper to Poly(tetrafluoroethylene) Surfaces Modified with Vacuum UV Radiation
Teflon ® poly(tetrafluoroethylene) (PTFE) is an attractive material for high-performance electronic applications because of excellent thermal, chemical, electrical (low dielectric constant), and low surface energy properties. However, PTFE presents considerable challenges for adhesion and wettability when bonding to other materials.
Films of PTFE were modified with vacuum ultraviolet (VUV) radiation from 6.7 x 104 Pa He arc plasmas that were made to rotate inside of a graphite tube by the application of an auxiliary magnetic field. Photoetching was observed, as well as, surface modification that showed the following: (1) water contact angles that started to decrease in the wavelength region between 173 and 160 nm and continued to decrease with shorter wavelengths; (2) surface roughening; (3) defluorination of the surface with a slight increase in the atomic %C and formation of C-C bonds in the top 3-5 nm of the surface as detected by XPS analysis; and (4) incorporation of oxygen, presumably from reaction with oxygen in air. Results will be reported on the adhesion of copper, that was deposited by both sputtering and evaporation methods, to these modified PTFE surfaces.
______________________________________________________
* Corresponding author. Tel: 585-475-2047, Fax: 585-475-7800, E-mail: gatsch@rit.edu
® Teflon is a registered trademark of E. I. duPont De Nemours & Co., Wilmington, DE.
IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120
1) IMB T.J. Watson Research Center, Kitchawan Road, Yorktown, NY 10598
2) Washington State University, Pullman, WA 99164
Nanoporous, Low Dielectric Constant Organosilicate Materials Based on Inorganic/Organic Polymer Blends
Porous organosilicates useful as dielectric materials can be prepared by templating the vitrification of low molecular weight silsesquioxanes using highly branched, thermally labile macromolecules, which are subsequently removed in a thermal process to generate porosity. The process involves spin-coating the inorganic/organic hybrid followed by thermal curing to initiate vitrification of the matrix. The morphology is fixed during the formation of the nanoscopic hybrid and is maintained during pore generator (porogen) decomposition at elevated temperatures. This process generates controllable and stable morphologies where the void volume is determined by the porogen loading levels ranging from 0 to >70 weight %. The proper selection of materials parameters, e.g. molecular weight and end group functionality, produces very small, discrete pores, < 3 nm, at low porosities (< 30 %). At higher porogen loadings (> 30 %) the pore structure becomes interconnected. Within these two porosity regimes dielectric constants approaching 2.0 for the non-interconnected pore architecture and < 2.0 for interconnected porosities are readily obtained.
Polymers for 157 nm Resist Applications
(Abstract not yet available)
Characterization of Interface Fracture Toughness in Underfill Bonding Using Compact Mixed Mode Specimens
(Abstract not yet available)