Films For Microelectronics Research Articles

Applications of Thin Films in Microelectronics

Due to their versatility, thin films, which can be formed through many different approaches, are being used in various applications in microelectronics[...]

The Influence of Argon Cluster Ion Bombardment on the Characteristics of AlN Films on Glass-Ceramics and Si Substrates.

In this paper, the influence of surface modification on the characteristics and properties of AlN thin films on Si and glass-ceramics substrates is investigated. The surface modification was made at various parameters of argon cluster ions. By using XRD and Raman spectroscopy, it was shown that the obtained AlN films have a hexagonal structure with a characteristic direction of texturing along the c axis and slight deviations from it. A comparison of the AlN surface morphology obtained by atomic force microscopy before and after cluster processing was demonstrated. This demonstrated that the cluster ions with low energy per atom (E/N = 10 eV/atom) have a high efficiency of surface smoothing. A decrease in the intensity of the Raman peaks and an increase in their full-width after bombardment with cluster ions were found, which may be caused by a change in the physicochemical state of the surface. The optical properties, the quality of the boundaries, and the distribution map of the thickness of the functional layer of AlN were investigated by the methods of spectral and spatial resolution ellipsometry. By using the cross-sectional SEM, the direction of crystallite texturing was demonstrated. The influence of argon cluster ion bombardment on the stoichiometry of samples was analyzed by EDX spectroscopy. The results obtained demonstrate the efficiency of the cluster ion smoothing of polycrystalline thin films for microelectronics, particularly when creating surface acoustic wave resonators.

Toward miniaturizing microelectronics using covalent organic framework dielectric

Toward miniaturizing microelectronics using covalent organic framework dielectric

Stepwise mechanism and H2O-assisted hydrolysis in atomic layer deposition of SiO2 without a catalyst.

Atomic layer deposition (ALD) is a powerful deposition technique for constructing uniform, conformal, and ultrathin films in microelectronics, photovoltaics, catalysis, energy storage, and conversion. The possible pathways for silicon dioxide (SiO2) ALD using silicon tetrachloride (SiCl4) and water (H2O) without a catalyst have been investigated by means of density functional theory calculations. The results show that the SiCl4 half-reaction is a rate-determining step of SiO2 ALD. It may proceed through a stepwise pathway, first forming a Si-O bond and then breaking Si-Cl/O-H bonds and forming a H-Cl bond. The H2O half-reaction may undergo hydrolysis and condensation processes, which are similar to conventional SiO2 chemical vapor deposition (CVD). In the H2O half-reaction, there are massive H2O molecules adsorbed on the surface, which can result in H2O-assisted hydrolysis of the Cl-terminated surface and accelerate the H2O half-reaction. These findings may be used to improve methods for the preparation of SiO2 ALD and H2O-based ALD of other oxides, such as Al2O3, TiO2, ZrO2, and HfO2.

Development of a templated approach to fabricate diamond patterns on various substrates.

We demonstrate a robust templated approach to pattern thin films of chemical vapor deposited nanocrystalline diamond grown from monodispersed nanodiamond (mdND) seeds. The method works on a range of substrates, and we herein demonstrate the method using silicon, aluminum nitride (AlN), and sapphire substrates. Patterns are defined using photo- and e-beam lithography, which are seeded with mdND colloids and subsequently introduced into microwave assisted chemical vapor deposition reactor to grow patterned nanocrystalline diamond films. In this study, we investigate various factors that affect the selective seeding of different substrates to create high quality diamond thin films, including mdND surface termination, zeta potential, surface treatment, and plasma cleaning. Although the electrostatic interaction between mdND colloids and substrates is the main process driving adherence, we found that chemical reaction (esterification) or hydrogen bonding can potentially dominate the seeding process. Leveraging the knowledge on these different interactions, we optimize fabrication protocols to eliminate unwanted diamond nucleation outside the patterned areas. Furthermore, we have achieved the deposition of patterned diamond films and arrays over a range of feature sizes. This study contributes to a comprehensive understanding of the mdND-substrate interaction that will enable the fabrication of integrated nanocrystalline diamond thin films for microelectronics, sensors, and tissue culturing applications.

Hybrid low dielectric constant thin films for microelectronics

The fabrication of future interconnects in integrated circuits requires insulators with decreasing dielectric constants in order to maintain or improve the electrical performance of such devices. This is achieved through the introduction of air in the form of porosity. However, such porous materials suffer from two major drawbacks: lower mechanical properties and decreasing plasma resistance. In this paper we discuss the design of novel low-k materials, the structure/porosity effect on plasma damage and emerging solutions envisioned to mitigate these issues.

(Invited) Metal Oxide Nano Film Characterization for CMP Optimization

This paper focuses on the planarization of metallic films in microelectronics manufacturing by CMP through investigation of metal oxide thin films forming as a result of the chemical component of the process. Tungsten planarization is discussed as a model to establish the role of metal oxide nano-films in achieving material removal through their formation characteristics during polishing. The findings indicate a protective oxide film formation on tungsten, which tends to nucleate at high concentrations of oxidizers and enables material removal through the interaction of nano-particles in the slurry with the surface oxide hillocks.

Controlling the microstructure of poly(vinylidene-fluoride) (PVDF) thin films for microelectronics

Download options Please wait... Article information DOI https://doi.org/10.1039/C3TC31774A Article type Paper Submitted 09 Sep 2013 Accepted 20 Sep 2013 First published 23 Sep 2013 This article is Open Access Download Citation J. Mater. Chem. C, 2013,1, 7695-7702 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Controlling the microstructure of poly(vinylidene-fluoride) (PVDF) thin films for microelectronics M. Li, I. Katsouras, C. Piliego, G. Glasser, I. Lieberwirth, P. W. M. Blom and D. M. de Leeuw, J. Mater. Chem. C, 2013, 1, 7695 DOI: 10.1039/C3TC31774A This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. You can use material from this article in other publications, without requesting further permission from the RSC, provided that the correct acknowledgement is given and it is not used for commercial purposes. To request permission to reproduce material from this article in a commercial publication, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party commercial publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Social activity Tweet Share Search articles by author Mengyuan Li Ilias Katsouras Claudia Piliego Gunnar Glasser Ingo Lieberwirth Paul W. M. Blom Dago M. de Leeuw

Surface Pseudorotation in Lewis-Base-Catalyzed Atomic Layer Deposition of SiO2: Static Transition State Search and Born–Oppenheimer Molecular Dynamics Simulation

Atomic layer deposition (ALD) is a novel deposition technique for constructing uniform, conformal, and ultrathin films in microelectronics, catalysis, energy storage, and conversion. The possible reaction pathways for the uncatalyzed and catalyzed ALD of silicon dioxide (SiO2) using SiCl4 and H2O have been investigated by density functional theory (DFT) calculations, combining static transition state searches with Born–Oppenheimer molecular dynamics (BOMD) simulations. In stepwise pathways of the uncatalyzed SiO2 ALD reaction, the rate-determining step is the Si–O bond formation accompanied by the rotation of SiCl4 with the activation free energy of 23.8 kcal/mol. The introduction of Lewis-base catalyst, pyridine or NH3, can reduce the activation free energy to 6.8 or 2.7 kcal/mol. The low energy barrier and flexible pentacoordinated intermediate facilitate the surface pseudorotation (SPR) pathway, which is similar to Berry pseudorotation (BPR) pathway of the trigonal bipyramid (TBP) molecules, such as Fe...

Adhesion Measurement Methods for Thin Films in Microelectronics

Diagnosing and improving adhesion of advanced packaging and thin films is an essential part of the research and development in microelectronics. In this paper, the four-point bend test and the double cantilever beam test among various adhesion measurement methods are reviewed.

Promising Application of Neodymium Oxide Nano Films in Microelectronics

Promising Application of Neodymium Oxide Nano Films in Microelectronics

Reliable Preparation of High Quality Superconducting Thin MgB2 Films for Application

Since the discovery of its superconductivity (J. Nagamatsu, N. Nakagawa, T. Muranka, et al., 2001, Nature, 410, 63), MgB2 attracts considerable attention. A number of groups have intensively tried to fabricate high-quality MgB2 films during the last years. However, the surface quality which is necessary for microelectronic device applications is still far from being achieved In this work we report the growth and the properties of high-quality films which are prepared in a two-step process: 1) deposition of the precursor films and 2) their annealing in Mg vapor with a specially designed, reusable reactor (C. B. Eom, et al., 2001, Nature, 411, 558). The films were grown on single crystal substrates of R-cut Al2O3 as well as of Al2O3 (100), (128° rot) LiNbO3 and MgO (100). The highest value of Tc = 39.4 K was observed for films deposited at 770 K on sapphire and MgO and annealed at 1120 K for one hour. Our method allows also the growth of high-Tc smooth films with high reproducibility and opens perspectives for the use of MgB2 films in microelectronics, especially for high-frequency applications.

A new generation of filtered arc sources for ultrathin top coats on magnetic hard disks

Filtered cathodic arc deposition is a promising candidate as an industrial PVD technology for the deposition of challenging films in microelectronics and microsystems. This technique has proven its superiority of depositing high quality films compared to conventional arc applications in numerous laboratory tests. In advanced sources, the number of droplets is reduced to less then 1 millionth corresponding to less than 1 μm size particle/cm 2, good enough for many advanced tool coatings but still insufficient for such highly demanding applications as the deposition of the top coat on a hard disk. In the present paper, recent improvements of the filtered high current pulsed arc (Φ-HCA) technique are described, resulting in a nearly complete droplet elimination to only a few 10-nm size particles/m 2. With the Φ-HCA-source, we are able to produce pinhole-free corrosion protective carbon films with thickness down to 1.7 nm. The thickness profile and uniformity on disk is adjustable by a magnetic field array. The deposition rate is 3–5 nm/s; therefore, the coating time is below one second per disk. The magnetic layer is left undamaged during the Φ-HCA deposition process. These aspects are very important for industrial disk production efficiency. Strong particle reduction due to a magnetic filter tube is confirmed by repeatable glide tests. In several important tests, we showed that the Φ-HCA source is capable of producing carbon layers within a realistic disk production environment with a yield of approximately 93%, which proved to be comparable to current industrial technology. Apart from the hard disk coating, the current Φ-HCA source is a carbon deposition technique with high potential for many other industrial applications, e.g. for acoustic sensors, selective ion-beam mask-layer and applications needing thermal conductivity layer, etc.

Silicalite-1/polymer films with low-k dielectric constants

Two-component films including nanosized silicalite-1 zeolite and acryl latex were deposited on silicon wafers via spin-coating approach. The first stage of the preparation included spin-on of as-synthesized or purified colloidal zeolite suspensions of silicalite-1 (MFI-type topology) nanoparticles with sizes of 30 and 60nm. After calcination of the zeolite films a layer of acryl latex was deposited. The porous silicalite-1/polymer films have high mechanical stability and dielectric constant in the range of 2.0–2.5. The porous nature, thickness and disorientation of the silicalite-1/polymer nanoparticles forming the films determine them as very promising low dielectric constant materials useful as insulating films in microelectronics.

Chemical solution deposition of PZT thin films for microelectronics

Research into chemical solution deposition (CSD) methods for ferroelectric thin films is oriented towards higher reliability and lower processing temperatures. In this paper several aspects of CSD PZT thin films related to processing are discussed. The reliability of PZT thin films is related to their chemical homogeneity, which is connected to the chemical homogeneity of the precursor solution. In our investigation we identified the problems of the chemical heterogeneity of PZT thin-film precursors caused by the high reactivity of Zr-alkoxide. By selective modification of the Zr starting compound with acetic acid, the overall chemical homogeneity of the films was increased, which resulted in a higher P r, a lower E c, a higher permittivity and lower losses in the films. By careful control of solution chemistry and annealing conditions, Ti-rich PZT and PLZT films were successfully processed at temperatures as low as 400°C. The crystallization of these films is characterized by rapid nucleation and rapid growth. In contrast, the Zr-rich PZT and PLZT compositions require a lead titanate (PT) seeding layer for further crystallization at a temperature of 400°C. The growth of the perovskite phase is diffusion controlled and, as a consequence, slow.

Theoretical Analysis of the Baking Process in Two Polymer/Solvent Systems: PMMA/Anisole and PMDA-ODA/NMP

Baking of polymer solutions is very important for preparing uniform thin films in microelectronics. In this study, a general theoretical analysis for baking was developed to predict the variation of polymer film thickness with baking temperature and time. The theoretical analysis result was justified by experimental results from poly(methyl methacrylate) (PMMA)/anisole and poly(pyromellitic dianhydride-co-4,4′-oxydianiline) (PMDA-ODA) amic acid/n-methyl pyrrolidone (NMP) systems. The theoretical analysis included a fixed boundary problem with a temperature-dependent-only diffusion coefficient, and moving boundary problems based on the diffusion coefficient from the Fujita-Doolittle equation and the Vrentas-Duda equation, respectively. The simulated results showed that the modeling equations based on the moving boundary problem with the Vrentas-Duda equation successfully predicted the variation of film thickness in comparison with the other two models. The diffusion coefficient (D), mass-transfer coefficient and Sherwood number (Sh) were used to explain the trend of the baking curves. In the cases of the PMMA/anisole system, the values of Sh increase significantly with increased baking time while the values of D show the opposite trend. This suggests that the baking mechanism has shifted from the evaporation-control mechanism to the diffusion-control mechanism. However, the values of Sh in the polyimide/NMP system are all larger than 15 because of the low diffusion coefficient of the solvent NMP. Hence, the transition of the evaporation-control to the diffusion-control no longer exists in the polymer/solvent system with a high-boiling-point solvent. The model based on the moving boundary problem with the Vrentas-Duda equation simulates a wide range of Sh values and results in higher accuracy than the other two models. © 2001 The Electrochemical Society. All rights reserved.

Electronic Structure of 1,5-Cyclooctadiene-copper(I)-hexafluoroacetylacetonate

The valence electronic structure of the compound 1,5-cyclooctadiene-copper(I)-hexafluoroacetylacetonate [(1,5-COD)Cu(hfac)], a prospective precursor for creation of thin copper films for microelectronics, has been investigated by ultraviolet photoelectron (He I) and X-ray emission spectroscopy. Electronic interactions of the 1,5-COD ligand with the copper atom were revealed by comparing spectra of the complex and of free 1,5-COD. C Kα spectra indicated a significant decrease of π electron density in the double bonds of 1,5-COD with the coordination of this molecule to the copper atom. The spectral changes and features were interpreted using the results of density functional calculation on the molecules. The detailed analysis of the highest occupied molecular orbitals of (1,5-COD)Cu(hfac) was carried out to explain the relatively low values of first ionization potential and decomposition temperature for the complex.

(HFA)Cu . 1,5-COD as the prospective precursor for CVD-technologies : The electronic structure, thermodynamical properties and process of formation of thin copper films

The properties of (HFA)Cu.1,5-COD complex, being the prospective CVD-precursor for thin copper films for microelectronics, were investigated by UV (He I) photoelectron, X-ray fluorescent spectroscopy and mass-spectroscopy together with ab initio calculations in approximation of density functional theory. The detailed analysis of energy and structure of highest occupied MO's of (HFA)Cu.1,5-COD was carried out. The thermodynamical and kinetical parameters of thermolysis reaction for (HFA)Cu.1,5-COD were determined and discussed. The initial stages of growth of thin copper films on the basis of this precursor (Si 3 N 4 substrates) were studied by high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy.

Comparative ion yields by secondary ion mass spectrometry from microelectronic films

Secondary ion mass spectrometry (SIMS) is reported from multiple-element multiple-matrix ion implants. The implants include a thirteen element metal set and a six element gas set implanted into films of interest for microelectronics (silicon, silicides, wiring layers, liner metals, inorganic dielectrics, and polymer dielectrics.) Using these standards, this study performs a broad comparison of ion yields using a metric defined as the normalized useful yield. We find that the yield of K+ with O2+ primaries is constant for almost all matrices, in keeping with a concept of ion yield saturation. The yield of Cl− with Cs+ primaries approaches a yield saturation limit for titanium but the ion yield falls for materials with higher sputter yields, becoming 3.5× lower from copper. The variations in negative ion yields from matrix to matrix are much larger, with anomalies more pronounced, for weaker-yielding ions, becoming 50× for C− from Ti to Cu. In this article we document sets of ion implants, show some of the SIMS profiles, and note trends in ion yields and implications for SIMS analysis.

Electroless Silver and Silver with Tungsten Thin Films for Microelectronics and Microelectromechanical System Applications

In this study we present the results of electroless deposition of silver (Ag) and silver tungsten [Ag(W)] layers on Si, intended for application in microelectronics and microelectromechanical systems (MEMS) technology. Silver has excellent resistivity but its thin‐film properties and its vulnerability to corrosion may cause a problem. In this work we present a novel Ag(W) type of layer that has improved thin‐film properties, such as resistivity and surface roughness, and can serve as both barrier layer and capping layer for corrosion protection of the Ag thin films. The thin‐film composition was studied as a function of the deposition parameters. We found the presence of tungsten, up to 3.1 atom %, and oxygen, up to 8 atom %, in addition to the silver atoms. We also studied the thin‐film morphology using atomic force microscopy and scanning tunneling microscopy imaging of the surface after each process step. Finally, we discuss the possible mechanisms for the deposition of Ag(W). © 2000 The Electrochemical Society. All rights reserved.