Chemical Vapor Deposition

Cover image for Chemical Vapor Deposition

Special Issue: High-Permittivity Dielectric Oxides

March, 2006

Volume 12, Issue 2-3

Pages 75–193

Issue edited by: Tony Jones

    1. MOCVD and ALD of High-k Dielectric Oxides Using Alkoxide Precursors (pages 83–98)

      A. C. Jones, H. C. Aspinall, P. R. Chalker, R. J. Potter, T. D. Manning, Y. F. Loo, R. O'Kane, J. M. Gaskell and L. M. Smith

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200500023

      Review: Thin films of high-dielectric oxides (ZrO2, HfO2, lanthanide oxides) are currently under intensive investigation as alternatives to SiO2 in sub-0.1 μm CMOS technology. This article reviews the use of new metal alkoxides containing donor-functionalized alkoxide ligands for the MOCVD and ALD of a range of these materials. The crystal structure of [Hf(dmop)4] is shown in the Figure.

    2. AVD and ALD as Two Complementary Technology Solutions for Next Generation Dielectric and Conductive Thin-Film Processing (pages 99–108)

      M. Schumacher, P. K. Baumann and T. Seidel

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200500027

      Two complementary advanced deposition technologies for next generation semiconductor devices are described: Atomic vapor deposition (AVD), a special MOCVD process mode, and atomic layer deposition (ALD). The operational principles and deposition results are described for a wide range of dielectric and conductive materials. Issues such as gas-phase saturation of precursors, stoichiometric control combined with deposition rate of films, and step coverage of trenches are considered.

    3. An MOCVD Approach to High-k Praseodymium-Based Films (pages 109–124)

      R. Lo Nigro, G. Malandrino, R. G. Toro and I. L. Fragalà

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200500382

      A description of the different CVD approaches to fabricating praseodymium oxide and silicate high-k films is presented. Special emphasis is placed upon the fabrication of Pr2O3 films through chemical techniques such as thermal CVD, liquid-injection CVD, and ALD. An overview of both the achievements and challenges has been given from different points of view, from the most suitable precursors to the most intriguing issues of thin-film fabrication and their stability on silicon substrates.

    4. Cyclic Atomic Layer Deposition of Hafnium Aluminate Thin Films Using Tetrakis(diethylamido)hafnium, Trimethyl Aluminum, and Water (pages 125–129)

      S.-H. Kim and S.-W. Rhee

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506371

      Hf-aluminate thin films have been deposited at 225 °C by cyclic atomic layer deposition of HfO2 and Al2O3 with tetrakis(diethylamido)hafnium, trimethyl aluminum, and H2O. The multicomponent thin films are formed by switching between alumina and hafnia deposition cycles, and the chemical composition of the film was controlled by adjusting the number of cycles of each oxide. The properties of film were analyzed by ICP-AES, XRD, and XPS.

    5. HfO2 and Hf1–xSixO2 Thin Films Grown by Metal-Organic CVD Using Tetrakis(diethylamido)hafnium (pages 130–135)

      Y. Ohshita, A. Ogura, M. Ishikawa, T. Kada, A. Hoshino, T. Suzuki, H. Machida and K. Soai

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506372

      Polycrystalline HfO2 films with few residual impurities and good step coverage can be deposited by using Hf(NEt2)4 as a Hf precursor. Hf(NEt2)4 is liquid at room temperature and has high vapor pressure. By injecting (NEt2)3SiH, Si(NCO)4, or Si(OEt)4 during HfO2 CVD, amorphous Hf1–xSixIO2 films can obtained. The amount of residual impurities is extremely reduced when Si(OEt)4 is used as the silicon precursor.

    6. MOCVD of Single-Axis c-Oriented Strontium Bismuth Titanate Thin Films and Their Electrical Properties (pages 136–142)

      K. Takahashi, M. Suzuki, T. Oikawa, T. Kojima, T. Watanabe and H. Funakubo

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506373

      SrBi4Ti4O15 films have been deposited on Pt-coated Si substrates by MOCVD using Sr(O2C11H19)2(C8H23N5)2, Bi(CH3)3, and Ti(O·i-C3H7)4 precursors. SrBi4Ti4O15 films with perfect single-axis c-orientation along the surface normal direction are obtained by inserting 100c-self-oriented LaNiO3 conductive buffer layers as an interfacial template on (111)Pt-layers. These films are degradation free in terms of dielectric constant against a decrease of film thickness down to 30 nm.

    7. Atomic Layer Deposition, Characterization, and Dielectric Properties of HfO2/SiO2 Nanolaminates and Comparisons with Their Homogeneous Mixtures (pages 143–150)

      L. Zhong, W. L. Daniel, Z. Zhang, S. A. Campbell and W. L. Gladfelter

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506375

      Nanolaminates of HfO2 and SiO2 have been prepared using ALD methods. Successive exposure of substrates maintained at 120 or 160 °C to N2 flows containing Hf(NO3)4 and (tBuO)3SiOH led to typical bilayer spacings of 2.1 nm. Combining Hf(NO3)4/(tBuO)3SiOH ALD with ALD cycles involving Hf(NO3)4 and H2O allowed systematic variation of the HfO2 thickness within the nanolaminate structure, providing an approach towards controlling the dielectric constant of the films. The nanolaminate structure inhibited the crystallization of the HfO2 in post-deposition annealing treatments.

    8. Atomic Layer Deposition of Praseodymium Aluminum Oxide for Electrical Applications (pages 152–157)

      P. de Rouffignac and R. G. Gordon

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506377

      Praseodymium aluminum oxide (PAO) thin films have been grown by ALD from a new precursor, tris(N,N′-diisopropylacetamidinato) praseodymium (Pr(amd)3), trimethylaluminum and water. Smooth, amorphous films can be deposited over a wide ALD window (225–325 °C), with nitrogen and carbon impurity levels below the detection limits of RBS. The permittivity of Pr1.15Al0.85O3 was 18, and all annealed films displayed very low leakage currents compared to other high-k oxide films deposited using ALD.

    9. Atomic Layer Deposition and Properties of Lanthanum Oxide and Lanthanum-Aluminum Oxide Films (pages 158–164)

      K. Kukli, M. Ritala, V. Pore, M. Leskelä, T. Sajavaara, R. I. Hegde, D. C. Gilmer, P. J. Tobin, A. C. Jones and H. C. Aspinall

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506388

      Lanthanum oxide growth on glass and Si substrates has been investigated using lanthanum silylamide and water as precursors in a substrate temperature range of 150–250 °C. The effect of ALD pulse times and precursor evaporation temperature on the growth rate and refractive index has been studied. Amorphous lanthanum aluminum oxide films can be achieved with stoichiometry close to that of LaAlO3 at 225 °C from La[N(SiMe3)2]3, Al(CH3)3 and H2O.

    10. Atomic Layer Deposited High-κ Films and Their Role in Metal-Insulator-Metal Capacitors for Si RF/Analog Integrated Circuit Applications (pages 165–171)

      C. Zhu, B.-J. Cho and M.-F. Li

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506393

      ALD-fabricated HfO2/Al2O3 laminate-structured MIM capacitors give superior performance over sandwiched/stacked counterparts as both thin and thick dielectric films. These include low leakage-current behavior, good polarity-independent electrical characteristics, high breakdown electrical field (voltage) and long time-to-breakdown, while maintaining comparable capacitance density and voltage coefficients of capacitance. The advantages of the laminate-structure are mainly attributed to the alternate insertions of Al2O3 into bulk HfO2, which prevents crystallization of HfO2.

    11. MOCVD of ZrO2 and HfO2 Thin Films from Modified Monomeric Precursors (pages 172–180)

      U. Patil, R. Thomas, A. Milanov, R. Bhakta, P. Ehrhart, R. Waser, R. Becker, H.-W. Becker, M. Winter, K. Merz, R. A. Fischer and A. Devi

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506394

      Monomeric, low-melting-point, volatile mixed tert-butoxide/β-ketoester complexes of Zr and Hf have been synthesized and characterized. The application of these precursors for low-temperature deposition of ZrO2 and HfO2 thin films by MOCVD has been demonstrated. [Zr(OBut)2(tbaoac)2], which was additionally tested in a liquid-injection MOCVD production tool, resulted in high-quality ZrO2 films displaying good electrical properties that show promise for technological applications.

    12. Effect of Oxidant on Downstream Microwave Plasma-Enhanced CVD of Hafnium Oxynitride Films (pages 181–186)

      Q. Luo, D. W. Hess and W. S. Rees Jr.

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506440

      Hafnium oxynitride films are deposited by downstream microwave plasma-enhanced CVD (DMPECVD). The effects of plasma-activated oxidants on the morphology, composition, and electrical properties of deposited dielectric films are studied. Films deposited using DMPECVD have amorphous morphologies, and contain more interstitial oxygen atoms that degrade the electrical properties of films than films deposited using metal-organic (MO)CVD.

    13. Growth by Liquid-Injection MOCVD and Properties of HfO2 Films for Microelectronic Applications (pages 187–192)

      C. Dubourdieu, E. Rauwel, C. Millon, P. Chaudouët, F. Ducroquet, N. Rochat, S. Rushworth and V. Cosnier

      Version of Record online: 22 MAR 2006 | DOI: 10.1002/cvde.200506397

      Thin films of HfO2 were deposited on (100) Si/SiO2 by liquid- injection MOCVD using [Hf(OtBu)2(mmp)2] precursor dissolved in octane. Films of thickness below 10 nm were studied by means of X-ray reflectometry, attenuated total reflection infrared spectroscopy (ATR) and AFM. Electrical properties were studied in MOS structures. A relative dielectric permittivity ϵr of 19 is obtained, consistent with that expected for monoclinic bulk HfO2. Rapid thermal annealing under ammonia permits reduction of fixed charges in the oxide as well as the interfacial charge density.