Group IV Transition Metal (M = Zr, Hf) Precursors for High-κ Metal Oxide Thin Films.

This paper describes the synthesis of eight novel zirconium and hafnium complexes containing N-alkoxy carboxamidate-type ligands, as potential precursors for metal oxides and atomic layer deposition (ALD) for HfO2. A series of ligands, viz., N-ethoxy-2,2-dimethylpropanamide (edpaH), N-ethoxy-2-methylpropanamide (empaH), and N-methoxy-2,2-dimethylpropanamide (mdpaH), were used to afford complexes Zr(edpa)4 (1), Hf(edpa)4 (2), Zr(empa)4 (3), Hf(empa)4 (4), Zr(mdpa)4 (5), Hf(mdpa)4 (6), ZrCp(edpa)3 (7), and HfCp(edpa)3 (8). Thermogravimetric analysis curves assessed for the evaporation characteristics of complexes 1-8 revealed single-step weight losses with low residues, except for the mdpa-containing complexes. Single-crystal X-ray diffraction studies of 1, 2, 5, and 6 revealed that all the complexes have monomeric molecular structures, with the central metal ion surrounded by eight oxygen atoms from the four bidentate alkoxyalkoxide ligands. Among the complexes prepared, 8 exhibited a low melting point (64 °C), good volatility (1 Torr at 112 °C), high thermal stability, and excellent endurance over 6 weeks at 120 °C. Therefore, an ALD process for the growth of HfO2 was developed using HfCp(edpa)3 (8) as a novel precursor. Furthermore, the HfO2 film exhibited a low capacitance equivalent oxide thickness of ∼1.5 nm, with Jg as low as ∼3 × 10-4 A/cm2 at Vg -1 V in a metal-insulator-semiconductor capacitor (Au/HfO2/p-Si).

[1]  Zhigang Xiao,et al.  Comparison of Hafnium Dioxide and Zirconium Dioxide Grown by Plasma-Enhanced Atomic Layer Deposition for the Application of Electronic Materials , 2020, Crystals.

[2]  Jin-seong Park,et al.  Phase-controlled SnO2 and SnO growth by atomic layer deposition using Bis(N-ethoxy-2,2-dimethyl propanamido)tin precursor , 2019, Ceramics International.

[3]  B. Vilquin,et al.  Characterization of ferroelectric hafnium/zirconium oxide solid solutions deposited by reactive magnetron sputtering , 2019, Journal of Vacuum Science & Technology B.

[4]  B. Park,et al.  Synthesis of Indium Complexes for Thin Film Transistor Applications Bearing N ‐Alkoxy Carboxamide Ligands , 2018, ChemistrySelect.

[5]  J. Han,et al.  N‐Alkoxy Carboxamide Stabilized Tin(II) and Germanium(II) Complexes for Thin‐Film Applications , 2016 .

[6]  A. Vedda,et al.  Size-Dependent Luminescence in HfO2 Nanocrystals: Toward White Emission from Intrinsic Surface Defects , 2016 .

[7]  I. Oh,et al.  Effects of Cl-Based Ligand Structures on Atomic Layer Deposited HfO2 , 2016 .

[8]  Jeong Hwan Kim,et al.  Chemical structures and electrical properties of atomic layer deposited HfO2 thin films grown at an extremely low temperature (≤100 °C) using O3 as an oxygen source , 2014 .

[9]  Min Kyu Kim,et al.  Growth characteristics and electrical properties of Ta2O5 grown by thermal and O3-based atomic layer deposition on TiN substrates for metal–insulator–metal capacitor applications , 2013 .

[10]  T. Tseng,et al.  Growth, dielectric properties, and memory device applications of ZrO2 thin films , 2013 .

[11]  Jae Hyuck Jang,et al.  Dependence of optimized annealing temperature for tetragonal phase formation on the Si concentration of atomic-layer-deposited Hf-silicate film , 2011 .

[12]  Moon J. Kim,et al.  Characteristics of high-k Al2O3 dielectric using ozone-based atomic layer deposition for dual-gated graphene devices , 2010 .

[13]  K. Kukli,et al.  The Atomic Layer Deposition of HfO2 and ZrO2 using Advanced Metallocene Precursors and H2O as the Oxygen Source , 2008 .

[14]  Mircea Modreanu,et al.  Electrical, structural, and chemical properties of HfO2 films formed by electron beam evaporation , 2008 .

[15]  C. Musgrave,et al.  Atomic layer deposition of hafnium oxide from hafnium chloride and water. , 2008, Journal of the American Chemical Society.

[16]  Seokhoon Kim,et al.  Atomic Layer Deposition of HfO2 Thin Films on Ultrathin SiO2 Formed by Remote Plasma Oxidation , 2008 .

[17]  A. Kersch,et al.  The effect of dopants on the dielectric constant of HfO2 and ZrO2 from first principles , 2008 .

[18]  Jeong Hwan Kim,et al.  Effects of carbon residue in atomic layer deposited HfO2 films on their time-dependent dielectric breakdown reliability , 2007 .

[19]  K. Kukli,et al.  HfO2 Films Grown by ALD Using Cyclopentadienyl-Type Precursors and H2O or O3 as Oxygen Source , 2006 .

[20]  Lesley M. Smith,et al.  MOCVD and ALD of High-k Dielectric Oxides Using Alkoxide Precursors† , 2006 .

[21]  K. Kukli,et al.  Atomic layer deposition of hafnium dioxide thin films from hafnium tetrakis(dimethylamide) and water , 2005 .

[22]  Mikko Ritala,et al.  Controlled growth of HfO2 thin films by atomic layer deposition from cyclopentadienyl-type precursor and water , 2005 .

[23]  C. Hwang,et al.  Comparison of Properties of an Al2O3 Thin Layers Grown with Remote O2 Plasma, H2O , or O3 as Oxidants in an ALD Process for HfO2 Gate Dielectrics , 2005 .

[24]  Fu-Chien Chiu,et al.  Electrical conduction mechanisms of metal∕La2O3∕Si structure , 2005 .

[25]  B. E. White,et al.  Impact of Deposition and Annealing Temperature on Material and Electrical Characteristics of ALD HfO2 , 2004 .

[26]  K. Kukli,et al.  Properties of HfO2 Thin Films Grown by ALD from Hafnium tetrakis(ethylmethylamide) and Water , 2004 .

[27]  S. Park,et al.  Atomic layer deposition of hafnium oxide and hafnium silicate thin films using liquid precursors and ozone , 2004 .

[28]  K. Kukli,et al.  Atomic layer deposition of hafnium dioxide films using hafnium bis(2-butanolate)bis(1-methoxy-2-methyl-2-propanolate) and water , 2003 .

[29]  Ho-Kyu Kang,et al.  Comparison of HfO2 films grown by atomic layer deposition using HfCl4 and H2O or O3 as the oxidant , 2003 .

[30]  K. Kukli,et al.  Atomic layer deposition of hafnium dioxide films from 1-methoxy-2-methyl-2-propanolate complex of hafnium , 2003 .

[31]  Esther Kim,et al.  Atomic Layer Deposition of Hafnium and Zirconium Oxides Using Metal Amide Precursors , 2002 .

[32]  Chenming Hu,et al.  Direct tunneling leakage current and scalability of alternative gate dielectrics , 2002 .

[33]  Raghaw Rai,et al.  Thermodynamic stability of high-K dielectric metal oxides ZrO2 and HfO2 in contact with Si and SiO2 , 2002 .

[34]  R. Wallace,et al.  High-κ gate dielectrics: Current status and materials properties considerations , 2001 .

[35]  Donggun Park,et al.  Transistor characteristics with Ta/sub 2/O/sub 5/ gate dielectric , 1998, IEEE Electron Device Letters.

[36]  R. C. Fay.  Stereochemistry and molecular rearrangements of some six-, seven-, and eight-coordinate chelates of early transition metals , 1996 .

[37]  A. D. Ryon,et al.  The Vapor Pressures of Zirconium Tetrachloride and Hafnium Tetrachloride , 1958 .

[38]  Mikko Ritala,et al.  Growth and phase stabilization of HfO2 thin films by ALD using novel precursors , 2010 .