Showing papers on "Hafnium published in 2001"

Semiconductor devices having metal layers as barrier layers on upper or lower electrodes of capacitors

Abstract: A method of forming a metal layer having excellent thermal and oxidation resistant characteristics using atomic layer deposition is provided. The metal layer includes a reactive metal (A), an element (B) for the amorphous combination between the reactive metal (A) and nitrogen (N), and nitrogen (N). The reactive metal (A) may be titanium (Ti), tantalum (Ta), tungsten (W), zirconium (Zr), hafnium (Hf), molybdenum (Mo) or niobium (Nb). The amorphous combination element (B) may be aluminum (Al), silicon (Si) or boron (B). The metal layer is formed by alternately injecting pulsed source gases for the elements (A, B and N) into a chamber according to atomic layer deposition to thereby alternately stack atomic layers. Accordingly, the composition ratio of a nitrogen compound (A—B—N) of the metal layer can be desirably adjusted just by appropriately determining the number of injection pulses of each source gas. According to the composition ratio, a desirable electrical conductivity and resistance of the metal layer can be accurately is obtained. The atomic layers are individually deposited, thereby realizing excellent step coverage even in a complex and compact region. A metal layer formed by atomic layer deposition can be employed as a barrier metal layer, a lower electrode or an upper electrode in a semiconductor device.

Methods of using atomic layer deposition to deposit a high dielectric constant material on a substrate

Abstract: Methods of forming hafnium oxide, zirconium oxide and nanolaminates of hafnium oxide and zirconium oxide are provided. These methods utilize atomic layer deposition techniques incorporating nitrate-based precursors, such as hafnium nitrate and zirconium nitrate. The use of these nitrate based precursors is well suited to forming high dielectric constant materials on hydrogen passivated silicon surfaces.

Physical and electrical characterization of Hafnium oxide and Hafnium silicate sputtered films

Abstract: Hafnium oxides and hafnium silicate films were investigated as a possible replacement for the SiO2 gate dielectric. Hafnium oxide films were formed by reactive sputtering from a single Hf oxide target in a predominantly Ar atmosphere containing small additions of oxygen. Hafnium silicates were made by adding a He-diluted silane gas for Si incorporation. By changing the silane gas flow, different Si atomic concentrations were incorporated into the Hf oxide films. Depositions were performed with the substrate held at temperatures of 22 °C and 500 °C. The chemical composition of the films was determined with nuclear techniques. Optical reflectivity was used to measure the optical band gap. The film morphology was investigated by transmission electron microscopy (TEM) and the electrical properties were measured with capacitance–voltage and current–voltage measurements using aluminum gate capacitors. TEM and electrical measurement showed that a SiO2 interfacial layer of about 3 nm formed at the Si interface du...

Novel gamma-phase of titanium metal at megabar pressures.

Abstract: Group IV transition metals titanium, zirconium, and hafnium are expected to transform from an ambient hexagonal close packed (hcp, alpha-phase) to a body centered cubic (bcc, beta-phase) at high pressures. This transition path is usually facilitated by the occurrence of an intermediate hexagonal phase (distorted bcc, omega-phase). The existence of a bcc phase in zirconium and hafnium at high pressures has been known for the past ten years; however, its occurrence in titanium has been theoretically predicted but never observed. We report a novel unexpected transformation in titanium metal from an omega phase to an orthorhombic phase (distorted hcp, gamma-phase) at a pressure of 116+/-4 GPa.

Method for making a hafnium-based insulating film

Abstract: A hafnium-based dielectric layer, such as hafnium oxide (HfO2), is formed over a semiconductor substrate by flowing a hafnium-containing precursor of hafnium (Hf) and iodine (I) and an oxygen-containing precursor resulting in a high quality dielectric layer over the substrate. In one embodiment, the hafnium-containing precursor is Hafnium tetraiodide (HfI4). The two precursors may be applied simultaneously or alternately. The hafnium tetraiodide may be provided into a reaction chamber via sublimation or direct liquid injection.

Hafnium interdiffusion studies from hafnium silicate into silicon

Abstract: The interdiffusion of Hf and Si from high-κ gate dielectric candidate (HfO2)1−x(SiO2)x thin films deposited on Si (100) was studied using x-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, high resolution transmission electron microscopy, and Rutherford backscattering spectrometry in combination with chemical etching. After extreme rapid and conventional furnace thermal annealing treatments, Hf incorporation into Si is limited to less than 0.5–1 nm from the interface. Implications for high-κ gate dielectric applications are also discussed.

Method of fabricating a highly reliable gate oxide

Abstract: An ultra-thin gate oxide layer of hafnium oxide (HfO2) and a method of formation are disclosed. The ultra-thin gate oxide layer of hafnium oxide (HfO2) is formed by a two-step process. A thin hafnium (Hf) film is first formed by thermal evaporation at a low substrate temperature, after which the thin hafnium film is radically oxidized using a krypton/oxygen (Kr/O2) high-density plasma to form the ultra-thin gate oxide layer of hafnium oxide (HfO2). The ultra-thin gate oxide layer of hafnium oxide (HfO2) formed by the method of the present invention is thermally stable in contact with silicon and is resistive to impurity diffusion at the HfO2/silicon interface. The formation of the ultra-thin gate oxide layer of hafnium oxide (HfO2) eliminates the need for a diffusion barrier layer, allows thickness uniformity of the field oxide on the isolation regions and, more importantly, preserves the atomically smooth surface of the silicon substrate.

Atomic scale effects of zirconium and hafnium incorporation at a model silicon/silicate interface by first principles calculations

Abstract: First principles calculations aimed at quantifying the effects of zirconium and hafnium incorporation at a model silicon/silicate interface have been performed. The tetrahedral bonding character of silicates allows useful comparisons as well as important new distinctions to be drawn with the familiar Si/SiO/sub 2/ system. The calculated energy cost of forming (Zr,Hf)-Si bonds suggests that SiO/sub 2/-like bonding is energetically favored over silicide-like bonding at the Si interface. The calculations also suggest that the volume strain associated with Zr or Hf incorporation may lead to increased stress, both in the bulk oxide and in the interfacial transition region.

Corrosion resistive gmr and mtj sensors

Abstract: Spin valve (SV) and magnetic tunnel junction (MTJ) magnetoresistive sensors are provided having magnetic layers with improved corrosion resistive properties. The SV and MTJ sensors include antiparallel (AP)-pinned layers formed of Co—Fe—X, where X is niobium (Nb), hafnium (Hf) or a mixture niobium and hafnium (NbHf) and laminated free layers formed of Co—Fe—X layers and Ni—Fe—Y layers, where Y is tantalum (Ta) or chromium (Cr). The addition of 5 to 10 atomic wt. % of Nb, Hf or NbHf to Co—Fe and 5 to 10 atomic wt. % Ta or Cr to Ni—Fe improves corrosion resistance by a self-passivation effect of the these metals. Addition of these metals to the magnetic layers reduces grain size of the layers resulting in increased electrical resistance leading to reduced sense current shunting and increased deltaR/R.

Process for forming hafnium oxide films

Abstract: A process for forming a hafnium oxide-containing film on a substrate such as silicon that includes introducing an anhydrous hafnium nitrate-containing precursor into a reactor containing the substrate, and converting the precursor into the hafnium oxide-containing film on the substrate by chemical vapor deposition

High purity zirconium or hafnium, sputtering target comprising the high purity zirconium or hafnium and thin film formed using the target, and method for producing high purity zirconium or hafnium and method for producing powder of high purity zirconium or hafnium

Abstract: A high purity zirconium or hafnium which is extremely reduced in the contents of an alkali metal such as Na or K, a radioactive element such as U or Th, a transition metal or heavy metal or high melting point metal such as Fe, Ni, Co, Cr, Cu, Mo, Ta or V, and a gas forming element such as C or O; and a method for producing a high purity zirconium or hafnium which allows the production thereof at a low cost; and a method for producing a powder of high purity zirconium or hafnium with safety and at a low cost which comprises using a hydrogenated high purity zirconium or hafnium as a material. The high purity zirconium or hafnium is greatly reduced in the contents of impurities which are obstacles to assurance of operational functions of a semiconductor.

Doped zirconia or zirconia-like dielectric film transistor structure, and method of depositing the same

Abstract: PROBLEM TO BE SOLVED: To provide a high-k dielectric material, having electron affinity whose electrical characteristics are controlled by further adding elements to an existing high-k dielectric material. SOLUTION: This thin film has high dielectric constant with respect to silicon dioxide and is a high dielectric constant film formed by containing a) doping metal, b) metal selected from among a group consisting of zirconium(Zr) and hafnium(Hf) and c) oxygen. COPYRIGHT: (C)2002,JPO

Structural modifications of hafnium oxide films prepared by ion beam assisted deposition under high energy oxygen irradiation

Abstract: This work deals with high-energy ion beam assisted deposition (IBAD) of HfO 2 on Si(100) substrates. Hafnium vapor was generated from a metallic hafnium target with simultaneous bombardment with oxygen ions accelerated at energies of 1–20 keV, a much higher energy regime than in other IBAD works. The transport ratio (TR), defined as the ratio between the hafnium arrival rate and the oxygen ion dose, was in the range of 0.5–10. The substrate was not heated during deposition. The films’ structure and properties were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), electron probe micro-analysis (EPMA), and Knoop microhardness. Significant structural modifications were observed with parameter variation. Films consisting of tetragonal and cubic structure or mixtures of these with the monoclinic phase were obtained. To the authors’ knowledge this is the first report of non-monoclinic phases observed in IBAD films. Measurements of film stoichiometry show that the films are oxygen deficient; the Hf/O ratio appears to be approximately 1:1.5 despite variations in TR. At 20 keV acceleration energy the microhardness increased linearly with TR, reaching a maximum of 25 GPa at a TR value of 10. The high hardness is associated with the new tetragonal phase.

CVD aluminiding process for producing a modified platinum aluminide bond coat for improved high temperature performance

Abstract: A method of depositing by chemical vapor deposition a modified platinum aluminide diffusion coating onto a superalloy substrate comprising the steps of applying a layer of a platinum group metal to the superalloy substrate; passing an externally generated aluminum halide gas through an internal gas generator which is integral with a retort, the internal gas generator generating a modified halide gas; and co-depositing aluminum and modifier onto the superalloy substrate In one form, the modified halide gas is hafnium chloride and the modifier is hafnium with the modified platinum aluminum bond coat comprising a single phase additive layer of platinum aluminide with at least about 05 percent hafnium by weight percent and about 1 to about 15 weight percent of hafnium in the boundary between a diffusion layer and the additive layer The bond coat produced by this method is also claimed

Synthesis and properties of axially substituted zirconium(IV) and hafnium(IV) phthalocyanines with organic ligands

Abstract: Water-soluble phthalocyaninato zirconium(IV) and hafnium(IV) complexes have been synthesized for the first time. An increased solubility in comparison to PcZrCl2 and PcHfCl2 was caused by the introduction of gallic, 1,8-dihydroxynaphthalene-3,6-disulfonic (chromotropic), and 5-sulfosalicylic acids in the axial position. The new compounds were characterized by 1H NMR, IR, UV-vis and elemental analysis.

Device having a high dielectric constant material and a method of manufacture thereof

Abstract: The present invention provides a method of manufacturing a semiconductor device. The method includes depositing a metal oxide containing a dopant and having a high dielectric constant on a substrate; wherein the metal is aluminum or silicon and the dopant is zirconium or hafnium and etching the doped metal oxide with a plasma containing a halogenated compound.

Enthalpies of Mixing in Liquid Alloys of Copper with Hafnium

Abstract: Enthalpies of mixing of liquid alloys of copper with hafnium were measured at 1650 K in the concentration range 0 < xHf < 0.50 by high-temperature isoperibolic calorimetry. The experimental data obtained indicates exothermic effects upon alloy formation, which confirm a strong interaction of the components in copper ― hafnium melts.

Bonded niobium silicide and molybdenum silicide composite articles using semi-solid brazes

Abstract: An airfoil having a melting temperature of at least about 1500° C. and comprising a first piece and a second piece joined by a braze to the first piece. The first piece comprises one of a first niobium-based refractory metal intermetallic composite and a first-based refractory metal intermetallic composite, and the second piece comprises one of a second niobium-based refractory metal intermetallic composite and a second molybdenum-based refractory metal intermetallic composite. The braze joining the first piece to the second piece is a semi-solid braze that comprises a first component and a second component. The first component of the semi-solid braze comprises a first element and a second metallic element, wherein the first element is one of titanium, palladium, zirconium, niobium, germanium, silicon, and hafnium, and the second metallic element is a metal selected from the group consisting of titanium, palladium, zirconium, niobium, hafnium, aluminum, chromium, vanadium, platinum, gold, iron, nickel, and cobalt, the second metallic element being different from the first element. The second component has a melting temperature of at least about 1450° C. and comprises one of niobium, molybdenum, titanium, hafnium, silicon, boron, aluminum, tantalum, germanium, vanadium, tungsten, zirconium, and chromium. This abstract is submitted in compliance with 37 C.F.R. 1.72(b) with the understanding that it will not be used to interpret or limit the scope of or meaning of the claims.

Anodization of hafnium in phosphate baths: Radio tracer studies

Abstract: The kinetics of anodic oxidation of hafnium in different phosphate baths: Phosphoric acid and its three sodium salts of 0.1 M concentration have been carried out using galvanostatic technique at 8 mA.cm - 2 current density and at room temperature (300 K). The conventional plots V-t, 1/C-t, 1/C-V are drawn. Thickness estimates are made from capacitance data. The above plots are found to be linear up to 140 ′ 20 V. The breakdown voltage remained almost same. The parameters formation rate, current efficiency and differential field are calculated and are found to be decreasing regularly with the increase in the pH of the electrolyte. In order to establish the mechanism of oxide film formation on hafnium in Na 3 PO 4 electrolyte, the uptake and distribution of phosphate ions during formation and thinning of the oxide film are studied using 3 2 PO 4 as radio tracer and a specially designed radio active cell. For thinning experiments 0.7 μ diamond paste is used. The total mechanism is found to be via vacancy diffusion plus some exchange interstitial capture. The active-inactive transformation study clearly shows the migration of phosphate ions from one layer to another. Finally the effect of temperature and current density on the amount of incorporation of ions is also studied and linear relationships are established.

Insulating film-forming method, and semiconductor device and manufacturing method thereof

Abstract: PROBLEM TO BE SOLVED: To achieve a reliable high-k film having superb insulating characteristics. SOLUTION: After a metal hafnium layer 12 is formed on a silicon substrate 10, the surface of the silicon substrate 10 and the metal hafnium layer 12 are oxidized, thus forming a silicon oxide film 14 containing Hf set to be a high-k film on the surface of the silicon substrate 10. COPYRIGHT: (C)2003,JPO

Method of manufacturing high purity zirconium and hafnium

Abstract: The present invention relates to high-purity zirconium or hafnium with minimal impurities, particularly where the content of alkali metal elements such as Na, K; radioactive elements such as U, Th; transitional metals or heavy metals or high melting point metal elements such as Fe, Ni, Co, Cr, Cu, Mo, Ta, V; and gas components such as C, O, etc. is extremely reduced, as well as to an inexpensive manufacturing method of such high-purity zirconium or hafnium, thereby reducing the impurities hindering the guarantee of the operational performance of semiconductors. The present invention further relates to an inexpensive and safe manufacturing method of high-purity zirconium or hafnium powder from hydrogenated high-purity zirconium or hafnium powder.

Sputter target, gate insulating film and electronic component

Abstract: PROBLEM TO BE SOLVED: To provide a sputter target, by which a gate insulating film having high uniformity of a film thickness and consisting of hafnium oxide or zirconium oxide can be formed, and to provide an insulation film and an electronic component. SOLUTION: The sputter target is made of hafnium, zirconium or their alloy. The average crystal grain diameter of its surfaces to be sputtered is <=500 μm, and the variance of the average crystal grain diameter lies within 20%. The gate insulation film consists of a hafnium oxide or zirconium oxide film, formed by using the sputter target in the atmosphere of gaseous oxygen. The electronic component is provided with the gate insulating film.

Absorptance Measurements of Optical Coatings - A Round Robin

Abstract: An international round robin study was conducted on the absorption measurement of laser-quality coatings. Sets of optically coated samples were made by a reactive DC magnetron sputtering and an ion beam sputtering deposition process. The sample set included a high reflector at 514 nm and a high reflector for the near infrared (1030 to 1318 nm), single layers of silicon dioxide, tantalum pentoxide, and hafnium dioxide. For calibration purposes, a sample metalized with hafnium and an uncoated, superpolished fused silica substrate were also included. The set was sent to laboratory groups for absorptance measurement of these coatings. Whenever possible, each group was to measure a common, central area and another area specifically assigned to the respective group. Specific test protocols were also suggested in regards to the laser exposure time, power density, and surface preparation.