US3751293A - Method for reducing interdiffusion rates between thin film components - Google Patents

Method for reducing interdiffusion rates between thin film components Download PDF

Info

Publication number
US3751293A
US3751293A US00813421A US3751293DA US3751293A US 3751293 A US3751293 A US 3751293A US 00813421 A US00813421 A US 00813421A US 3751293D A US3751293D A US 3751293DA US 3751293 A US3751293 A US 3751293A
Authority
US
United States
Prior art keywords
thin film
rates
gold
metal
reducing
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00813421A
Other languages
English (en)
Inventor
H Theuerer
P Turner
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
AT&T Corp
Original Assignee
Bell Telephone Laboratories Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bell Telephone Laboratories Inc filed Critical Bell Telephone Laboratories Inc
Application granted granted Critical
Publication of US3751293A publication Critical patent/US3751293A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
    • C23C14/14—Metallic material, boron or silicon
    • C23C14/18—Metallic material, boron or silicon on other inorganic substrates
    • C—CHEMISTRY; METALLURGY
    • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
    • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
    • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
    • C23C14/22—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the process of coating
    • C23C14/24—Vacuum evaporation
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10N97/00—Electric solid-state thin-film or thick-film devices, not otherwise provided for

Definitions

  • ABSTRACT 5 I E 3 S 4 22 A method for reducing interd1ffus1on rates between [58] Fie'ld 6 217 227 1 thin film conductive components.
  • the method comprises vacuum depositing the conductive films at a par- [56] Refrences Cited tial pressure of 10-70 nicrons in the presence of an t UNITED STATES PATENTS met (e g Argon) 3,028,663 4/1962 lwersen et al l-l7/l07 5 Claims, 2 Drawing Figures PAIENIEUMIB Hm 1660 HRS H c. THEUERER MEMO P.A.
  • TURNER B A TTORNEV METHOD FOR REDUCING INTERDIFFUSION RATES BETWEEN THIN FILM COMPONENTS
  • This invention relates to a technique for reducing the interdiffusion rates of thin film components. More particularly, the present invention relates to a technique for reducing the interdiffusion rates between thin film conductive components wherein the components of interest are deposited by vacuum evaporation techniques in the presence of a non-reactive gas.
  • the prior art difficulties encountered in connection with such thin film composites have been significantly lessened by a novel technique which causes a reduction in interdiffusion rates between the components of the composite.
  • the inventive technique involves depositing thin film conducting composites by vacuum evaporation techniques in the presence of a suitable non-reactive gas. Studies have revealed that processing in the tile. scribed manner results in the reduction of the diffusivity of metals by segregating diffusion paths and impeding the movement of diffusants by incorporation of the gas of interest in grain boundaries and dislocation cores.
  • FIG. 1 is a front elevational view of an apparatus suitable for use in producing a film of metal by vacuum evaporation techniques in accordance with the present invention.
  • FIG. 2 is a graphical representation on coordinates of time in hours against reflectivity showing diffusion rates for gold-silver thin film couples prepared in accordance with the present invention.
  • FIG. 1 shows a suitable vacuum evaporation apparatus for depositing thin films in accordance with the invention.
  • a vacuum chamber 11 containing filament l2 and platform 13, which latter is employed as a positioning support for substrate 14.
  • Mask 15 is utilized as shown to restrict the deposition of the film to the desired area.
  • the ends of filament 12 are connected to electrical leads 16 to permit flow of current therethrough from a source (not shmgn).
  • the apparatus also includes an inlet 17 for the introduction of gas during the processing and an outlet 18 for removal of gas, outlet 18 being connected to a suitable pump (not shown).
  • the present invention has been described largely in terms of the deposition of gold-silver composites. However, it will be appreciated that such description is solely for purposes of exposition and that any metal capable of being deposited'in thin film form by vacuum evaporation techniques may be obtained in the described manner. Metals found to be particularly useful for thin film applications and amenable to such processing include aluminum, copper, nickel, iron, Pennalloy, etc.
  • the invention may conveniently be described by reference to an illustrative embodiment wherein silver and gold are employed as the thin film couple.
  • An apparatus similar to that shown in FIG. 1 may conveniently be employed for the purpose of effecting deposition of the films;
  • the conditions employed in the vacuum evaporation process are well known .(see Vacuum Deposition of I Thin Films, L. Holland, John Wiley & Sons, Inc., New York, I956).
  • the extent of the vacuum is dictatedby consideration of the vapor pressurev of the metal to be evaporated.
  • the vapor pressure of the metal to be evaporated should beat least ten times greater than the pressure to which the system is evacuated. In general, better quality films are-obtained at a'higher vacuum.
  • themaximum pressure which can be tolerated is that above which the oxygen present inte'rferes-with the deposition of a pure metallic film.
  • the usual method of heating the metal to be evaporated is to position it in proximity to a filament which may be heated electrically. This end is conveniently accomplished by using a tungsten filament in the shape of a coil, as shown in FIG. 1, and placing the metal to be evaporated within the coil. The required temperature is obtained by controlling the magnitude of the current flowing through the filament. Alternatively, a filament of the metal to be evaporated may be used in those instances where the metal has a sufficiently high vapor pressure at temperatures below its melting point.
  • the substrate member upon which deposition is to be effected may be selected from among glasses, glazed ceramics, high melting metals and any thin film circuitry requiring the deposition of a metal composite thereon.
  • the substrate member is first cleaned for the purpose of removing contaminants therefrom, any well-known cleansing technique being suitable for this purpose.
  • Substrate 14 is then placed upon platform 13 and mask 15 suitably positioned.
  • vacuum chamber 11 is evacuated to a pressure of the order of 10"torr. .and a non-reactive gas admitted thereto.
  • non-reactive applies to gases which do not normally enter into chemical reaction with metals. It has been found that argon, helium,
  • tungsten filament 12 After the requisite pressure is obtained, a current is passed through tungsten filament 12, thereby heating the filament and causing the metal of interest to evaporate. Evaporation is continued for a time period sufficient to produce a thin film of the desired thickness. Thereafter, at least one additional metal is deposited in the foregoing manner upon the film so produced.
  • the thickness of the deposited layers is of no criticality and it is solely dependent upon the specific role that the metal composite is to play in the resultant circuitry.
  • This example describes the production of a thin film couple in accordance with the invention wherein gold and silver are successively evaporated upon a substrate.
  • the filament being composed of a 5 turn tungsten coil.
  • the substrate selected was a glass microscope slide which was cleaned by ultrasonic cleansing in AL- CONOX, and successively boiling in a three part hydrocloric acid-one part SUPEROXOL solution, rinsing in deionized water, vapor drying with isopropyl alcohol and baking at 560 C. for l5 minutes in air to remove residual carbonations material.
  • the slide was placed approximately 3% inches from the tungsten filament and a mask placed on the slide.
  • a 1 inch piece of gold, 25 mils in diameter was placed within the tungsten filament.
  • the vacuum chamber was evaporated to a pressure of approximately 1 X10 torr. and 35 microns of Hg of argon admitted to the chamber. Current was caused to flow through the tungsten filament, heating it to incandescence and causing the evaporation of the gold wire.
  • the 1 inch piece of gold wire was completely evaporated within five minutes and a layer of gold 1500 angstroms thick was produced on the exposed portions of the slide. Then, a new tungsten coil was inserted in the apparatus and a silver wire 1 inch in length was inserted in the coil. The evaporation procedure was repeated, so resulting in the evaporation of a layer of silver 5,000
  • Optical reflectivity (which is directly related to composition) as a function of time was then measured at the gold-glass interface by conventional techniques. After 49 hours, the reflectivity was found to drop approximately 7 percent, so indicating that a small amount of silver had migrated into the gold film. Thereafter it was found that optical reflectivity remained constant for greater than 5625 hours. 7
  • Optical re flectivity was found to decrease approximately 15 percent after 25 hours, 35% after 100 hours and about 45% after 400 hours. Thereafter the optical reflectivity was found to remain constant at that level for greater than 4900 hours.
  • Example 1 The procedure of Example 1 was repeated with the exception that helium was employed as the nonreactive gas. Optical reflectivity was found to drop approximately 7 percent after 49 hours and remained constant thereafter for more than 5625 hours.
  • FIG. 2 there is shown a graphical representation on coordinates of time in hours against reflectivity in per cent showing variations in optical reflectivity as a function of time (or diffusion rates) for thin film gold-silver couples. It is noted that utilizing 35 and microns of Hg of argon or helium, respectively, as the non-reactive gas in the practice of the present invention results in only a slight decrease in reflectivity as compared with optical reflectivity changes manifested by gold-silver couples evaporated in the absence of such gases.
  • a method for reducing interdiffusion rates between thin film conductive components which com-. prises the steps of successively depositing at least two metals capable of being deposited in thin film form by vacuum evaporation upon a suitable substrate by vacuum evaporation techniques in the presence of a nonreactive gas, selected from the group consisting of argon, helium, neon, xenon, krypton, radon and hydrogen, the partial pressure of said gas ranging from 10 to 70 microns.
  • a nonreactive gas selected from the group consisting of argon, helium, neon, xenon, krypton, radon and hydrogen, the partial pressure of said gas ranging from 10 to 70 microns.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Inorganic Chemistry (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physical Vapour Deposition (AREA)
  • Internal Circuitry In Semiconductor Integrated Circuit Devices (AREA)
US00813421A 1969-04-04 1969-04-04 Method for reducing interdiffusion rates between thin film components Expired - Lifetime US3751293A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US81342169A 1969-04-04 1969-04-04

Publications (1)

Publication Number Publication Date
US3751293A true US3751293A (en) 1973-08-07

Family

ID=25212323

Family Applications (1)

Application Number Title Priority Date Filing Date
US00813421A Expired - Lifetime US3751293A (en) 1969-04-04 1969-04-04 Method for reducing interdiffusion rates between thin film components

Country Status (7)

Country Link
US (1) US3751293A (enrdf_load_stackoverflow)
BE (1) BE748215A (enrdf_load_stackoverflow)
DE (1) DE2015457B2 (enrdf_load_stackoverflow)
FR (1) FR2042936A5 (enrdf_load_stackoverflow)
GB (1) GB1306113A (enrdf_load_stackoverflow)
NL (1) NL145285B (enrdf_load_stackoverflow)
SE (1) SE364317B (enrdf_load_stackoverflow)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4407871A (en) * 1980-03-25 1983-10-04 Ex-Cell-O Corporation Vacuum metallized dielectric substrates and method of making same
US4431711A (en) * 1980-03-25 1984-02-14 Ex-Cell-O Corporation Vacuum metallizing a dielectric substrate with indium and products thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3028663A (en) * 1958-02-03 1962-04-10 Bell Telephone Labor Inc Method for applying a gold-silver contact onto silicon and germanium semiconductors and article
US3063858A (en) * 1959-07-22 1962-11-13 Nat Res Corp Vapor source and processes for vaporizing iron, nickel and copper
US3402073A (en) * 1964-08-04 1968-09-17 Texas Instruments Inc Process for making thin film circuit devices

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3028663A (en) * 1958-02-03 1962-04-10 Bell Telephone Labor Inc Method for applying a gold-silver contact onto silicon and germanium semiconductors and article
US3063858A (en) * 1959-07-22 1962-11-13 Nat Res Corp Vapor source and processes for vaporizing iron, nickel and copper
US3402073A (en) * 1964-08-04 1968-09-17 Texas Instruments Inc Process for making thin film circuit devices

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Holland; L., Vacuum Deposition of Thin Films, N.Y., John Wiley & Sons Inc., 1956, pg. 4. *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4407871A (en) * 1980-03-25 1983-10-04 Ex-Cell-O Corporation Vacuum metallized dielectric substrates and method of making same
US4431711A (en) * 1980-03-25 1984-02-14 Ex-Cell-O Corporation Vacuum metallizing a dielectric substrate with indium and products thereof

Also Published As

Publication number Publication date
GB1306113A (enrdf_load_stackoverflow) 1973-02-07
DE2015457A1 (de) 1970-10-08
NL145285B (nl) 1975-03-17
BE748215A (fr) 1970-08-31
NL7004622A (enrdf_load_stackoverflow) 1970-10-06
FR2042936A5 (enrdf_load_stackoverflow) 1971-02-12
SE364317B (enrdf_load_stackoverflow) 1974-02-18
DE2015457B2 (de) 1972-02-10

Similar Documents

Publication Publication Date Title
US3106489A (en) Semiconductor device fabrication
US3844924A (en) Sputtering apparatus for forming ohmic contacts for semiconductor devices
US3042550A (en) Solid delay line improvements
US3241931A (en) Semiconductor devices
US3480412A (en) Method of fabrication of solder reflow interconnections for face down bonding of semiconductor devices
US3339267A (en) Metallizing non-metals
US3701931A (en) Gold tantalum-nitrogen high conductivity metallurgy
US2539149A (en) Vapor coating process
US3258413A (en) Method for the fabrication of tantalum film resistors
US4025404A (en) Ohmic contacts to thin film circuits
US4035526A (en) Evaporated solderable multilayer contact for silicon semiconductor
US3616406A (en) Preparation of glue layer for bonding gold to a substrate
US3922385A (en) Solderable multilayer contact for silicon semiconductor
US3377697A (en) Method of terminating thin film components
US3751293A (en) Method for reducing interdiffusion rates between thin film components
US3518066A (en) Metallizing non-metals
US2831784A (en) Gastinger
US3655544A (en) Refractory metal/refractory metal nitride resistor films
US3125654A (en) Electrical contacting surfaces
US4309460A (en) Process for producing gold films
US3886585A (en) Solderable multilayer contact for silicon semiconductor
US3723178A (en) Process for producing contact metal layers consisting of chromium or molybdenum on semiconductor components
US4559278A (en) Electrolytically rhenium coated molybdenum current inlet conductor assembly for vacuum lamps
US3990094A (en) Evaporated solderable multilayer contact for silicon semiconductor
EP0033358B1 (en) Process for fabricating thin metal superconducting films of improved thermal cyclability and device