JPS61110461A - Conductive film strip - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the cutting out of thin film conductors, particularly thin film strips with high electrophoretic resistance.

BACKGROUND OF THE INVENTION Thin, narrow strips made of conductive metals, such as aluminum, have been used in solid state devices for some time to interconnect various types of device components. Similar conductor strips are also currently used in magnetic bubble memories. At the current state of technology, the application of these integrated circuits is unprecedented! a wipe(voryLarge 5cale Int
(VLSI), the physical dimensions of the interconnects become correspondingly smaller, and electrophoretic disruption (VLSI) approaches.
The ability of interconnects to resist FMD (mags) (FMD) is of increasing importance. When the dimensions of mutual coalescence approach micron or submicron dimensions, the current density carried by the band becomes sparse within one area of the band due to mass transport of atoms, and the direction of the current changes. The conductor increases from the first @ moth to the m change where density occurs in the conductor around the second head on the downstream side. At current densities below 10' amp/ryt, electrophoresis has little effect on the life of thin film conductors. However, at current densities of about 10' amp/ryt and above, electrophoretic damage occurs. Reduces the lifetime of the circuit. Failure can occur due to open circuits that occur in sparse areas or, in dense areas, due to short circuits that occur when expanded material comes into contact with other conductors. Many of this type It should be noted that the thin film conductor of is provided with an inert layer, such as glass, and that this layer is damaged by the material buildup K. Breakage exposes the electronic components to a harmful atmosphere and further : Causes premature failure of the equipment carrying Itl.

It has been noticed by many researchers that hydrogen-containing air can mutually improve the electromobility behavior of thin film conductors. Evidence has been developed that the interaction of active gases such as hydrogen with thin film conductors or bimetallic diffusion couples results in a reduction in fragility within solid state transport. The intermetallic compound formation rate is
In a diffusion coupled device, it is dramatically reduced when the device is placed in an atmosphere of hydrogen rather than air. International Reliability Physical Symposium 8
7-90 Sada (1979) Nori, YShih and P.
T.

See Ficalova's method. It is also noted that the mean time to failure (MTF) of thin film conductors increases considerably when the aluminum strip is vacuum deposited in a hydrogen-containing atmosphere. For example, Journal Oppacium Science Technology, Volume 17, pp. 322-326 (
(1980) Reference Nori, F., Mayer.

(The bright spot while the invention is trying to solve) The technological importance of hydrogen atmospheres is now clear.

It can also be shown that by using this technique, significant improvements in electrical line performance can be achieved compared to the results obtained by changing the composition of the conductor.

U.S. Patent Nos. 4,352,239, 4,017,890, 4,166,279, 4,268,584, 37,253
No. 09 all show various component arrangements used for the purpose of suppressing electrophoresis in conductor strips. death,
However, to date, little is known about devices in which compositional or atmospheric changes actually occur during the electrophoresis of micron or submicron conductors.

It is therefore an object of the present invention to improve thin film interconnects.

A second object of the invention is to extend the service life of thin film conductors used in high current density applications.

A second object of the invention is to suppress electrophoresis in micron and submicron conductors.

A further object of the invention is to obtain a highly reliable microelectronic circuit.

SUMMARY OF THE INVENTION These and other objects of the invention are obtained by a thin film conductor having a high resistance to electrophoresis, the film conductor being capable of storing conductive metal elements and hydrogen. It is formed of an alloy with at least one other element. The alloy is first purified in a hydrogen atmosphere before or during the application of the current, combining the hydrogen with the storage element and thereby pre-filling the conductor with hydrogen.

BRIEF DESCRIPTION OF THE DRAWINGS For a better understanding of these and other objects of the invention, examples of the invention will now be described in detail with reference to the accompanying drawings.

Referring to FIG. 1, there is shown at K a hermetically sealed package 10 containing an integrated circuit 11 for use in a microelectronic device. The package has a flat packaging shape,
Exaggerated dimensions are shown for clarity purposes. The package has a housing 12 with horizontal conductors 13-13 running through opposite side walls to which the integrated circuit 11 stored therein is electrically coupled to VC#II. The upper part of the housing is made of gold-tin solder and is provided with a hammer seal 16, to which a Kovar 417 is attached. When placed in place, the assembly is heated to a temperature high enough to allow the wax to flow over the rose and the housing thereby forms a hermetic seal. A hydrogen-containing atmosphere 19 is introduced into the housing, which completely surrounds the microelectronic circuit.

As technically representative,! The product circuit has a substrate on which one or more electrical components, such as component 21, are placed. Thin film interconnects, or bands, join the components within the assembly.

The strip can be deposited onto the substrate by any of a number of known techniques, including vacuum deposition or bombardment. In this particular embodiment, the thin film conductor is arranged to pass current densities in excess of 10' ampA2, and therefore, if unsuppressed, electrophoretic and electrophoretic damage would result in electrical damage to the device. It is easy to receive.

The thin film strip is formed of a current transporting element alloyed with a second element capable of accepting and storing hydrogen therein. The current transport or conductive element is preferably aluminum and the hydrogen storage element is titanium alloyed with aluminum in an amount between 0.01% and 0.251% by weight. Alloying is carried out in any suitable equipment known and used in the art. After being deposited on the substrate, the thin film was heated at 400°C - 50' while it was placed in a hydrogen atmosphere.
It is annealed at a temperature of c. The solubility of titanium in aluminum is approximately 0.07-0.0.0% by weight at these annealing temperatures.
It is 08-. Any undissolved titanium is TiA.
73 is a type of intermetallic compound. See Haasen's Structure of Binary Alloys, McGraw-Hill, 1958, 2nd edition.

The solubility of hydrogen in titanium is significant.

Hydrogen forms solid solutions with titanium with relatively strong chemical bonds and hydride type compounds such as TiHa.

At an annealing temperature of 400°C, about 304% of the titanium is in solid solution within the aluminum, and about 70% of the titanium is in TiAj,
It is of the type. The interaction between titanium and hydrogen differs depending on whether the titanium is in solid solution or in the form of a two-phase TiA precipitate. Because the hydrogen is in solid solution within the alloy structure, its motion in conjunction with the titanium by the solid state transport device is relatively fast. Conversely,
The titanium is also in solid solution within the thin film substituent, and intermetallic compound formation proceeds at a slower rate.

Enhancement of the inertia of thin film conductors can be achieved by various combinations of aluminum alloy strips and by treating these components in a hydrogen atmosphere before applying electrical current to the strips. Aluminum alloys with small metal components that form stable regular composition or stable non-standard composition compounds with hydrogen or exhibit high heat of solution with hydrogen are shown in the following table.

Group III-B Scandium (Sc)
1MC Yztrium (Y) X
888 IMC Rare Earth Lantern (La)
SSS IMC Cell (Ce
) X 888 1MC praseolim (Pr) DY) X 888 IMC Holmium (HO) X IMC Erbium (1
1! ! r) X 888 IMC
Umu (Tm) X
IMC Yterbium (Yb) X
IMC Lutetium (Lu)
IMC hydrogenation er” AL soluble C1 actinated series) IJ '7 A(Th) X
888 IMC Proactinium (Pa) X --Neptunium (N
p) X IMC plutonium (P
u) X sss lMC9■-Bf)
Zirconium (Ti) X IMC Zirconium (Zr) X 888 IMCM
C hafnium f)
MC Niobium (Nb) X 8
8S IMC tantalum (Ta)
X 888 IMC Group VI-B
R ROM (CR) x
888 1MC Molybdenum (MO)
X IMC details■ Palladium (Pd)
X 8B8 1MCX = hydride type or H
Highly soluble SSS = low solid solution IMC = intermetallic compound Therefore, the use of these components alone or in different combinations achieves hydrogen storage by chemically annealing the conductor in hydrogen, as described above. I can do it. Hydrogen trapped within the alloy can be a hydride or a solid solution (or a combination thereof)
is stored in the mold and therefore remains in the strip for extremely long periods of time, even when the strip is exposed to relatively high temperatures and/or pressures that would quickly destroy conventional unalloyed strip! be done.

Operation Referring to FIG. 2, at K there is shown a mounting embodying the present invention in which a thin film conductor employing the present invention is annealed in a hydrogen atmosphere. The apparatus includes an electric furnace, indicated generally at 10, the temperature of which is precisely controlled. The furnace has an enclosing housing 31 with an interior chamber 32. The housing is surrounded by a heating jacket containing a heating coil and a thick layer of insulation to prevent heat loss. The heating coil is operatively coupled to a suitable temperature control device 36 and the room temperature is controlled by a thermocuzzle 37 which serves to maintain the temperature at the desired height.
will be monitored.

The integrated circuit 11 containing the aluminum alloy strip n is mounted inside the howling chamber of the furnace on a suitable support, which support may in fact be a flat-wrapped housing 12 as shown in FIG. . A flanged and barbed fitting 39 is attached to the top wall of the furnace housing through which the chamber communicates with the gas source string and the power source 41. Overall code 45
The flow control device shown by is connected inside the P chamber through the bottom of the P chamber. The body tube has a control valve 47 and a relief push force.

Initially K, the atmospheric air in the room is replaced by a hydrogen-containing atmosphere obtained by supply @42. The temperature of the furnace with the thin film in the hydrogen atmosphere is the desired sintering temperature of 11!
will be raised to. The furnace is maintained at the annealing temperature for a sufficient period of time to sufficiently fill the alloyed zone with hydrogen. The annealing range and raq will vary depending on the type of alloy used and the amount of hydrogen storage material added to the conductor material. After annealing,
The strip is cooled to room temperature and a fully filled device is obtained. The strip can be cooled in a hydrogen atmosphere. when cooled.

The device is removed from the furnace and the package is sealed with the hydrogen atmosphere contained therein using well known techniques. Therefore, the thin film conductor contained within the package not only stores hydrogen internally, but is also adapted to operate in a hydrogen atmosphere, thus shortening the life of the device. An atmosphere containing sufficient hydrogen is preferred for packaging purposes.

(Effects of the Invention) As shown in Figure 2, storing hydrogen in the band allows VC! Hydrogen molecules turn into water in an atmosphere! ! It can be made stronger by separating it into atoms. For this purpose, a thin filament ω is mounted in the chamber directly above the processed J[circuit. The filament is pneumatically coupled to the external power supply fi411c'fIL through a flanged joint. The temperature of the filament is increased during the phosphorous dulling stage to a height such that hydrogen molecules in or near the band decompose into hydrogen atoms. For the same reason, metal band elements can be further alloyed with group II metals such as platinum and nickel, which have the ability to dissociate hydrogen on the surface of the band, thereby converting it into film atoms and/or storage elements. Provides a highly active form of hydrogen for chemical bonding.

[Brief explanation of drawings]

FIG. 1 is an enlarged cross-sectional view of a microelectronic package employing the subject matter of the present invention, and FIG. 2 is a schematic diagram of the apparatus used to carry out the invention. DESCRIPTION OF SYMBOLS 10... Packaging body, 11... 4-product circuit, 12... Housing, 13... Conductor, 16... Seal, 17...
... Lid, 19... Atmosphere, Addition... Substrate, 21, n.
...electrical component, η...band, I...electric furnace, 31...
・Housing, 32...inner chamber, ah...coil, ah...
... Insulator, A... Temperature control device, 37... Thermocouple, 39... Joint, 40... Upper wall, 41...
・Power supply source, 42...Gas supply source, 45...Flow control! @Device, 47... Control valve, Release valve, ω.
··filament. Patent Applicant: Syracuse, Uniper City ~ Deaf-3: Voluntary Proceeding Amendment December 10, 1980 1, Case Indication 1981 Patent Application No. 233007 2) Name of Invention Film Conductor Band 4, Agent

Claims (12)

[Claims] (1) A thin film conductor strip exhibiting high resistance to electrophoresis, said strip comprising a conductive metal alloyed with at least one other element capable of accepting hydrogen and chemically bonding with hydrogen. and the hydrogen is chemically bonded to the other element. (2) The film conductor band according to claim 1, wherein the conductive metal is alloyed with a plurality of elements, and each of the elements can chemically bond with hydrogen. (3) In the film conductor strip according to claim 2, each of the elements forms chemical bonds with the hydrogen with different bond strengths, so that the conductor strip can withstand a wide range of temperatures and pressures. A film conductor strip that holds chemically bonded hydrogen across it. (4) The film conductor strip according to claim 1, wherein the at least one element is a transition metal. (5) The film conductor strip according to claim 1, wherein the at least one element is a rare earth oxide metal. (6) In the film conductor band according to claim 1, the conductive metal is aluminum, and the element alloyed with the conductive metal is 0.01% to 0.025% by weight.
The film conductor strip is of added titanium in an amount between. (7) The film conductor strip according to claim 1, further comprising a hermetically sealed package for accommodating the conductor strip. (8) A thin film conductor strip with high resistance to electrophoresis, said film conductor strip comprising aluminum alloyed with at least one other element that forms chemical bonds with both aluminum and hydrogen; A film conductor band having hydrogen chemically combined with the other element. (9) In the film conductor band according to claim 8, the at least one other element is in Group-III-B, Group-IV-B, Group-VI-B, Group-VI
A film conductor band selected from the group consisting of II components. (10) The film conductor strip according to claim 8, wherein the at least one other element is a transition metal. (11) The film conductor strip according to claim 8, wherein the at least one other element is a rare earth oxide metal. (12) The film conductor strip according to claim 8, further comprising a hermetically sealed package for accommodating the conductor strip.