U.S. patent application number 09/386789 was filed with the patent office on 2002-01-03 for self-repairing interconnections for electrical circuits.
Invention is credited to KOZICKI, MICHAEL N..
Application Number | 20020000666 09/386789 |
Document ID | / |
Family ID | 26794922 |
Filed Date | 2002-01-03 |
United States Patent
Application |
20020000666 |
Kind Code |
A1 |
KOZICKI, MICHAEL N. |
January 3, 2002 |
SELF-REPAIRING INTERCONNECTIONS FOR ELECTRICAL CIRCUITS
Abstract
A self-repairing interconnection system and methods for forming
the system are disclosed. The system includes a metal pathway
adjacent a metal-doped chalcogenide material. The system is
configured to repair defects in the metal pathway by donating
metallic ions from the metal-doped chalcogenide material to the
metal pathway.
Inventors: |
KOZICKI, MICHAEL N.;
(PHOENIX, AZ) |
Correspondence
Address: |
SNELL & WILMER LLP
ONE ARIZONA CENTER
PHOENIX
AZ
850040001
|
Family ID: |
26794922 |
Appl. No.: |
09/386789 |
Filed: |
August 31, 1999 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60098609 |
Aug 31, 1998 |
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Current U.S.
Class: |
257/758 ;
257/E23.146; 257/E23.154 |
Current CPC
Class: |
H01L 2924/0002 20130101;
H01L 2924/0002 20130101; H01L 23/525 20130101; H01L 2924/00
20130101; H01L 23/532 20130101 |
Class at
Publication: |
257/758 |
International
Class: |
H01L 023/48; H01L
023/52; H01L 029/40 |
Claims
I claim:
1. A self-healing interconnect system comprising: a metal
interconnection pathway; and a metal-doped chalcogenide material
adjacent said metal interconnection pathway.
2. A method of forming a self-healing interconnect system, said
method comprising of steps of: forming a metal-doped chalcogenide
material; and forming metal pathways adjacent said metal doped
chalcogenide material.
Description
RELATED APPLICATIONS
[0001] This application claims the benefit of pending Provisional
Application Ser. No. 60/098,609, filed Aug. 31, 1998.
TECHNICAL FIELD
[0002] The present invention generally relates to methods and
apparatus for forming self-repairing interconnections for
electrical circuits. More particularly, the present invention
relates to an interconnection system using metal-doped chalcogenide
material in contact with metal interconnections which heal defects
in the metal interconnections.
BACKGROUND
[0003] The performance and cost of electronic systems have improved
continuously due in part to advances in manufacturing progressively
smaller electronic devices. Advances in semiconductor technology
have resulted in a tremendous reduction in the feature sizes of
electronic devices, thereby increasing the density of electrical
circuits. In fact, over the past two decades, the density of
components which can be located on a single microchip has increased
by a factor of 100 per decade.
[0004] As the density of components has increased, so has the
requirement for the density of interconnection pathways formed
between these components. In order to increase the density of
interconnection pathways, the size of interconnections must be
reduced. Small geometry interconnections, however, are highly prone
to failure by electromigration at points where the lines have a
reduced cross-section due to thinning at topographical features
(e.g., an underlying step), line narrowing by reflective notching
during a photolithography step, and morphological effects such as
width variations at grain boundaries after etching. The ultimate
quality and reliability of many electronic systems are determined
largely by the reliability of the interconnection system.
[0005] To mitigate problems associated with high density devices
and increase device reliability, metal lines are desirably designed
or made wider than the minimum lithographical line width,
preferably by a factor of two or more, to reduce current density at
the thin regions of the lines and thereby reduce electromigration.
Manufacturing devices with wider lines, however, reduces the
overall interconnection density for the devices.
[0006] Therefore, interconnections capable of healing defects
and/or breaks in interconnection pathways are highly desirable to
thereby increase overall system reliability.
SUMMARY OF THE INVENTION
[0007] The present invention relates to methods and apparatus for
forming self-healing interconnections for electrical circuits. In
accordance with an exemplary embodiment of the present invention,
an interconnection metal (e.g., copper, silver, and the like) is
deposited on a layer of metal-doped chalcogenide material. When
breaks occur in the interconnection metal, the break is healed
(i.e., filled in) by the formation of a metal element formed by
metal precipitation at the break.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
[0008] The present invention will hereinafter be described in
conjunction with the appended drawing figures, wherein like
numerals denote like elements, and:
[0009] FIG. 1 is a sectional schematic illustration of a
multi-level interconnection system in accordance with one aspect of
the present invention; and
[0010] FIGS. 2A-2C are schematic depictions of a break and healing
process in an interconnection pathway in accordance with the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] In order to provide a more thorough understanding of the
present invention, the following description sets forth numerous
specific details, such as specific material, parameters, etc.
However, these specific details need not be employed to practice
the present invention.
[0012] With reference to FIG. 1, a multi-level self-healing
interconnect system 10 in accordance with a preferred embodiment of
the present invention is shown. In accordance with one aspect of
the present invention, interconnection system 10 includes a
plurality of metal interconnection pathways 18 in contact with a
metal-doped chalcogenide material 12, dielectric separation layers
14, and vias 16.
[0013] In accordance with one aspect of the present invention, a
suitable metal-doped chalcogenide material includes any compound
containing sulfur, selenium and/or tellurium, whether ternary,
quaternary or higher compounds. In a preferred embodiment of the
present invention, the chalcogenide material is selected from the
group consisting of arsenic, germanium, selenium, tellurium,
bismuth, nickel, sulfur, polonium and zinc (preferably, arsenic
sulphide, germanium sulfide, or germanium selenide) and the metal
comprises various Group I or Group II metals (preferably, silver,
copper, zinc or a combination thereof). The metal-doped
chalcogenide material may be obtained by photo dissolution, by
depositing from a source comprising the metal and chalcogenide
material, or by other means known in the art. For a more detailed
discussion of metal-doped chalcogenide material, see U.S. Pat. No.
5,761,115, issued on Jun. 2, 1998 to Kozicki et al, the entire
disclosure of which is incorporated herein by reference.
[0014] In an exemplary embodiment, chalcogenide material 12 is
doped with silver or copper. In accordance with this embodiment,
metal pathways 18 are also formed from silver or copper. However,
any conductive material may be used as long as there are no adverse
reaction between the conductor and the chalcogenide material.
[0015] In accordance with one aspect of the present invention,
metal pathways 18 are deposited on and in contact with chalcogenide
material 12 using any convenient deposition method. Although in
FIG. 1 metal pathways 18 are depicted above chalcogenide material
12, metal pathways 18 can be deposited beneath or completely within
chalcogenide material 12. Additionally, vias 14 are preferably kept
free of the metal-doped chalcogenide material to minimize the
resistance of the connection between interconnect layers.
[0016] With reference to FIG. 2A, a defect in a conductor pathway
22 can result from thinning at topographical features (e.g., an
underlying step), line narrowing by reflective notching during a
photolithography step, morphological effects such as width
variations at grain boundaries after etch, and the like. With
additional reference to FIG. 2B, as a weak region 23 in conductor
pathway 22 becomes thinner (e.g., by electromigration), pathway 22
resistance increases, thereby also increasing the voltage drop
across pathway 22. With additional reference to FIG. 2C, this
potential difference creates an electric field which moves
dissolved metal ions from metal-doped chalcogenide material 24 to
the most electrically negative part of the defect, whereupon the
metal ions will come out of solution and form a solid metal element
26 (e.g., a dendrite) at the surface of chalcogenide material 24.
Metal element 26 will grow until the defect is bridged (i.e.,
returned to a low resistance state). Although metal element 26 is
depicted in FIG. 2C as substantially oval, metal element 26 may
assume any suitable shape.
[0017] In this manner, defects and breaks in interconnection
pathways can be repaired in-situ. Additionally, as described above,
this repair mechanism is self-regulating as it will only operate
when the defect resistance becomes high and will turn-off when the
repair is complete. Accordingly, the present self-healing
interconnection system provides for increased system
reliability.
[0018] While preferred embodiments of the present invention have
been shown in the drawings and described above, it will be apparent
to one skilled in the art that various embodiments of the present
invention are possible. For example, the present invention may be
used to cure interconnection pathways in 3-dimensional circuits or
any semiconductor or integrated circuit application. Therefore, the
present invention should not be construed as limited to the
specific form shown and described above.
* * * * *