Patent EP0880168A2 successfully refreshed from Google Patents.
EP0880168A2
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EP
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System and method of selectively cleaning copper substrate surfaces, in-situ, to remove copper oxides
Assignee: Sharp Corp
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Filing: 1998-05-20
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Granted: —
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Expires: 2018-05-20
Abstract
Abstract A system and method are provided for selectively etching metal, preferably copper surfaces free of oxides in preparation for the deposition of an interconnecting metallic material. Metal oxides are removed with β-diketones, preferably Hhfac. The Hhfac is delivered into the system in vapor form, and reacts almost exclusively with copper oxides. The by-products are also volatile for removal from the system under reduced pressure. The procedure is easily adaptable to most IC process systems, it can be conducted in an oxygen-free environment, without the removal of the IC from the process chamber. The in situ cleaning permits a minimum amount of copper oxide to reform before the deposition of the overlying metal, permitting formation of a highly conductive electrical interconnection.
Inventors
- 👤 Tue Nguyen
- 👤 Lawrence J. Charneski
- 👤 David R. Evans
- 👤 Teng Hsu Sheng
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 06:32
CPC Classifications
C; C23; C23G; C23G5/00; H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H10P50/286; H10P50/287; H10P50/60; H10P50/66; H10P50/663; H10P50/667; H10P70/00; H10P70/20; H10P70/23; H10P70/234; H10W; H10W20/00; H10W20/01; H10W20/031; H10P70/27
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
136 words
A method for in situ cleaning a metal oxide from the surface of
the first of a plurality of metal levels, in an integrated circuit (IC) having a
dielectric interlevel with a dielectric surface and the plurality of metal levels
underlying the dielectric interlevel, the surface of the first metal level being
accessed through a via from the dielectric surface, the method comprising the
steps of: (a) surrounding the integrated circuit with a gaseous atmosphere; (b) controlling the atmosphere to be substantially free of oxygen,
whereby the formation of metal oxides on the first metal level surface is
minimized; (c) introducing a β-diketone vapor into the atmosphere; and (d) volatilizing the metal oxide from the first metal level surface using
the β-diketone vapor introduced in step (c), whereby the first metal level
surface is selectively cleaned.
Claim 2
Dependent Claim
16 words
A method according to claim 1, wherein the first metal is selected
from copper and silver.
Claim 3
Dependent Claim
51 words
A method according to claim 1 or claim 2, wherein the β-diketone
has the structural formula in which each of R and R 1 is selected from C 1 to C 6 alkyls, perfluoroalkyls,
and other substitutions, and X is selected from H, F, Cl, Br, I, alkyls,
perfluoroalkyls and substitutions.
Claim 4
Dependent Claim
12 words
A method according to claim 3, wherein the β-diketone is
hexafluoroacetylacetonate (Hhfac).
Claim 5
Dependent Claim
25 words
A method according to claim 4, wherein Hhfac is introduced in
step (c) at a pressure below 11.5 kPa and a temperature of approximately
20°C.
Claim 6
Independent Claim
33 words
A method according to any one of claims 1 to 5, including
following step (d) the further step of (e) reducing the pressure thereby to remove the metal oxides
volatilized in step (d).
Claim 7
Independent Claim
31 words
A method according to any one of claims 1 to 6, including before
step (c) the further step of (f) controlling the temperature of the IC to between 100 and 450°C.
Claim 8
Independent Claim
39 words
A method according to any one of claims 1 to 7, including
following step (d) the further step of (g) depositing a second metal level over the first metal level surface
to electrically interface to the first metal level.
Claim 9
Dependent Claim
40 words
A method according to claim 8, wherein the second metal level is
selected from TiN, TiSi x N y , TaSi x N y , TaN, WN, WSi x N y , Ti, Ta, W, Cu, Al,
Ag and Au.
Claim 10
Independent Claim
82 words
A system for use in carrying out the method of any one of claims
1 to 9, comprising a chamber (40) adapted for the control of the atmosphere therein to be
substantially free of oxygen; a bubbler (42) operatively connected to the chamber to introduce β-diketone
vapor into the chamber; and a wafer chuck (44) located within the chamber and upon which the IC
may be mounted, and means associated with the wafer chuck for maintaining
the chuck at a predetermined temperature.
Claim 11
Dependent Claim
23 words
A system according to claim 10, wherein the means is adapted to
maintain the wafer chuck at a temperature between 100 and 500°C.
Claim 12
Dependent Claim
27 words
A system according to claim 10 or claim 11, further comprising a
pump (54) operatively connected to the chamber to remove volatilized metal
oxide from the chamber.
Claim 13
Independent Claim
27 words
A system according to any one of claims 10 to 12, further
comprising a liquid injection (52) to introduce liquid precursor compounds
including metal into the chamber.
Claim 14
Independent Claim
28 words
A system according to any one of claims 10 to 12, further
comprising a vapor delivery system (52) to introduce vapor precursor
compounds including metal into the chamber.
References Cited (Backward Citations)
No citation records indexed.
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