Physical vapor target constructions

Details Physical vapor target constructions Physical vapor target constructions

2000-10-13

2003-01-07

VerSteeg, Steven H. (Department: 1753)

Chemistry: electrical and wave energy

Apparatus

Coating, forming or etching by sputtering

C204S298130, C428S192000, C428S457000, C428S544000

Reexamination Certificate

active

06503380

ABSTRACT:

TECHNICAL FIELD
The invention pertains to physical vapor deposition target constructions and to methods of treating physical vapor deposition targets.
BACKGROUND OF THE INVENTION
Physical vapor deposition methods (which include, for example, sputtering methods) have wide application in fabrication processes when thin films are desired. For instance, sputtering processes are frequently utilized in semiconductor processing applications for forming thin films across a semiconductor substrate.
An exemplary sputtering process is described with reference to FIG.
1
. Specifically, an apparatus
10
is shown comprising a physical vapor deposition target
12
above a semiconductor substrate
14
. To aid in interpretation of the claims that follow, the terms “semiconductive substrate” and “semiconductor substrate” are defined to mean any construction comprising semiconductive material, including, but not limited to, bulk semiconductive materials such as a semiconductive wafer (either alone or in assemblies comprising other materials thereon), and semiconductive material layers (either alone or in assemblies comprising other materials). The term “substrate” refers to any supporting structure, including, but not limited to, the semiconductive substrates described above.
Target
12
has a sputtering surface
15
. In operation, ions or atoms (not shown) are impacted against a sputtering surface
15
and utilized to eject material from the sputtering surface toward substrate
14
. The ejected material is illustrated by downwardly-directed arrows. The arrows are a standard way of showing ejected material relative to a physical vapor deposition target. An alternative description of the ejected material is to show the material as a cloud
16
, since the ejected material generally has an appearance of a mist. The ejected material tends to migrate in three dimensions, rather than simply toward substrate
14
, and accordingly, some of the ejected material returns to target
12
.
The illustrated apparatus shows target
12
bonded to a backing plate
18
. Further, target
12
is shown to comprise a sidewall surface
20
which joins to a periphery of sputtering surface
15
. Also, backing plate
18
is shown to comprise a sidewall surface
22
which is coextensive with sidewall surface
20
of target
12
. Cloud
16
overlaps surfaces
20
and
22
, and accordingly some of the ejected material from sputtering surface
15
is redeposited on sidewall surfaces
20
and
22
.
The redeposited material can be problematic in semiconductor device fabrication. In an exemplary process, target
12
comprises titanium, and is sputtered in a nitrogen-containing gas to sputter-deposit a layer of titanium nitride over substrate
14
.
FIG. 2
illustrates an expanded view of substrate
14
after deposition of titanium nitride over a surface of substrate
14
. Specifically,
FIG. 2
shows that target
14
has an opening
30
extending therein, and that a deposited titanium nitride film
32
extends over substrate
14
and within opening
30
. Opening
30
can ultimately be utilized for fabrication of a semiconductor device. Opening
30
has a width, and a continuing goal of semiconductor device processing is to decrease a width of semiconductor components to enable higher densities of components to be formed over the same footprint of a semiconductor substrate. Accordingly, a continuing goal of semiconductor device fabrication is to enable uniform deposition of thin films within openings having ever-narrower widths. A problem encountered as the width of opening
30
decreases is that small particle contaminants that are non-problematic relative to large openings, become problematic relative to small openings. An exemplary contaminant is a flake
34
shown in
FIG. 2
, and shown partially occluding opening
30
. Flake
34
can be formed from material which has redeposited on sidewall surface
20
of target
12
, and subsequently fallen from target
12
onto a surface of substrate
14
. Flake
34
can render it difficult, or even impossible, to form a desired device associated with opening
30
. Accordingly, it would be desirable to alleviate or prevent flakes of redeposited material from falling from a target surface onto a semiconductor substrate during sputtering operations.
SUMMARY OF THE INVENTION
In one aspect, the invent ion encompasses a method of treating a physical vapor deposition target. The target has a sputtering surface and a sidewall edge at a periphery of the sputtering surface. The method comprises pressing a tool against the sidewall edge to form a distribution of imprints in the sidewall edge of the target. The tool is then removed from the sidewall edge, leaving the imprints extending into the sidewall edge.
In another aspect, the invention encompasses a physical vapor deposition target. The target includes a sputtering surface having an outer periphery, and a sidewall edge along the outer periphery of the sputtering surface. The sidewall edge has a repeating pattern of imprints extending therein.


REFERENCES:
patent: 3630881 (1971-12-01), Lester et al.
patent: 3985635 (1976-10-01), Adam et al.
patent: 4551216 (1985-11-01), Argyo
patent: 4855033 (1989-08-01), Hurwitt
patent: 5269894 (1993-12-01), Kerschbaumer
patent: 5282943 (1994-02-01), Lannutti et al.
patent: 5336386 (1994-08-01), Marx et al.
patent: 5538603 (1996-07-01), Guo
patent: 5589040 (1996-12-01), Nishimura
patent: 5632869 (1997-05-01), Hurwitt et al.
patent: 5658442 (1997-08-01), Van Gogh et al.
patent: 5753090 (1998-05-01), Obinata
patent: 5755887 (1998-05-01), Sano et al.
patent: 6086735 (2000-07-01), Gilman et al.
patent: 6162297 (2000-12-01), Mintz et al.
patent: 06-306597 (1994-11-01), None
patent: 2001-316798 (2001-11-01), None
patent: WO 98/31845 (1998-07-01), None
patent: 01/32018 (2001-11-01), None

Affiliated with

Also associated with

Rating

Physical vapor target constructions does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Physical vapor target constructions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Physical vapor target constructions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3003048