Note: Descriptions are shown in the official language in which they were submitted.
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
TOPOLOGICALLY TAILORED SPUTTERING TARGETS
FIELD OF THE INVENTION
The field of the invention is sputtering targets for physical vapor deposition
(PVD).
S BACKGROUND
Electronic and semiconductor components are used in ever increasing numbers of
consumer
and commercial electronic products, communications products and data-exchange
products.
Examples of some of these consumer and commercial products are televisions,
computers, cell
phones, pagers, palm-type organizers, portable radios, car stereos, or remote
controls. As the
demand for these consumer and commercial electronics increases, there is also
a demand for those
same products to become smaller and more portable for the consumers and
businesses.
As a result of the size decrease in these products, the components that
comprise the products
must also become smaller and/or thinner. Examples of some of those components
that need to be
reduced in size or scaled down are microelectronic chip interconnections,
semiconductor chip
components, resistors, capacitors, printed circuit or wiring boards, wiring,
lceyboards, touch pads,
and chip packaging.
When electronic and semiconductor components are reduced in size or scaled
down, any
defects that are present in the larger components are going to be exaggerated
in the scaled down
components. Thus, the defects that are present or could be present in the
larger component should
be identified and corrected, if possible, before the component is scaled down
for the smaller
electronic products.
In order to identify and correct defects in electronic, semiconductor and
communications
components, the components, the materials used and the manufacturing processes
for malting those
components should be brolcen down and analyzed. Electronic, semiconductor and
communication/data-exchange components are composed, in some cases, of layers
of materials, such
as metals, metal alloys, ceramics, inorganic materials, polymers, or
organometallic materials. The
layers of materials are often thin (on the order of less than a few tens of
angstroms in thickness). In
order to improve on the quality of the layers of materials, the process of
forming the layer - such as
1
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
physical vapor deposition of a metal or other compound - should be evaluated
and, if possible,
improved.
In a typical physical vapor deposition (PVD) process, a sample or target is
bombarded with .
an energy source such as a plasma, laser or ion beam, until atoms are released
into the surrounding
atmosphere. The atoms that are released from the sputtering target travel
towards the surface of a
substrate (typically a silicon wafer) and coat the surface forming a thin film
or layer of a material. A
standard PVD target configuration tends to produce "center-thiclc" and "edge-
thin" deposits because
of a cosine distribution of sputtered atoms. (see Prior Art Figure 1 and US
5,302,266; US
5,225,393; US 4,026,787; and US 3,884,787). Prior Art Figure 1 shows a
conventional PVD
arrangement comprising a sputtering target 10 and a wafer or substrate 20.
Atoms are released from
the sputtering target 10 and travel on an ion/atom path 30 towards the wafer
or substrate 20, where
they are deposited in a layer. .
Several methods and devices have been suggested to correct a large cosine
distribution of
sputtered atoms in order to deposit a more uniform metal film. One popular
method is to physically
place or mount a separate collimator or similar type of aperture between the
target and the surface,
wafer or substrate. (see Prior Art Figure 2 and US 5,409,587; US 4,923,585)
The collimator is
designed to reduce the number of metal atoms hitting the substrate or wafer at
large angles, while
allowing the metal atoms traveling at smaller angles to pass and deposit on
the substrate or wafer,
which reduces the buildup on the top of the contact and via, and increases the
fraction of atoms that
land in the bottom and side wall of the contact or via. Prior Art Figure 2
shows a conventional
PVD arrangement comprising a sputtering target 110, a wafer or substrate 120
and a separate
collimator 140. Atoms are released from the sputtering target 110 and travel
on an ion/atom path
130 towards the wafer or substrate 120, where the atoms are "screened" by the
collimator 140. The
atoms that pass the collimator 140 are deposited in a layer on the wafer or
substrate 120.
Adding a collimator to the target/substrate assembly, however, significantly
increases the
expense of a target material and also reduces the target life because atoms
traveling at high angles
are deposited on the collimator instead of the wafer, and thus, are
effectively wasted in the process.
Also, adding a collimator requires a larger target-to-wafer spacing than that
in the standard
(collimator-free) process to accommodate the collimator and to prevent a
collimator-shaped pattern
formation on the wafer. Moreover, the stray atoms deposited on the collimator
tend to choke up the
2
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
collimator, further decreasing the efficiency of deposition and often causing
an undesirable
particulate formation when the deposits flake off of the collimator surface.
Another method of attempting to create more uniform deposits is to ionize the
sputtered
atoms by applying radio-frequency (RF) power to the plasma (ionized metal
plasma (IIVVIP) process).
(see US 6,296,743) In this process, all exposed surfaces in the RF plasma
develop a negative
potential with respect~to the plasma because of the higher mobility of the
electrons relative to the
heavier ions. Thus the metal ions are attracted to the wafer surface by the
direct current (DC) self
bias even without a pedestal or surface bias. These perpendicularly-traveling
metal ions usually hit
the bottom of the contacts or vies and improve the bottom and side wall
coverage. However, the RF
plasma apparatus and operating conditions contribute to a substantial increase
in system cost and
operational complexity. RF plasma configurations have also been combined with
magnets to further
adjust the path of atoms traveling toward the substrate or wafer, however,
these methods can be cost
prohibitive and difficult to arrange and monitor. (see US 6,153,061; US
6,326,627; US 6,117,281;
US 5,865,969; US 5,766,426; US 5,417,833; US 5,188,717; US 5,135,819; US
5,126,029; US
5,106,821; US 4,500,409; US 4,414,086; US 4,610;770; and US 4,629,548)
Other methods of improving the sputtering process to produce more uniform
films have been
developed. For example, Honeywell Electronic MaterialsTM (HEM) demonstrated
that sputtering
characteristics of a target could be improved substantially by using a
superfine grain size target,
which are produced by the patented technology of the Equal-Channel Angular
Extrusion (ECAE~)
process ( 5,590,389; 5,780,755; and 5,809,393). The demonstratedbenefits
include low arcing, long
target life, high device yield, better film uniformity, and low particulate.
Honeywell Electronic
MaterialsTM has also demonstrated that the crystallographic texture of the
target can be modified-in
a non-pattern-forming fashion - to provide collimating benefits. (see US
5,993,621 and US
6,302,977). The self ionization plasma (SIP) has also been reviewed as a
sputtering process that
could produce :more uniform films. This process utilizes low pressure and high
power to promote
self ionization of sputtered target atoms. SIP requires an extended target-to-
substrate spacing, which
creates a long ion path. The long ion path improves a directionality of ion
flux but again reduces the
target yield. The extended ion path length results in further increased cosine
loss and making it quite
inefficient in target usage. Additional methods include mechanically adjusting
the wafer or
substrate during the sputtering process (US 6,224,718); maslcing part of the
surface (US 5,894,058;
3
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
US 5,942,356; 6,242,13 8); chemically treating the vapor between the target
and the surface or wafer
(US 6,057,238; US 6,107,688; US 4,793,908; US 6,222,271; and US 6,194,783);
and Laser
sputtering and excitation of the atoms (LTS 5,382,457). With the exception of
the ECAE process, the
other methods require additional mechanical or chemical components to be added
to the basic PVD
process and apparatus, which can increase the cost and complexity of the
apparatus and process.
To this end, it would be desirable to produce a PVD target and target/wafer
assembly that a)
takes advantage of the advantageous minimum depth arrangement; b) lceeps the
overall cost of the
process relatively low in relation to a traditional PVD process; and c) allows
the instrumentation and
apparatus to remain simple relative to a traditional PVD process.
SUMMARY OF THE INVENTION
The aging behavior of a standard target suggests that the direction of
sputtered atoms can be
controlled by modifying the surface morphology or topology of a target. In a
standard target
configuration, sputtered atoms distribute in a wide angle producing a non-
uniform film, mainly
because the center region of the wafer experiences a higher flux of sputtered
atoms than the edge of
the wafer.
Sputtering targets described herein are topologically and morphologically
tailored such that
sputtered atoms impinge directly toward a wafer in a narrow cosine
distribution. In effect, the target
is designed with a built-in collimator. The desired morphology and topography
can be accomplished
by micro (e.g., parabolic dimples) and/or macro scale (e.g., target surface
contour) modification of
the target geometry and topography.
Self collimating sputtering targets may comprise any suitable shape and size
depending on
the application and instrumentation used in the PVD process and any component
capable of being
sputtered in a sputtering chamber. Sputtering targets described herein also
comprise a surface
material and a core material, wherein the surface material is coupled to the
core material. The
surface material and core material may generally comprise the same elemental
malceup or chemical
composition/component, or the elemental makeup and chemical composition of the
surface material
may be altered or modified to be different than that of the core material.
Also, a backing plate may
4
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
be coupled to the core material to provide additional support to the
sputtering target and also to
provide a mounting apparatus for the sputtering target.
The surface material is that portion of the target that is exposed to the
energy source at any
measurable point in time and is also that part of the overall target material
that is intended to produce
atoms that are desirable as a surface coating. Further, the surface material
is that part of the
sputtering target that comprises at least two intentionally-formed
indentations that form a
collimating topography or morphology.
The self collimating sputtering target is formed by a) providing a core
material; b) providing
a surface material; c) coupling the core material to the surface material to
form a sputtering target;
and d) forming at least two intentional indentations, wherein the indentations
form a collimating
topography.
A uniform film or layer is formed on a surface of a component or in order to
form a
component by: a) providing a self collimating sputtering target; b) providing
a surface; c) placing the
surface at a distance from the self collimating sputtering target; d)
bombarding the self collimating
sputtering target with an energy source to form at least one atom; and e)
coating the surface with the
at least one atom.
Sputtering targets described herein can be incorporated into anyprocess or
production design
that produces, builds or otherwise modifies electronic, semiconductor and
communication
components. Electronic, semiconductor and communication components are
generally thought to
comprise any layered component that can be utilized in an electronic-based,
semiconductor-based or
communication-based product. Components described herein comprise
semiconductor chips, circuit
boards, chip packaging, separator sheets, dielectric components of circuit
boards, printed-wiring
boards, touch pads, wave guides, fiber optic and photon-transport and acoustic-
wave-transport
components, any materials made using or incorporating a dual damascene
process, and other
components of circuit boards, such as capacitors, inductors, and resistors.
BRIEF DESCRIPTION OF THE FIGURES
Prior Art Fig. 1 shows a conventional PVD target/surface arrangement.
5
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
Prior Art Fig. 2 shows a conventional PVD target/surface arrangement with a
separate collimator
added to the arrangement.
Fig. 3 graphically shows an embodiment of the present invention.
Fig. 4 graphically shows several embodiments of the present invention.
Fig. 5 shows a contemplated method of forming a self collimating sputtering
target.
Fig. 6 shows a contemplated method of forming a uniform film on a surface.
DETAILED DESCRIPTION
The aging behavior of a target suggests that the direction of sputtered atoms
can be
controlled by modifying the surface morphology or topology of a target. In a
standard target
configuration, sputtered atoms distribute in a wide angle producing a non-
uniform film, mainly
because the center region of the wafer experiences a higher flux of sputtered
atoms than the edge of
the wafer, as illustrated in Prior Art Figure 1. The direction of sputtered
atoms can now be
controlled by modifying the surface morphology and topography of a target.
Specifically, the surface
morphology and topography of a target can be tailored such that sputtered
atoms impinge directly
toward a wafer in a narrow cosine distribution as illustrated in Figure 3.
Figure 3 shows a contemplated PVD arrangement comprising a sputtering target
210, and a
wafer or substrate 220. The sputtering target 210 comprises a surface material
260 and a core
material 270. The surface material 260 comprises intentionally-formed
indentations (in this case
microdimples 250). These intentionally-formed indentations are also formed as
a pattern on the
sputtering target. As used herein, the term "pattern" means any formation of
intentionally-formed
indentations that is repeating, arranged or both repeating and arranged. Atoms
are "pre-screened" by
the microdimples 250 that act as a "built-in collimator", in that they are
bombarded in such a way
that they are manipulated at the time of release to travel a certain ion/atom
path 230. The atoms are
then released from the sputtering target 210 and travel on an ion path 230
towards the wafer or
substrate 220. The desired morphology and topography can be accomplished by
micro (e.g.,
parabolic dimples) and/or macro scale (e.g., target surface contour)
modification of the target
6
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
geometry and topography. A backing plate may be. coupled to the core material
to provide
additional support to the sputtering target and also to provide amounting
apparatus for the sputtering
target.
Sputtering targets contemplated herein comprise any suitable shape and size
depending on
the application and instrumentation used in the PVD process. Sputtering
targets contemplated herein
also comprise a surface material 260 and a core material 270, wherein the
surface material 260 is
coupled to the core material 270. As used herein, the term "coupled" means a
physical attachment
of two parts of matter or components (adhesive, attachment interfacing
material) or a physical and/or
chemical attraction between two parts of matter or components, including bond
forces such as
covalent and ionic bonding, and non-bond forces such as Van der Waals,
electrostatic, coulombic,
hydrogen bonding andlor magnetic attraction. The surface material 260 and core
material 270 may
generally comprise the same elemental makeup or chemical
compositionlcomponent, or the
elemental makeup and chemical composition of the surface material 260 may be
altered or modified
to be different than that of the core material 270. In most embodiments, the
surface material 260 and
the core material 270 comprise the same elemental makeup and chemical
composition. However, in
embodiments where it may be important to detect when the target's useful life
has ended or where it
is important to deposit a mixed layer of materials, the surface material 260
and the core material 270
may be tailored to comprise a different elemental malceup or chemical
composition.
The surface material 260 is that portion of the target 210 that is exposed to
the energy source
at airy measurable point in time and is also that part of the overall target
material that is intended to
produce atoms that are desirable as a surface coating. Further, the surface
material 260 is thatpart of
the sputtering target 210 that comprises at least two intentionally-formed
indentations that form a
collimating topography or morphology. .As used herein, the phrase "collimating
topography" is that
paxt of the surface material 260 of the sputtering target 210 that directly
influences the cosine
distribution of atoms in such a way that the cosine atom distribution is
measurably narrowed over the
atom distribution found where a conventional sputtering target is utilized. In
other words, without
any external factors, such as magnets, chemical additives or masks,. the
incorporation of at least two
intentionally-formed indentations that form a collimating topography can
narrow the conventional
cosine distribution of atoms that would normally be produced from a
conventional sputtering target,
although there may be external factors that are fiuther influencing the
sputtered atoms. The
7
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
difference between a conventional cosine distribution of atoms and a narrowed
cosine distribution of
atoms can be seen in Prior Art Figure 1 and Figure 3, as discussed earlier.
As mentioned, at least two intentionally-formed indentations are formed in the
surface
material 260 of the sputtering target 210 to create a collimating topography
or morphology.
Embodiments that comprise relatively large intentionally-formed indentations
generally comprise
what is referred to as a "macroscale modification". The phrase "macroscale
modification" is used
herein to mean tailoring the target surface in a circular wave contour to
compensate uneven erosion
of a target due to the rotating magnets in a magnetron sputtering system. A
macroscale modification
280 (as shown in Figure 4) in most embodiments will generally comprise
relatively large and
intentionally-formed indentations in the sputtering target 210, such
indentation might resemble a
convex or concave lens or a cone. Embodiments that comprise more than two
relatively small
intentionally-formed indentations generally comprise what are referred to as
"microdimples" 250.
The term "microdimples", as used herein, means those indentations that
comprise an opening that
has a closed loop shape, wherein the shapes include a circle (circular), a
hexagon (hexagonal), a
triangle (triangular), a square, an oval and other curved or straight-edged
closed loops, and will have
an aspect ratio greater than 1:l. Figure 3 shows a cross-section view of
microdimples in a
sputtering target. Figure 4 shows a top view of microdimples 250 and
macroscale modifications
280 in a sputtering target 210. Figure 4 also shows the closed loop shape
concept in sputtering
targets that comprise microdimples 250. It is further contemplated that a
sputtering target may
comprise both a macroscale modification 280 and microdimples 250. Sputtering
targets 4(b) and
4(d) in Figure ~ are targets that comprise both macroscale modifications 280
and microdimples 250.
Macroscale modifications 280 and microdimples 250 may either be formed through
a
molding process when the target is originally produced or by some physical or
mechanical
machining, chemical and/or etching/removal process. It is further contemplated
that the macroscale
modifications 280 could be molded into the target 210 when the target 210 is
initially formed and the
microdimples 250 are etched into the target 210 after it is initially formed,
or vice versa. More
specifically, as shown in Figure 5, the self collimating sputtering target 210
is formed by a)
providing a core material 270 (300); b) providing a surface material 260
(310); c) coupling the core
material 270 to the surface material 260 to form a sputtering target 210
(320); and d) forming at least
two intentional indentations, wherein the indentations form a collimating
topography (330).
8
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
The core material 270 is designed to provide support for the surface material
260 and to
possibly provide additional atoms in a sputtering process or information as to
when a target's useful
life has ended. For example, in a situation where the core material 270
comprises a material
different from that of the original surface material 260, and a quality
control device detects the
presence of core material atoms in the space between the target 210 and the
wafer 220, the target 210
may need to be removed and retooled or discarded altogether because the
chemical integrity and
elemental purity of the metal coating could be compromised by depositing
undesirable materials on
the existing surface/wafer layer. The core material 270 is also that portion
of a sputtering target 210
that does not comprise macroscale modifications 280 or microdimples 250. In
other words, the core
material 270 is generally uniform in structure and shape.
Sputtering targets 210 may generally comprise any material that can be a)
reliably formed
into a sputtering target; b) sputtered from the target when bombarded by an
energy source; and c)
suitable for forming a final or precursor layer on a wafer or surface.
Materials that are contemplated
to make suitable sputtering targets 210 are metals, metal alloys, conductive
polymers, conductive
composite materials, conductive monomers, dielectric materials, hardmaslc
materials and any other
suitable sputtering material. As used herein, the term "metal" means those
elements that are in the
d-block and f block of the Periodic Chart of the Elements, along with those
elements that have
metal-lilce properties, such as silicon. and germanium. As used herein, the
phrase "d-block" means
those elements that have electrons filling the 3d, 4d, Sd, and 6d orbitals
surrounding the nucleus of
the element. As used herein, the phrase "f bloclc" means those elements that
have electrons filling
the 4f and Sf orbitals surrounding the nucleus of the element, including the
lanthanides and the
actinides. Preferred metals include titanium, silicon, cobalt, copper,
niclcel, iron, zinc, vanadium,
zirconium, aluminum and aluminum-based materials, tantalum, niobium, tin,
chromium, platinum,
palladium, gold, silver, tungsten, molybdenum, cerium, promethium, thorium or
a combination
thereof. More preferred metals include copper, aluminum, tungsten, titanium,
cobalt, tantalum,
magnesium, lithium, silicon, manganese, iron or a combination thereof. Most
preferred metals
include copper, aluminum and aluminum-based materials, tungsten, titanium,
zirconium, cobalt,
tantalum, niobium or a combination thereof. Examples of contemplated and
preferred materials,
include ahuninum and copper for superfine grained aluminum and copper
sputtering targets;
aluminum, copper, cobalt, tantalum, zirconium, and titanium for use in 300 mm
sputtering targets;
and aluminum for use in aluminum sputtering targets that deposit a thin, high
conformal "seed" layer
9
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
of aluminum onto surface layers. It should be understood that the phrase "and
combinations thereof
is herein used to mean that there may be metal impurities in some of the
sputtering targets, such as a
copper sputtering target with chromium and aluminum impurities, or there may
be an intentional
combination of metals and other materials that make up the sputtering target,
such as those targets
comprising alloys, borides, carbides, fluorides, nitrides, silicides, oxides
and others.
The term "metal" also includes alloys, metal/metal composites, metal ceramic
composites,
metal polyner composites, as well as other metal composites. Alloys
contemplated herein comprise
gold, antimony, arsenic, boron, copper, germanium, nickel, indium, palladium,
phosphorus, silicon,
cobalt, vanadium, iron, hafnium, titanium, iridium, zirconium, tungsten,
silver, platinum, tantalum,
tin, zinc, lithium, manganese, rhenium, and/or rhodium. Specific alloys
include gold antimony, gold
arsenic, gold boron, gold copper, gold germanium, gold nickel, gold nickel
indium, gold palladium,
gold phosphorus, gold silicon, gold silver platinum, gold tantalum, gold tin,
gold zinc, palladium
lithium, palladium manganese, palladium nickel, platinum palladium, palladium
rhenium, platinum
rhodium, silver arsenic, silver copper, silver gallium, silver gold, silver
palladium, silver titanium,
titanium zirconium, aluminum copper, aluminum silicon, aluminum silicon
copper, aluminum
titanium, chromium copper, chromium manganese palladium, chromium manganese
platinum,
chromium molybdenum, chromium ruthenium, cobalt platinum, cobalt zirconium
niobium, cobalt
zirconium rhodium, cobalt zirconium tantalum, copper nickel, iron aluminum,
iron rhodium, iron
tantalum, chromium silicon oxide, chromium vanadium, cobalt chromium, cobalt
chromium niclcel,
cobalt chromium platinum, cobalt chromium tantalum, cobalt chromium tantalum
platinum, cobalt
iron, cobalt iron boron, cobalt iron chromium, cobalt iron zirconium, cobalt
nickel, cobalt nickel
chromium, cobalt niclcel iron, cobalt nickel hafnium, cobalt niobium hafiiium,
cobalt niobium iron,
cobalt niobium titanium, iron tantalum chromium, manganese iridium, manganese
palladium
platinum, manganese platinum, manganese rhodium, manganese ruthenium, nickel
chromium, nickel
chromium silicon, nickel cobalt iron, niclcel iron, nickel iron chromium,
nickel iron rhodium, nickel
iron zirconium, nickel manganese, niclcel vanadium, tungsten titanium and/or
combinations thereof.
As far as other materials that are contemplated herein for sputtering targets
210, the
following combinations are considered examples of contemplated sputtering
targets 210 (although
the list is not exhaustive): chromium boride, lanthanum boride, molybdenum
boride, niobium
boride, tantalum boride, titanium boride, tungsten boride, vanadium boride,
zirconium boride, boron
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
carbide, chromium carbide, molybdenum carbide, niobium carbide, silicon
carbide, tantalum
carbide, titanium carbide, tungsten carbide, vanadium carbide, zirconium
carbide, aluminum
fluoride, barium fluoride, calcium fluoride, cerium fluoride, cryolite,
lithium fluoride, magnesium
fluoride, potassium fluoride, rare earth fluorides, sodium fluoride, aluminum
nitride, boron nitride,
niobium nitride, silicon nitride, tantalum nitride, titanium nitride, vanadium
nitride, zirconium
nitride, chromium silicide, molybdenum silicide, niobium silicide, tantalum
silicide, titanium
silicide, tungsten silicide, vanadium silicide, zirconium silicide, aluminum
oxide, antimony oxide,
barium oxide, barium titanate, bismuth oxide, bismuth titanate, barium
strontium titanate, chromium
oxide, copper oxide, hafnium oxide, magnesium oxide, molybdenum oxide, niobium
pentoxide, rare
earth oxides, silicon dioxide, silicon monoxide, strontium oxide, strontium
titanate, tantalum
pentoxide, tin oxide, indium oxide, indium tin oxide, lanthanum aluminate,
lanthanum oxide, lead
titanate, lead zirconate, lead zirconate-titanate, titanium aluminide, lithium
niobate, titanium oxide,
tungsten oxide, yttrium oxide, zinc oxide, zirconium oxide, bismuth telluride,
cadmium selenide,
cadmium telluride, lead selenide, lead sulfide, lead telluride, molybdenum
selenide, molybdenum
sulfide, zinc selenide, zinc sulfide, zinc telluride and/or combinations
thereof.
Thin layers or films produced by the sputtering of atoms from targets
discussed herein can be
formed on any number or consistency of layers, including other metal layers,
substrate layers 220
dielectric layers, hardmask or etchstop layers, photolithographic layers, anti-
reflective layers, etc. In
some prefeiTed embodiments, the dielectric layer may comprise dielectric
materials contemplated,
produced or disclosed by Honeywell International, Inc. including, but not
limited to: a) FLARE
(poly(arylene ether)), such as those compounds disclosed in issued patents US
5959157, US
5986045, US 6124421, US 6156812, US 6172128, US 6171687, US 6214746, and
pending
applications 09/197478, 09/538276, 09/544504, 09/741634, 09/651396, 09/545058,
09/587851,
09/618945, 09/619237, 09/792606, b) adamantane-based materials, such as those
shown in pending
application 09/545058 ; Serial PCT/CTSO1/22204 filed October 17, 2001;
PCT/USO1/50182 filed
December 31, 2001; 60/345374 filed December 31, 2001; 60/347195 filed January
8, 2002; and
60/350187 filed January 1 S, 2002;, c) commonly assigned US Patents 5,115,082;
5,986,045; and
6,143,855; and commonly assigned International Patent Publications WO 01/29052
published April
26, 2001; and WO 01/29141 published April 26, 2001; and (d) nanoporous silica
materials and
silica-based compounds, such as those compounds disclosed in issued patents US
6022812, US
6037275, US 6042994, US 6048804, US 6090448, US 6126733, US 6140254, US
6204202, US
11
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
6208014, and pending applications 09/046474, 09/046473, 09/111084, 09/360131,
09/378705,
091234609, 09/379866, 091141287,,09/379484, 09/392413, 09/549659, 09/488075,
09/566287, and
09/214219 all of which are incorporated by reference herein in their entirety
and (e) Honeywell
HOSP~ organosiloxane.
Wafer or substrate 220 may comprise any desirable substantially solid
material. Particularly
desirable substrates 220 would comprise films, glass, ceramic, plastic, metal
or coated metal, or
composite material. In preferred embodiments, the substrate 220 comprises a
silicon or germanium
arsenide die or wafer surface, a packaging surface such as found in a copper,
silver, niclcel or gold
plated leadframe, a copper surface such as found in a circuit board or package
interconnect trace, a
via-wall or stiffener interface ("copper" includes considerations of bare
copper and its oxides), a
polymer-based packaging or board interface such as found in a polyimide-based
flex package, lead
or other metal alloy solder ball surface, glass and polymers such as
polyimides. In more preferred
embodiments, the substrate 220 comprises a material common in the packaging
and circuit board
industries such as silicon, copper, glass, or a polymer.
Substrate layers 220 contemplated herein may also comprise at least two layers
ofmaterials.
One layer of material comprising the substrate layer 220 may include the
substrate materials
previously described. Other layers of material comprising the substrate layer
220 may include layers
of polymers, monomers, organic compounds, inorganic compounds, organometallic
compounds,
continuous layers and nanoporous layers.
As used herein, the term "monomer" refers to any chemical compound that is
capable of
forming a covalent bond with itself or a chemically different compound in a
repetitive manner. The
repetitive bond formation between monomers may lead to a linear, branched,
super-branched, or
three-dimensional product. Furthermore, monomers may themselves comprise
repetitive building
blocks, and when polymerized the polymers formed from such monomers are then
termed
"blockpolymers". Monomers may belong to various chemical classes of molecules
including
organic, organometallic or inorganic molecules. The molecular weight of
monomers may vary
greatlybetween about 40 Dalton and 20000 Dalton. However, especiallywhen
monomers comprise
12
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
repetitive building blocks, monomers may have even higher molecular weights.
Monomers may also
include additional groups, such as groups used for crosslinking.
As used herein, the term "crosslinking" refers to a process in which at least
two molecules, or
two portions of a long molecule, are j oined together by a chemical
interaction. Such interactions may
occur in many different ways including formation of a covalent bond, formation
of hydrogen bonds,
hydrophobic, hydrophilic, ionic or electrostatic interaction. Furthermore,
molecular interaction may
also be characterized by an at least temporary physical connection between a
molecule and itself or
between two or more molecules.
Contemplated polymers may also comprise a wide range of functional or
structural moieties,
including aromatic systems, and halogenated groups. Furthermore, appropriate
polymers may have
many configurations, including a homopolymer, and a heteropolymer. Moreover,
alternative
polymers may have various forms, such as linear, branched, super-branched, or
three-dimensional.
The molecular weight of contemplated polymers spans a wide range, typically
between 400 Dalton
and 400000 Dalton or more.
Examples of contemplated inorganic compounds are silicates, aluminates and
compounds
containing transition metals. Examples of organic compounds include
polyarylene ether, polyimides
and polyesters. Examples of . contemplated organometallic compounds include
poly(dimethylsiloxane), poly(vinylsiloxane) and poly(trifluoropropylsiloxane).
The substrate layer 220 may also comprise a plurality of voids if it is
desirable for the
material to be nanoporous instead of continuous. Voids are typically
spherical, but may alternatively
or additionally have any suitable shape, including tubular,.lamellar,
discoidal, or other shapes. It is
also contemplated that voids may have any appropriate diameter. It is further
contemplated that at
least some of the voids may connect with adjacent voids to create a structure
with a significant
amount of connected or "open" porosity. The voids preferably have a mean
diameter of less than 1
micrometer, and more preferably have a mean diameter of less than 100
nanometers, and still more
preferably have a mean diameter of less than 10 nanometers. It is further
contemplated that the
voids may be uniformly or randomly dispersed within the substrate layer. In a
preferred
. embodiment, the voids are uniformly dispersed within the substrate layer
220.
13
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
Contemplated benefits of producing and using self collimating or topologically
tailored
sputtering targets 210 include simplicity of design, low relative cost, a
built-in collimator, better step
coverage, and longer relative target life, among other benefits.
S APPLICATIONS
Sputtering targets 210 described herein can be incorporated into any process
or production
design that produces, builds or otherwise modifies electronic, semiconductor
and
cormnunicatioudata transfer components. Electronic, semiconductor and
communication
components as contemplated herein, are generally thought to comprise any
layered component that
can be utilized in an .electronic-based , semiconductor-based or communication-
based product.
Contemplated components comprise micro chips, circuit boards, chip packaging,
separator sheets,
dielectric components of circuit boards, printed-wiring boards, touch pads,
wave guides, fiber optic
and photon-transport and acoustic-wave-transport components, any materials
made using or
incorpor ating a dual damascene process, and other components of circuit
boards, such as capacitors,
inductors, and resistors.
Electronic-based, semiconductor-based and communications-based/data transfer-
based
products can be "finished" in the sense that they are ready to be used in
industry or by other
consumers. Examples of finished consumer products are a television, a
computer, a cell phone, a
pager, a palm-type organizer, a portable radio, a car stereo, and a remote
control. Also contemplated
are "intermediate" products such as circuit boards, chip packaging, and
keyboards that are potentially
utilized in finished products.
Electronic, semiconductor and communication/data transfer products may also
comprise a
prototype component, at any stage of development from conceptual model to
final scale-up mock-up.
A prototype may or may not contain all of the actual components intended in a
finished product, and
a prototype may have some components that are constructed out of composite
material in order to
negate their initial effects on other components while being initially tested.
A method of forming a uniform film or layer on a surface of a component or in
order to form
a component comprises: a) providing a self collimating sputtering target 400;
b) providing a surface
410; c) placing the surface at a distance from the self collimating sputtering
target 420; d)
14
CA 02433033 2003-06-23
WO 03/000950 PCT/US02/06146
bombarding the self collimating sputtering target with an energy source to
form at least one atom
430; and e) coating the surface with the at least one atom 440, as shown in
Figure 6. The self
collimating sputtering target comprises the sputtering target 210 described
herein that further
comprises a surface material 260 and a core material 270, wherein the surface
material 260
comprises at least two indentations that form a collimating topography. The
surface provided . is
contemplated to be any suitable surface, as discussed herein, including a
wafer, substrate, dielectric
material, hardmaslc layer, other metal, metal alloy or metal composite layer,
antireflective layer or
any other suitable layered material. The distance between the self collimating
sputtering target 210
and the surface 220 is contemplated herein to comprise. any suitable distance
already utilized in
conventional PVD experimental arrangements. The coating, layer or film that is
produced on the
surface may also be any suitable or desirable thickness -ranging from one atom
or molecule thick
(less than 1 nanometer) to millimeters in thickness.
Thus, specific embodiments and applications of topologically modified
sputtering targets
have been disclosed. It should be apparent, however, to those slcilled in the
art that many more
modifications besides those already described are possible without departing
from the inventive
concepts herein. The inventive subj ect matter, therefore, is not to be
restricted except in the spirit of
the appended claims. Moreover, in interpreting both the specification and the
claims, all terms
should be interpreted in the broadest possible manner consistent with the
context. In particular, the
terms "comprises" and "comprising" should be interpreted as referring to
elements, components, or
steps in a non-exclusive manner, indicating that the referenced elements,
components, or steps may
be present, or utilized, or combined with other elements, components, or steps
that are not expressly
referenced.
