Cleaning and liquid contact with solids – Processes – Including application of electrical radiant or wave energy...
Reexamination Certificate
2000-10-13
2002-08-27
VerSteeg, Steven H. (Department: 1753)
Cleaning and liquid contact with solids
Processes
Including application of electrical radiant or wave energy...
C204S192120, C204S298310, C204S298090, C204S248000
Reexamination Certificate
active
06439244
ABSTRACT:
BACKGROUND OF THE INVENTION
(1) Field of the Invention
This invention relates to an apparatus and method for sputter cleaning and more specifically to an apparatus and method for sputter cleaning wherein the temperature of the pedestal on which a substrate to be cleaned is placed is controlled by flowing cooling liquid through the pedestal.
(2) Description of the Related Art
In a conventional sputter cleaning system a wafer, or other substrate, is placed on a layer of insulating material formed over a pedestal formed of conducting metal.
FIG. 1
shows a top view and
FIG. 2
a cross section view of a conventional wafer and pedestal arrangement.
FIG. 2
shows a pedestal
10
having a layer of first insulating material
14
formed thereon. A layer of second insulating material
12
is formed on the sidewall and bottom of the pedestal
10
. A wafer
16
, or other substrate to be sputter cleaned, is placed on the layer of first insulating material
14
. Silicon pins
32
extend through the second insulator
12
into the pedestal
14
to act as a radio frequency power antenna. Substrate extraction holes
42
provide for rods to be inserted to remove the substrate
16
after the cleaning has been completed.
FIG. 1
shows the top view of the pedestal and wafer arrangement. The cross section view shown in
FIG. 2
is taken along line
2
-
2
′ of FIG.
1
.
The wafer
16
, shown in
FIGS. 1 and 2
, is insulated from the metal pedestal
10
by the layer of first insulating material
14
and the pedestal
10
is insulated by the second insulator
12
so that during sputter cleaning of the wafer
16
the wafer temperature can become very high. This elevated wafer temperature has undesirable effects for later processing steps.
U.S. Pat. No. 6,077,353 to Al-Sharif et al. describes a pedestal insulator for a pre-clean chamber.
U.S. Pat. No. 6,033,482 to Parkhe describes a method for lighting a plasma in a plasma processing chamber, showing a plasma chamber with a pedestal.
U.S. Pat. No. 6,081,414 to Flanigan et al. describes apparatus for biasing and retaining a workpiece in a processing system. The apparatus includes a pedestal, a puck, and an electrode between the pedestal and the puck. The puck is an electrostatic chuck to hold the workpiece. The electrode can serve as a cooling plate for the puck.
U.S. Pat. No. 6,090,246 to Leiphart describes methods and apparatus for detecting neutral gas molecules reflected from a target during sputter deposition. Leiphart describes, but does not show, a cooling device, such as a water cooled backing plate to cool the target material during the sputtering process.
U.S. Pat. No. 6,077,404 to Wang et al. describes a method and apparatus for reflowing a material layer.
SUMMARY OF THE INVENTION
In a sputter cleaning system a pedestal
10
, formed of conductive metal, forms a conductive surface below the wafer
16
so that the sputter cleaning can be accomplished, see FIG.
2
. The wafer
16
is insulated from the conductive pedestal
10
by a layer of first insulating material
16
, see FIG.
2
. In this arrangement the temperature of the pedestal and wafer rise with continued cleaning because there is no path to remove the heat energy from the pedestal and wafer. This temperature rise can cause processing problems. Specifically in deposition of a layer of Ti/Al/TiN excessive temperature during cleaning will promote the formation of TiAl
3
which can result in void formation in the structure.
It is a principle objective of this invention to provide a method of sputter cleaning a substrate, such as a wafer, where the pedestal is cooled and the temperature of the pedestal is controlled.
It is another principle objective of this invention to provide an apparatus for cooling the pedestal and controlling the temperature of the pedestal during sputter cleaning of a substrate, such as a wafer.
These objective are achieved by forming a cooling channel in the metal pedestal. The cooling channel is made up of pipes for flowing cooling liquid, such as water. Any form of pipes can be used such as concentric, radial, or other appropriate shape for directing the cooling liquid. An inlet tube delivers a cooling liquid, such as water, to the cooling channel and an exhaust tube removes the cooling liquid from the cooling channel thereby removing heat from the pedestal.
REFERENCES:
patent: 4620081 (1986-10-01), Zeren
patent: 4842683 (1989-06-01), Cheng et al.
patent: 5391275 (1995-02-01), Mintz
patent: 5817577 (1998-10-01), Ko
patent: 6033482 (2000-03-01), Parkhe
patent: 6077353 (2000-06-01), Al-Sharif et al.
patent: 6077404 (2000-06-01), Wang et al.
patent: 6081414 (2000-06-01), Flanigan et al.
patent: 6090246 (2000-07-01), Leiphart
Chapman, B., “Glow Discharge Processes Sputtering and Plasma Etching”, pp. 253-255 (1980).
Ackerman Stephen B.
Prescott Larry J.
ProMos Technologies Inc.
Saile George O.
VerSteeg Steven H.
LandOfFree
Pedestal design for a sputter clean chamber to improve... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Pedestal design for a sputter clean chamber to improve..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Pedestal design for a sputter clean chamber to improve... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2880362