Title: Single workpiece processing system
Abstract: A system and method for processing a workpiece, includes workpiece processors. A robot is moveable within an enclosure to load and unload workpieces into and out of the processors. A processor includes an upper rotor having a central air flow opening. The upper rotor is magnetically driven into engagement with a lower rotor to form a workpiece processing chamber. A moveable drain mechanism aligns different drain paths with the processing chamber so that different processing fluids may be removed from the processing chamber via different drain paths. A moveable nozzle positioned in the air flow opening distributes processing fluid to the workpiece. The processing fluid is distributed across the workpiece surface, via centrifugal force generated by spinning the processing chamber, and removed from the processing chamber via the moveable drain mechanism.
Patent Number: 6,930,046 Issued on 08/16/2005 to Hanson, et al.
| Inventors:
|
Hanson; Kyle M. (Kalispell, MT);
Lund; Eric (Kent, WA);
Grove; Coby (Whitefish, MT);
Peace; Steven L. (Whitefish, MT);
Wirth; Paul Z. (Columbia Falls, MT);
Bruner; Scott A. (Kalispell, MT);
Kuntz; Jonathan (Kalispell, MT)
|
| Assignee:
|
Semitool, Inc. (Kalispell, MT)
|
| Appl. No.:
|
690864 |
| Filed:
|
October 21, 2003 |
| Current U.S. Class: |
438/694; 438/906; 438/907; 438/913; 438/780; 438/782; 134/1.3 |
| Intern'l Class: |
H01L 021/31.1 |
| Field of Search: |
438/694,906-913,780-782,758
134/153-57,199,902,13
118/723
|
References Cited [Referenced By]
U.S. Patent Documents
| 4544446 | Oct., 1985 | Cady.
| |
| 5613343 | Mar., 1997 | Inoue et al.
| |
| 6309520 | Oct., 2001 | Woodruff et al.
| |
| 6334937 | Jan., 2002 | Batz, Jr. et al.
| |
| 6423642 | Jul., 2002 | Peace et al.
| |
| 6548411 | Apr., 2003 | Wirth et al.
| |
| 2002/0017237 | Feb., 2002 | Wirth et al.
| |
| 2002/0168863 | Nov., 2002 | Aegerter et al.
| |
| 2003/0136431 | Jul., 2003 | Scranton et al.
| |
| 2003/0176067 | Sep., 2003 | Wirth et al.
| |
| 2004/0129302 | Jul., 2004 | Hanson et al.
| |
| Foreign Patent Documents |
| WO 99/4606/5 | Sep., 1999 | WO.
| |
Primary Examiner: Zarneke; David
Assistant Examiner: Lee; Granvill
Attorney, Agent or Firm: Perkins Coie LLP
Parent Case Text
This Application is a Continuation-In-Part of U.S. patent application Ser. No.
10/202,074, filed Jul. 23, 2002 now U.S. Pat. No. 6,794,291 and now pending, which
is a Continuation of U.S. patent application Ser. No. 09/437,711, filed Nov. 10,
1999, now U.S. Pat. No. 6,423,642, which is a Continuation-In-Part and U.S. National
Phase of: International Patent Application No. PCT/US99/05676, filed Mar. 15, 1999,
published in English and designating the United States, and claiming priority to
U.S. patent application Ser. No. 60/116,750 filed Jan. 22, 1999. Priority to these
Applications is claimed under 35 U.S.C. 119, 120 and/or 365. These Applications
are also incorporated herein by reference.
Claims
1. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor having a through air flow opening with a diameter which is about
from 20 to 80% of the diameter of the workpiece;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
2. The system of claim 1 further comprising an upper fluid applicator extending
into the through opening in the upper rotor, to provide a processing fluid to an
upper surface of the workpiece.
3. The system of claim 2 further comprising an actuator for moving the upper
fluid applicator within the through opening for distributing a processing fluid
to different portions of the workpiece.
4. The system of claim 3 wherein the upper fluid applicator comprises a nozzle
having a collection section for collecting processing fluid when fluid delivery
to the upper nozzle is discontinued so that excess processing fluid does not drip
from the upper nozzle into the processing chamber.
5. The system of claim 1 further comprising a lower fluid applicator extending
through the lower rotor for introducing a processing fluid to a lower surface of
a workpiece.
6. The system of claim 1 further comprising a plurality of spacing members for
holding a workpiece between the upper and lower rotor members.
7. The system of claim 1 further comprising a spin motor linked to the lower rotor.
8. The system of claim 7 wherein the spin motor has a maximum rotational velocity
of approximately 4000 rpm.
9. The system of claim 7 wherein the spin motor accelerates from 0 to 1800 rpm
in approximately 2 to 4 seconds.
10. The apparatus of claim 1 further comprising magnet means for engaging the
upper and lower rotors.
11. The system of claim 1 further comprising a sump at a central area of the
lower rotor.
12. The system of claim 1 further comprising a moveable drain assembly including
a plurality of drain paths, with each drain path separately alignable with the
processing chamber by vertically moving the drain assembly.
13. The system of claim 1 further comprising an air supply line in communication
with the processing chamber and having an inlet located vertically above the processing
chamber for delivering clean air into the processing chamber.
14. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor;
a lower rotor engageable with the upper rotor to form a workpiece processing
chamber;
a robot moveable between the processors for loading and unloading workpieces
into and out of the processors; and
a moveable drain assembly including a plurality of separate drain paths, with
each drain path separately alignable with the processing chamber by moving the
drain mechanism to align a single drain path with the processing chamber.
15. The system of claim 14 wherein the lower rotor is at a fixed vertical position,
and the upper rotor and the drain assembly are moveable vertically, relative to
the lower rotor.
16. The system of claim 14 wherein the upper rotor has a central through opening
for air flow having a diameter of 20-80% of the diameter of the workpiece.
17. The system of claim 14 further comprising a nozzle extending into the upper
rotor for introducing a processing fluid to an upper surface of a workpiece.
18. The system of claim 14 further comprising a loading station, with the robot
moveable from the loading station to one or more of the workpiece processors.
19. The system of claim 14 wherein the workpiece processors are arranged in a
first row and a second row, with the robot moveable between the two rows.
20. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor having a first magnetic element;
a lower rotor having a second magnetic element, with the upper rotor engageable
to the lower rotor via interaction of the magnetic elements, to form a workpiece
processing chamber; and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
21. The system of claim 20 with the upper rotor having a through opening with
a diameter which is 20-80% of the diameter of the workpiece.
22. The system of claim 20 further comprising an upper fluid applicator extending
into the through opening in the upper rotor, to provide a processing fluid to an
upper surface of the workpiece.
23. The system of claim 20 further comprising an actuator for moving the upper
fluid applicator within the through opening for distributing a processing fluid
to different portions of the workpiece, and for moving the upper fluid applicator
vertically and radially out of the processing chamber.
24. The system of claim 20 further comprising a lower fluid applicator extending
through the lower rotor for introducing a processing fluid to a lower surface of
a workpiece.
25. The system of claim 20 further comprising a moveable drain assembly including
a plurality of drain paths, with each drain path separately alignable with the
processing chamber by vertically moving the drain assembly.
26. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
a first rotor;
a second rotor
engagement means for engaging the first rotor to the second rotor, without the
need for physical contact with the first rotor; and
loading means for loading a workpiece into and out of one or more of the processors.
27. The system of claim 26 wherein the engagement means comprises elements for
creating magnetic repulsion or attraction between the first and second rotors.
28. The system of claim 26 further comprising drain means for separately draining
fluids from the processing chamber.
29. A method of processing a workpiece, comprising the steps of:
placing the workpiece into a first rotor;
engaging a second rotor to the first rotor via a non-contact force, to form a
processing chamber around the workpiece;
spinning the first and second rotors; and
applying a first processing fluid to a first side of the workpiece, with the
first processing fluid flowing radially outwardly over the first side of the workpiece
via centrifugal force.
30. The method of claim 29 further comprising the step of removing the first
processing fluid from the processing chamber via a first drain path located in
a moveable drain mechanism in communication with the processing chamber.
31. The method of claim 29 wherein the non-contact force comprises magnetic force.
32. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
a moveable drain assembly alignable with the processing chamber, the drain assembly
separated from the processing chamber by a gap in which a downward airflow is created
when the drain assembly is lowered and/or the upper rotor is raised; and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
33. The system of claim 32 wherein the gap is 0.125 to 0.250 inches wide.
34. A workpiece processor, comprising:
an upper rotor having a through air flow opening;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
wherein the through air flow opening in the upper rotor has a diameter which
is 20-80% of the diameter of the workpiece.
35. The processor of claim 34 further comprising an upper fluid applicator extending
into the through opening in the upper rotor, to provide a processing fluid to an
upper surface of the workpiece.
36. The processor of claim 35 further comprising an actuator for moving the upper
fluid applicator within the through opening.
37. The processor of claim 35 wherein the upper fluid applicator comprises a
nozzle having a collection section for collecting processing fluid when fluid delivery
to the upper nozzle is discontinued so that excess processing fluid does not drip
from the upper nozzle into the processing chamber.
38. The processor of claim 34 further comprising a lower fluid applicator extending
through the lower rotor for introducing a processing fluid to a lower surface of
a workpiece.
39. The processor of claim 34 further comprising one or more magnets for engaging
the upper and lower rotors.
40. The processor of claim 34 further comprising a moveable drain assembly including
a plurality of drain paths, with each drain path separately alignable with the
processing chamber by vertically moving the drain assembly.
41. A workpiece processor, comprising:
an upper rotor having a first magnetic element;
a lower rotor having a second magnetic element, with the upper rotor engageable
to the lower rotor via interaction of the magnetic elements, to form a workpiece
processing chamber; and
fluid inlet extending into the processing chamber to provide a processing fluid
onto a workpiece in the processing chamber.
42. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor having an opening with an area of about 4% to 64% of the area
of the workpiece;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
43. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor having a through opening;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
a spin motor linked to the lower rotor; and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
44. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor having a through opening;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
a sump at a central area of the lower rotor; and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
45. The system of claim 44 wherein the area of the opening is from about 4% to
64% of the area of the workpiece.
46. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
an upper rotor having a through air flow opening;
a lower rotor engageable to the upper rotor to form a workpiece processing chamber;
an air supply line in communication with the processing chamber and having an
inlet located vertically above the processing chamber for delivering clean air
into the processing chamber; and
a robot moveable between the workpiece processors for loading and unloading a
workpiece into and out of one or more processors.
47. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
a first rotor;
a second rotor
engagement means for engaging the first rotor to the second rotor, without the
need for physical contact with the first rotor, with the engagement means including
elements for creating magnetic repulsion or attraction force on a rotor; and
loading means for loading a workpiece into and out of one or more of the processors.
48. A system for processing a workpiece, comprising:
a plurality of workpiece processors, with at least one of the workpiece processors
comprising:
a first rotor;
a second rotor
engagement means for engaging the first rotor to the second rotor, without the
need for physical contact with the first rotor;
drain means for separately draining fluids from the processing chamber; and
loading means for loading a workpiece into and out of one or more of the processors.
49. The system of claim 48 wherein the engagement means comprises elements for
creating magnetic repulsion or attraction on the first or second rotor.
50. A workpiece processor, comprising:
a base housing;
a base magnet on the base housing;
a first rotor rotatable within the base housing;
a second rotor adapted to engage and form a processing chamber with the first
rotor;
a rotor magnet on the first rotor, with the rotor magnet repelled by the base
magnet.
51. The system of claim 50 further comprising means for spinning the first rotor,
with the first rotor making no physical contact with the housing while spinning.
52. The system of claim 50 where the base magnet, or the rotor magnet, or both,
comprise a magnet ring.
53. A workpiece processor, comprising:
a fixed, non-rotating housing;
at least one housing magnet on the housing;
a first rotor rotatable within the housing;
at least one rotor magnet on the first rotor;
a second rotor engageable with the first rotor;
and with first rotor biased away from the housing via the rotor magnet repelling
the housing magnet.
54. The workpiece processor of claim 53 with the first rotor suspendable within
the housing via interaction between the housing magnet and the rotor magnet.
55. The workpiece processor of claim 53 further comprising a through air flow
opening in the second rotor, with the through air flow opening having a diameter
of from about 20-80% of the diameter of the workpiece.
56. The workpiece processor of claim 53 further comprising a fluid applicator
extendible through the through air flow opening in the second rotor.
57. The workpiece processor of claim 53 further comprising a drain assembly vertically
moveable relative the first rotor.
58. A workpiece processor, comprising:
an upper rotor having a through air flow opening with a diameter which is about
from 20 to 80% of the diameter of the workpiece; and
a lower rotor engageable to the upper rotor to form a workpiece processing chamber.
59. The processor of claim 58 further comprising an upper fluid applicator extending
into the through opening in the upper rotor, to provide a processing fluid to an
upper surface of a workpiece in the processing chamber.
60. The processor of claim 59 comprising an actuator for moving the upper fluid
applicator within the through opening for distributing a processing fluid to different
portions of the workpiece.
61. The processor of claim 59 wherein the upper fluid applicator comprises a
nozzle having a collection section for collecting processing fluid when fluid delivery
to the upper nozzle is discontinued so that excess processing fluid does not drip
from the upper nozzle into the processing chamber.
62. The processor of claim 58 further comprising a lower fluid applicator extending
through the lower rotor for introducing a processing fluid to a lower surface of
a workpiece in the processing chamber.
63. The processor of claim 58 further comprising a spin motor linked to the lower rotor.
64. The processor of claim 58 further comprising magnet means for engaging the
upper and lower rotors.
65. The processor of claim 58 further comprising a sump at a central area of
the lower rotor.
66. The processor of claim 58 further comprising a moveable drain assembly including
a plurality of drain paths, with each drain path separately alignable with the
processing chamber by vertically moving the drain assembly.
67. A workpiece processor, comprising:
an upper rotor;
a lower rotor engageable with the upper rotor to form a workpiece processing
chamber; and
a moveable drain assembly including a plurality of separate drain paths, with
each drain path separately alignable with the processing chamber by moving the
drain mechanism to align a single drain path with the processing chamber.
68. The processor of claim 67 wherein the lower rotor is at a fixed vertical
position, and the drain assembly is moveable vertically, relative to the lower rotor.
69. The system of claim 67 wherein the upper rotor has a central through opening
for air flow having a diameter of 20-80% of the diameter of the workpiece.
70. A workpiece processor, comprising:
an upper rotor having a first magnetic element;
a lower rotor having a second magnetic element, with the upper rotor engageable
to the lower rotor via interaction of the magnetic elements, to form a workpiece
processing chamber.
71. The processor of claim 70 with the processing chamber adapted for processing
a workpiece having a specific diameter, and with the upper rotor having a through
opening with a diameter which is 20-80% of the diameter of the workpiece.
72. The processor of claim 70 further comprising an upper fluid applicator extending
into the through opening in the upper rotor, to provide a processing fluid to an
upper surface of the workpiece.
73. The processor of claim 70 further comprising an actuator for moving the upper
fluid applicator within the through opening for distributing a processing fluid
to different portions of the workpiece, and for moving the upper fluid applicator
out of the processing chamber.
74. The processor of claim 70 further comprising a lower fluid applicator extending
through the lower rotor for introducing a processing fluid to a lower surface of
a workpiece.
75. The processor of claim 70 further comprising a moveable drain assembly including
a plurality of drain paths, with each drain path separately alignable with the
processing chamber by vertically moving the drain assembly.
76. A workpiece processor, comprising:
a first rotor;
a second rotor; and
engagement means for engaging the first rotor to the second rotor, without the
need for physical contact with the first rotor.
77. The processor of claim 76 wherein the engagement means comprises elements
for creating magnetic repulsion or attraction between the first and second rotors.
78. The processor of claim 76 further comprising drain means for separately draining
fluids from the processing chamber.
79. A workpiece processor, comprising:
an upper rotor;
a lower rotor engageable with the upper rotor to form a processing chamber;
an opening in the lower rotor; and
a snorkel having a first end vertically above the upper rotor, and having a second
end leading to the opening in the lower rotor.
80. The processor of claim 79 further comprising a nozzle arranged to spray a
process liquid through the opening in the lower rotor and onto a lower surface
of a workpiece in the processing chamber, a tube connecting to the nozzle and to
the second end of the snorkel, and a valve associated with the snorkel or the tube.
81. A workpiece processor, comprising:
an upper rotor;
a lower rotor engageable with the upper rotor;
a sump section on the lower rotor; and
a nozzle extending up at least partially through the sump section.
82. The processor of claim 81 wherein the sump section comprises a conical depression
around the center of the lower rotor.
Description
BACKGROUND OF THE INVENTION
Microelectronic devices are used in a wide array of products. These
devices, such as memory and microprocessor chips and similar devices have traditionally
been used in, for example, computers, telephones, sound equipment and other electronic
products. Over the last several years, microelectronic devices have become faster,
better, and less expensive. Microelectronic devices are accordingly now also used
in traditionally non-electronic products, such as appliances, vehicles, toys and
games, medical devices, novelty items, etc. The remarkable progress made in the
microelectronic device industry has led to better yet less expensive products of
all types. It has also led to entirely new types of products.
A major factor in the development of microelectronic devices has been the machines
and methods used to manufacture them. Manufacturing of microelectronic devices
requires extreme precision, extremely pure materials, and an extremely clean manufacturing
environment. Even tiny particles of dust, dirt, metals, or manufacturing chemicals,
at almost any stage of the manufacturing process, can cause defects and failures
in devices. Reducing contaminants is therefore critical to cost effective manufacturing.
Accordingly, intensive research and development has focused on reducing contaminants
in microelectronic manufacturing processes. As microelectronic devices are made
even smaller, reducing contaminants has become even more important, and more difficult
to achieve. In the past, various approaches have been used to reduce contaminants.
These include use of materials that tend not to generate particles, careful selection
and placement of mechanical components in processing machines, and use of a flow
of highly filtered and clean air or gases, to carry any particles generated away
from the wafers or substrates which form the microelectronic devices. Even though
these techniques have been successful, engineering challenges remain in trying
to further reduce contamination, to provide more reliable and cost effective manufacturing.
As described below, the inventors of this patent application have now designed
new machines and methods which offer significantly improved manufacturing of microelectronic devices.
Manufacturing of microelectronic devices involves using various chemicals.
These chemicals are typically in liquid form, although gases and vapors are also
often used. These chemicals must be highly pure and are therefore expensive. Chemicals
used in some processes, such as strong acids or oxidizers, are also toxic. Use
and disposal of these chemicals after they are used, can be time consuming and
expensive. Consequently, reducing the amount of chemicals used is highly advantageous.
On the other hand, in general, enough of the chemicals must be provided so that
they can be uniformly applied over all surfaces of the wafer or substrate being
processed or manufactured. It can therefore be difficult to minimize chemical consumption,
while maintaining good manufacturing results.
Manufacturing microelectronic devices also uses large amounts of purified
and de-ionized water. After it is used, e.g., for rinsing, the water typically
will have small amounts of dissolved chemicals in it. The water then also often
requires special handling and disposal efforts. Accordingly, reducing the amount
of water used, as well as the amounts of chemicals used, would be highly advantageous.
Another problem that may occur in existing microelectronic device manufacturing
systems is that processing chemicals may be mixed with one another when the chemicals
are drained from the processing chamber, and/or when the chemicals are re-circulated
back to the processing chamber. When processing chemicals are mixed with one another,
disposal of them can be more difficult. Thus, there is a need for a wafer processing
system that can effectively isolate different processing chemistries from one another
during and after wafer or substrate processing.
Another problem in existing wafer-processing systems arises when a nozzle
or other fluid outlet is oriented to spray processing fluid downward onto a wafer.
After the fluid delivery is stopped, some excess processing fluid may drip out
of the nozzle onto the wafer. At certain times, even a few drops of excess fluid
can result in defects or failure of the microelectronic end products. Thus, there
is a need for a wafer processing system that overcomes these disadvantages.
SUMMARY OF THE INVENTION
After extensive research and development, the inventors have created a new
wafer or substrate processing system, which provides dramatic improvements in manufacturing
microelectronic and similar devices. This new system reduces contamination. As
a result, there are fewer defects in the end products. This reduces the total amount
of raw materials, chemicals, water, time, labor and effort required to manufacture
microelectronic devices. Correspondingly, less waste, such as used chemicals and
waste water, are created.
This newly created system also greatly reduces the amount of chemicals and water
needed in manufacturing. By using chemicals and water in new and more efficient
ways, high manufacturing quality standards are achieved, yet with less chemical
and water consumption, when compared with existing systems now in use.
One feature of the invention is a new system that includes an upper rotor that
is engageable with a lower rotor to form a workpiece processing chamber. The upper
rotor has a central air inlet opening. This rotor design provides an air flow path
through the processing chamber which tends to avoid having contaminant particles
contact the workpiece. This improves the manufacturing yield or efficiency of the
system, by reducing defects in the microelectronic or other end products.
Another separate feature of the invention is a fluid applicator or nozzle
moveable within the opening for distributing a processing fluid to different portions
of the workpiece in the processing chamber. A fluid delivery line leading into
the nozzle preferably includes a collection section for collecting processing fluid
when fluid delivery to the nozzle is discontinued. This prevents excess processing
fluid from dripping onto the workpiece. Consequently, manufacturing is more consistent,
and defects are reduced. The nozzle is preferably moveable away from the upper
rotor member so that the upper rotor member may be raised to facilitate loading
of a workpiece into the processing chamber.
In another separate feature of the invention, the upper rotor is magnetically
driven into contact with the lower rotor. A face seal is preferably used to seal
the upper rotor against the lower rotor. This improves the reliability of the system
and also reduces potential for particle generation in the system.
Another separate feature of the invention is a moveable drain assembly having
multiple drain paths. Each drain path is separately alignable with the processing
chamber by moving the drain assembly to align a single drain path with the processing
chamber. As a result, used liquid process chemical can be separately removed, collected,
and either recycled or processed for disposal. Mixing of used liquid process chemicals
is avoided. Processing is therefore less complex and less costly.
Other features and advantages of the invention will appear hereinafter. The
features of the invention described above can be used separately or together, or
in various combinations of one or more of them, with no single feature essential
to the invention. The processor and drain assembly can be used alone, or in a system
with robotic automation. The processor and drain assembly can each be used separately
from each other, or together. The invention resides as well in sub-combinations
of the features described.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, wherein the same reference number denotes the same element,
throughout
the several views:
FIG. 1 is a perspective view of a workpiece processing system including a preferred
workpiece processor.
FIG. 2 is a perspective view of the system shown in FIG. 1, with components
removed for purpose of illustration.
FIG. 3 is a plan view of the system shown in FIG. 1.
FIG. 4 is a perspective view of the processor of FIG. 1 in a load/unload position.
FIG. 5 is a section view of the processor of FIG. 4.
FIG. 6 is a section view of the processor of FIG. 4 with a moveable fluid delivery
tube directed into the processing chamber.
FIG. 7 is a perspective view of the processor of FIGS. 2 and 4 shown in a processing position.
FIG. 8 is a section view of the processor of FIG. 7.
FIG. 9 is a cross-sectional view of the processor of FIG. 7 with a moveable
fluid delivery tube directed into the processing chamber.
FIG. 10 is a cross-sectional view of a fluid delivery line having a fluid collection area.
FIG. 11 is a perspective view of a nozzle or liquid supply outlet having a fluid
collection area.
FIG. 12 is a first cross-sectional view of a drainage system of the processor
of FIGS. 2, 4, and 7.
FIG. 13 is a second cross-sectional view of a drainage system of the processor
of FIGS. 2, 4, and 7.
FIG. 14A is a lower perspective view of the drainage system of FIGS. 12 and 13.
FIG. 14B is an upper perspective view of the drainage system of FIGS. 12
and 13.
DETAILED DESCRIPTION OF THE DRAWINGS
The invention is directed to apparatus and methods for processing a workpiece,
such as a semiconductor wafer. The term workpiece, wafer, or semiconductor wafer
means any flat media or article, including semiconductor wafers and other substrates
or wafers, glass, mask, and optical or memory media, MEMS substrates, or any other
workpiece having micro-electronic, micro-mechanical, or electro-mechanical devices.
As shown in FIG. 1, a processing system
10 has an enclosure
15,
a control/display
17, and an input/output station
19. Wafers or workpieces
24 within pods or boxes
21 are removed from the boxes
21 and
processed within the system
10.
Turning to FIG. 2, the processing system
10 includes a support structure
frame
12 with a plurality of processing stations
14 within the enclosure
15. A workpiece processor
16 is positioned at only one of the processing
stations
14 for purpose of illustration. The workpiece processor
16
may be configured to process workpieces, such as 200 or 300 mm diameter semiconductor
wafers provided within sealed boxes
21, open cassettes, or other carrier
or container.
Referring to FIG. 3, preferably all of the processing stations
14
in the enclosure
15 have a workpiece processor
16. The frame
12
in FIG. 2 is shown having ten workpiece processing stations
14, but any
desired number of processing stations
14 may be included in the enclosure
15. The frame
12 preferably includes a centrally located, longitudinally
oriented space
18 between the processing stations
14. One or more
robots
20 move to load and unload workpieces into and out of the processors
16.
FIGS. 2 and 4 illustrate the workpiece processor
16 in an up, open or
workpiece load/unload position. While in the open position, a workpiece
24
may be loaded and unloaded to and from the processor
16. The robot arm
20,
includes an end effector
22 for loading and unloading a workpiece
24
into and out of the processor
16. In a preferred embodiment, the robot arm
20 is supported on a robot base that moves linearly along a track
23
in the space
18. The robot moves within the enclosure for delivering workpieces
to and from the various processing stations
14. Preferably the processors
16 are arranged in first and second rows as shown in FIG. 3, with first
and second robots
20 loading and unloading workpieces only into processors
in the first and second rows, respectively. However, other designs may also be
used. For example, a single robot may be used to load and unload all processors
16. Alternatively, two robots may be used, with crossover operation, so
that either robot can load and unload any processor
16.
Turing to FIG. 5, the processor
16 includes an upper rotor
26
that is engageable to a lower rotor
28 to form a processing chamber
51
(shown in FIG.
8). In the illustrated embodiment, the workpiece
24
has flat upper and lower surfaces.
The upper rotor
26 is preferably annular with a relatively large central
opening
32. The opening
32 preferably has a diameter that is 20-80%,
30-70%, or 40-60% greater than the diameter of a workpiece
24. For example,
if the processor is configured to process 200 mm diameter wafers, the diameter
of the opening
32 is preferably between 100 and 150 mm in diameter, more
preferably approximately 125 mm in diameter.
One or more pneumatic air cylinders
38 or other actuators are attached
to the support plate
34 for raising and lowering the upper rotor
26
between the open position illustrated in FIGS. 4 and 5, and the closed position
illustrated in FIGS. 7-9.
The lower rotor
28 is preferably fixed in position on a base
40
such that the upper rotor
26 is lowerable to engage or contact the lower
rotor
28 to form the processing chamber
51. In an alternative embodiment,
the lower rotor
28 may be lifted to engage a fixed upper rotor
26,
or the two rotors
26,
28 may be moveable toward one another to form
the process chamber
51.
As shown in FIGS. 5 and 8, workpiece
24 is preferably supported in the
processing chamber on a plurality of lower supports
27 extending upwardly
from the lower rotor
28. Upper support pins
29 on the upper rotor
26 generally tend to limit upward movement of the workpiece off of the lower
supports
27, as illustrated in FIG.
5. The workpiece
24 may
alternatively be secured, as described in U.S. Pat. No. 6,423,642.
Referring to FIG. 5, an annular housing
55 is attached to the plate
34. An annular flange
43 on the upper rotor
26 is located
within an annular slot
53 in the housing
55. A lower magnet ring
57 is attached on top of the flange
43. The upper rotor
26,
the flange
43 and magnet ring
57 form an upper rotor assembly
59
which spins as a unit within the housing
55. The upper rotor
26 preferably
has an inner PVDF or Teflon (Flourine resins) liner
61 attached to a metal,
e.g., stainless steel ring
63, which supports the flange
51. The
lower rotor is also preferably PVDF or Teflon. Three pins
52 extend up at
the perimeter of the lower rotor
28 for engagement or insertion into openings
or receptacles
54 in the upper rotor. The pins
52 have tapered conical
tips to align the upper rotor with the lower rotor, as they are brought together.
The pins
52 also transmit torque from the lower rotor to the upper rotor,
as the rotors spin together as a rotor unit during processing.
Referring still to FIG. 5, a ring plate
67 is attached to the housing
55. The top end of the upper rotor
26 extends up through the ring
plate
67. An upper magnet ring
69 is attached to the ring plate
67.
The upper magnet ring
69 repels the lower magnet ring
57. The ring
plate
67 has a conical section
71 which overlies and is attached
to the plate
34. The plate
34, housing
55, ring plate
67
and conical section
71, and the upper magnet ring
69, form a housing
assembly
73, which moves vertically via the actuators
38, but does
not rotate. Rather, the upper rotor assembly
59 rotates within the stationary
housing assembly
73. As shown in FIG. 5, with the processor
16 in
the open or up position, the flange
43 of the upper rotor assembly
59
rests on the annular lip or ledge
77 of the housing
55, with no other
contact between the rotor assembly
59 and the housing assembly
73.
Anti-clocking pins
58 (FIG. 8) extend up from the lip
77 into the
flange
43 when the processor is in the open or up position, to keep the
upper rotor in angular alignment with the lower rotor.
As shown in FIG. 8, with the processor
16 in the down or closed position,
there is no physical contact between the upper rotor assembly
59 and any
part of the housing
55 or housing assembly
73. The repelling force
of the magnet rings
57 and
69 drives the upper rotor assembly
59
down into contact with lower rotor
28, without physical contact. The magnet
rings
57 and
69 may be replaced by individual magnets, electro-magnets
or other magnetic elements.
Since the upper rotor
26 has no physical or mechanical connection with
the upper rotor
26 or upper rotor assembly
59, and the surrounding
structure, such as the housing
55, plate
67 or plate
34, the
upper rotor
26 can automatically align itself with the lower rotor
28,
when they are brought together. The need for precise alignment of the upper rotor
to the lower rotor is therefore avoided. In addition, as there is no physical contact
between the fixed housing assembly
73 and the rotating rotor assembly
59
during processing, the potential for generating contaminant particles is greatly reduced.
A face seal or other sealing element
31, shown in FIG. 5, may be used
to
form a seal between the upper and lower rotors
26,
28 when they are
brought together. For some applications, no seal is needed. The upper and lower
rotors
26,
28 preferably contact one another only at the seal. The
seal may be located on an interior face of one or both of the rotors
26,
28, and is preferably located around the perimeter of the rotors.
Referring to FIG. 8, when the rotors
26,
28 are brought together,
they form a combined rotor unit
35 rotatable via a motor
39 supported
on a base
40. The motor
39 is contained in a motor housing
37
attached to a base plate
40 or the frame
12. A motor rotor
75
is joined to a backing plate
41 which is attached to and supports the lower
rotor
28. As shown in FIG. 5, the motor rotor
75 has a diameter which
is at least 20, 30, 40, 50, 60, 70, or 80% of the diameter of the workpiece. This
allows for improved dynamic balancing of the system, and less vibration. Turning
back to FIG. 8, a barrier ring
78 forms a tortuous path with the bottom
of the backing plate
41. This helps to reduce migration of any particles
from the motor outwardly and up towards the workpiece. A conical depression at
the center of the lower rotor forms a sump
81 which collects and drains
away stray liquid. Drain outlets
30 extend through the upper rotor, as shown
in FIG.
5.
The large diameter in the motor
39 provides a torque advantage as compared
to conventional motors. As a result, the motor
39 has greater rpm and acceleration
capabilities than typical motors used in workpiece processing systems. For example,
the large bore motor
39 can accelerate from 0 to 1800 rpm in approximately
2 to 4 seconds, as compared to motors used in typical workpiece processing systems
that generally accelerate from 0 to 1800 rpm in approximately 14 to 18 seconds.
Additionally, motors typically used in workpiece processing systems have maximum
rotational velocities of 1800 to 2000 rpm. The large bore motor
39, conversely,
preferably has a maximum rotational velocity of 3800 to 4200 rpm, or approximately
4000 rpm. By using a motor
39 with greater rpm and acceleration capabilities,
the workpiece processing system
10 can dry workpieces more quickly.
When the rotor unit
35 rotates, air is drawn into the processing chamber
51 through the opening or bore
32 in the upper rotor
26. The
opening
32 is large relative to the chamber outlets. This creates a low
pressure differential within the processing chamber. This low pressure differential
results in air flowing into the processing chamber at a low velocity. As a result,
significantly fewer contaminant particles are likely to be drawn into the processing
chamber by the incoming airflow, in comparison to existing designs. This reduces
the chances of the workpiece becoming contaminated.
As illustrated in FIGS. 7-9, an upper nozzle
42 or fluid applying device
can be positioned within the upper rotor
26. The nozzle
42 supplies
one or more processing fluids to an upper surface of the workpiece
24. Additional
nozzles may be provided for separately supplying processing chemicals, rinsing
fluids, and/or drying fluids or gases. Alternatively, a single nozzle
42
may be used to supply all of the fluids required for processing.
The upper nozzle
42 is attached to an end of a relatively inflexible upper
fluid delivery tube or line
44. The upper fluid delivery line
44
is attached to a motorized lifting and rotating mechanism
46, which can
raise and lower, as well as pivot, the upper fluid delivery line
44 and
the upper nozzle or outlet
42 in a back and forth alternating movement.
Additionally, the upper nozzle
42 may be lifted up and out of the upper
rotor
26 and pivoted away for processing steps not requiring a nozzle, or
so that the upper rotor
26 may be raised into the open or workpiece-receiving position.
As illustrated in FIG. 10, upper nozzle
42 may include a fluid collection
area
45. In existing systems, there is a potential for excess fluid to drip
from the upper nozzle onto the workpiece after fluid delivery has been stopped.
This can lead to workpiece contamination or other defects. Suck-back and gas purging
techniques have been used in an attempt to completely empty the fluid delivery
tube, but residual drops often still occur. Thus, the collection area
45
may be used with suck-back or purging techniques, to collect the residual fluid
so that it does not drip into the processing chamber.
The fluid collection area
45 is preferably formed by a first tube section
47 extending upwardly at an angle from the upper fluid delivery line
44.
The fluid collection area
45 is preferably large enough to contain several
drops of fluid. As illustrated in FIG. 11, a nozzle
42 incorporating a collection
area
45 may be manufactured as a separate component that may be attached
to the end of the upper fluid delivery tube or line
44.
As illustrated in FIGS. 5 and 8, a lower nozzle
48 or other fluid delivery
outlet is preferably centrally positioned beneath the workpiece
24 for delivering
one or more processing fluids to a lower surface of the workpiece
24. A
lower fluid delivery tube or line
50 is attached to the lower nozzle
48
for supplying fluid to the lower nozzle
48. The lower fluid delivery line
50 may be supplied with processing fluid from the same or from different
fluid reservoir(s) from which the upper fluid delivery line
44 is supplied.
Thus, the upper and lower surfaces of the workpiece
24 may be processed
simultaneously, or sequentially, with the same or with different processing fluids.
The nozzles
42 and
48 may be spray nozzles or applicators of any
shape or pattern, or they may be simple outlets or openings, to supply a process
liquid or gas or vapor to the workpiece, in any format or condition.
In a preferred embodiment, as illustrated in FIG. 5, an air supply line or snorkel
92 has an inlet or opening
94 located vertically above the processing
chamber
51. Typically, the inlet
94 is near the top of the system
enclosure
15, shown in FIG. 1. A vertical riser section
96 of the
snorkel
92 connects into a horizontal section
98 and into a valve
90, which is joined to the lower fluid line
50. When the rotor assembly
spins, clean air (not recycled air) is drawn through the snorkel
92 and
is supplied to the bottom surface of the workpiece. The low air pressure adjacent
to the center of the spinning rotor assembly draws the clean air in through the
lower nozzle
50. The air sprays upwardly from the lower nozzle
50
onto the lower surface of the workpiece. Drying of the lower surface is therefore
achieved more quickly.
The drain outlets
30 are spaced apart around the perimeter of the upper
rotor
26, as shown in FIG.
5. The drain outlets
30 allow fluid
to exit from the processing chamber
51 via centrifugal force when the rotor
unit
35 spins during processing. The drain outlets
30 alternatively
can be in the lower rotor or on both the upper and lower rotors. The drain outlets
30 can also be provided in other forms, such as a slot or an opening between
the rotors.
As shown in FIGS. 4,
5 and
8, an annular drain assembly
70
is positioned around the rotor unit
35. The drain assembly
70 is
preferably vertically moveable via a lifting mechanism or elevator
72. The
elevator
72 includes an armature
74 attached to the drain assembly
70. A motor
79 turns a jack screw
76 to raise and lower the
armature
74 and the drain assembly
70.
The drain assembly
70 includes a plurality of drain paths that are separately
alignable with the outlets
30 in the processing chamber. Three drain paths
80,
82,
84 are shown in FIGS. 5 and 8, but any desired number
of drain paths may be included in the drain assembly
70. Multiple drain
paths are provided so that different processing liquids (including deionized (DI)
water), may be removed from the processing chamber through separate paths. This
helps to avoid cross-contamination between the processing liquids.
Turning to FIGS. 12-14B, the drain paths
80,
82,
84
each preferably lead to a separate drain tube
80a,
82a,
84a, respectively, which lead out of the processor
16. The
drain assembly
70 also preferably includes an exhaust plenum
88 shown
in FIGS. 12 and 13 which draws in exhaust. Exhaust ports
89 extend through
the drain assembly
70 and connect into the exhaust plenum. An exhaust tube
86 provides an exhaust from the system.
When the upper rotor member
26 is in the open or up position, the drain
assembly
70 is preferably at its lowest position, adjacent to the base
40,
as illustrated in FIGS. 4-6. This allows for loading and unloading of a workpiece
24 into and out of the processor
16, as shown in FIG.
4. When
the upper rotor
26 is lowered into the closed or processing position, the
drain assembly
70 is raised by the elevator
72 to align one of the
drain path
80,
82, or
84 with the outlets
30 in the
processing chamber, as illustrated in FIGS. 7-9.
Processing fluid is removed from the processing chamber
51 through
the outlets
30 via centrifugal force generated by rotation of the rotor
unit
35. The fluid then flows along the drain path that is aligned with
the processing chamber outlets, and continues out of the processor
16 through
the corresponding drain tube. The processing fluid may then be recycled or sent
to a disposal area.
The inner surface of the drain assembly
70 is preferably separated from
the outer surface of the rotor unit
35 by a gap of approximately 0.125 to
0.250 inches, more preferably 0.175 to 0.200 inches. When the drain assembly
70
is lowered and/or when the upper rotor
26 is raised, air flows downward
through the gap toward the system exhaust. This airflow entrains particles and
fluids and pulls them away from the workpiece toward the system exhaust. As a result,
when the drain assembly
70 is lowered, and the upper rotor
26 is
raised to allow access to the workpiece, few, if any, particles and contaminants
are present in the processing chamber. Thus, particle re-deposition on the workpiece
is substantially reduced or eliminated.
In use, a pod, cassette, or container
21 is moved onto the input/output
station
19. If the container is sealed, such as a FOUP or FOSBY containers,
the door is removed, via robotic actuators in the system
10. The robot(s)
20 then remove a workpiece
24 from the container
21 and place
the workpiece
24 in a processor
16, as shown in FIG.
4. The
processor
16 is in the up or open position, and the drain assembly
70
is in the down position, as shown in FIG.
4. While the processor
16
could also be provided as a stand alone manually loaded system (without the loader
19, the robots
20 or the enclosure
15), the automated system
shown in FIGS. 1 and 3 is preferred.
The workpiece
24 is positioned on the workpiece supports
27 on
the lower rotor
28. The upper rotor
26 is then lowered down via the
actuators
38 and engages with the lower rotor member
28 to form a
processing chamber
51 around the workpiece
24. The repulsion of the
magnets or magnet rings
57 and
69 forces the upper rotor against
the lower rotor, with the face seal forming a seal at the perimeter. The spacing
members or support pins
29 on the upper rotor member
26 closely approach
or contact the upper surface of the workpiece
24 to secure or confine the
workpiece in place.
Once the rotor unit
35 is in the closed or processing position, the drain
assembly
70 is raised by the elevator
72 so that it is positioned
around the rotor unit. A drain path
80, for removing the first processing
fluid used to process the workpiece
24, is aligned with the outlets
30.
The spacing between the entrance to the drain paths
80,
82,
84
and the outlets
30 is minimized, so that liquid exiting the outlets
30
moves into the drain paths, rather than running down the sides of the lower rotor.
Alternatively, annular ring seals may be used to help move liquid from the outlets
30 into the drain paths, without dripping or leaking.
After the drain path
80 is properly aligned, a processing fluid is supplied
via one or both of the upper and lower fluid supply tubes
44,
50
to one or both of the upper and lower nozzles or outlets
42,
28,
which deliver the processing fluid to the upper and/or lower surfaces of the workpiece
24. The rotor unit is generally rotated by the motor
39 to generate
a continuous flow of fluid across the surfaces of the workpiece
24 via centrifugal
force. Processing fluid is thus driven across the workpiece surfaces in a direction
radially outward from the center of the workpiece
24 to the edges of the
workpiece
24. The upper nozzle
42 may be moved back and forth within
the bore
32 by the motorized lifting and rotating mechanism
46, to
more evenly distribute processing fluid to the upper workpiece surface.
As the rotor unit rotates, air is drawn into the processing chamber through the
opening
32 in the upper rotor assembly
59 and housing assembly
73.
As the opening
32 is relatively large, and the processing chamber
51
is substantially closed, except at the outlets
30, air flows through the
processing chamber at a relatively low velocity, thus reducing the likelihood of
entraining particles that could contaminate the workpiece. In a preferred embodiment,
the air flowing through the processing chamber is filtered through one or more
mini-environment filters to further reduce the likelihood that particles are delivered
to the workpiece via airflow.
At the perimeter of the chamber
51, used processing fluid moves out of
the processing chamber
51 through the outlets
30, due to the centrifugal
force. The fluid then flows along the drain path that is aligned with the processing
chamber outlets
30, and continues out of the processor
16 through
the corresponding drain tube. The spent fluid may be delivered to a recycling system
for reuse, or to a disposal area for proper disposal. The drain tubes
80a,
82a,
84a are preferably flexible and are mounted to
move up and down with the drain assembly
70.
When the step of processing with the first processing fluid is completed, a
purge gas, such as N
2 gas, is preferably sprayed from the nozzles
24
and/or
42 toward the outlets
30 to help remove any remaining processing
fluid from the chamber. Depending on whether a second processing fluid or a DI
rinse water is to be used next, the drain assembly
70 is raised further
by the lift mechanism
72 to align the appropriate drain path
82 or
84 with the outlets
30.
For example, if a rinsing step performed with DI rinse water is to be performed
next, the elevator
72 raises the drain assembly
70 until drain path
84, or whichever drain path has been designated for DI water draining, is
aligned with the outlets
30 in the processing chamber. DI rinse water is
then sprayed onto the workpiece surfaces and moves across the workpiece surfaces
to the exterior perimeter of the workpiece
24 via centrifugal force. The
DI rinse water flows through the outlets
30 into the drain path
84.
The DI rinse water flows along the drain path
84 out through the drain tube
84a for removal from the workpiece processor
16. As separate
drain paths are used for the first processing fluid and the DI rinse water, these
liquids are not mixed when they exit the processing chamber
51, and cross-contamination
therefore does not occur.
Similar steps may be performed for one or more additional processing fluids.
A rinsing step may be performed after each processing step, or may be performed
after all processing steps are completed. A drying step performed with isopropyl
alcohol (IPA) vapor or another drying fluid may be performed after the final processing
or
