U.S. patent application number 14/682661 was filed with the patent office on 2015-10-15 for substrate processing apparatus.
The applicant listed for this patent is Ebara Corporation. Invention is credited to Masafumi INOUE, Mitsunori SUGIYAMA.
Application Number | 20150290766 14/682661 |
Document ID | / |
Family ID | 54264319 |
Filed Date | 2015-10-15 |
United States Patent
Application |
20150290766 |
Kind Code |
A1 |
SUGIYAMA; Mitsunori ; et
al. |
October 15, 2015 |
SUBSTRATE PROCESSING APPARATUS
Abstract
The CMP apparatus is provided with a polishing unit 3; a
cleaning unit 4; a load/unload unit for transferring substrates to
the polishing unit 3 and receiving substrates from the cleaning
unit 4; a wafer transporting unit; and a control section 5 for
controlling the timing of loading wafers into the CMP apparatus.
The control section 5 creates a time table correlating treatment
ending times or scheduled treatment ending times in polishing
sections, cleaning sections and transporting sections for each
plurality of wafers to be loaded into the CMP apparatus and
controls the timing of loading the plurality of wafers into the CMP
apparatus on the basis of the time table, so that a standby state
does not occur in a period from when the wafers are loaded into the
CMP apparatus to when cleaning treatment is completed.
Inventors: |
SUGIYAMA; Mitsunori; (Tokyo,
JP) ; INOUE; Masafumi; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ebara Corporation |
Tokyo |
|
JP |
|
|
Family ID: |
54264319 |
Appl. No.: |
14/682661 |
Filed: |
April 9, 2015 |
Current U.S.
Class: |
451/444 |
Current CPC
Class: |
B24B 53/007
20130101 |
International
Class: |
B24B 53/007 20060101
B24B053/007 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 10, 2014 |
JP |
081012/2014 |
Claims
1. A substrate processing apparatus comprising: a polishing unit
including at least one polishing section configured to polish a
substrate; a cleaning unit including at least one cleaning section
configured to clean a substrate polished by the polishing unit; a
load/unload unit configured to transfer a substrate to the
polishing unit and receive a substrate from the cleaning unit; and
a transporting unit including at least one transporting section
configured to transport the substrate, the substrate processing
apparatus being provided with a control section configured to
control the timing of loading the substrate into the substrate
processing apparatus, wherein the control section creates a time
table correlating treatment ending times or scheduled treatment
ending times in the polishing section, the cleaning section and the
transporting section for each plurality of substrates to be loaded
into the substrate processing apparatus and controls the timing of
loading the plurality of substrates into the substrate processing
apparatus on the basis of the time table, so that a standby state
does not occur in a period from when the substrate is loaded into
the substrate processing apparatus to when cleaning treatment is
completed.
2. The substrate processing apparatus according to claim 1, wherein
the control section creates the time table on the basis of
historical records of time taken in treatment in at least one of
the polishing section and the cleaning section and time taken in
transportation from the polishing unit to the cleaning unit in the
transporting section.
3. The substrate processing apparatus according to claim 1, wherein
the control section calculates the provisional times of arrival of
a substrate to be newly loaded at the polishing section, the
cleaning section and the transporting section when creating the
time table for the substrate to be newly loaded into the substrate
processing apparatus, compares the provisional arrival times and
the treatment ending times or the scheduled treatment ending times
of a substrate precedently loaded into the substrate processing
apparatus in the polishing section, the cleaning section and the
transporting section, adds a difference between the earlier
provisional arrival times and the treatment ending times or the
scheduled treatment ending times to the provisional times of
arrival at the polishing section, the cleaning section and the
transporting section, if any provisional arrival time earlier than
the treatment ending times or the scheduled treatment ending times
exists in the same or a conflicting treatment section, to create
actual arrival times, and thus creates the time table on the basis
of the actual arrival times.
4. The substrate processing apparatus according to claim 3, wherein
the control section adds the largest of differences among the
earlier provisional arrival times and the treatment ending times or
the scheduled treatment ending times to the provisional times of
arrival at the polishing section, the cleaning section and the
transporting section, if a plurality of the earlier provisional
arrival times exist, to create actual arrival times, and thus
creates the time table on the basis of the actual arrival
times.
5. The substrate processing apparatus according to claim 3, wherein
the control section creates the time table on the basis of the
provisional arrival times if any provisional arrival time earlier
than the treatment ending times or the scheduled treatment ending
times does not exist in the same or the conflicting treatment
section.
6. The substrate processing apparatus according to claim 2, wherein
the control section calculates the provisional times of arrival of
a substrate to be newly loaded at the polishing section, the
cleaning section and the transporting section when creating the
time table for the substrate to be newly loaded into the substrate
processing apparatus, compares the provisional arrival times and
the treatment ending times or the scheduled treatment ending times
of a substrate precedently loaded into the substrate processing
apparatus in the polishing section, the cleaning section and the
transporting section, adds a difference between the earlier
provisional arrival times and the treatment ending times or the
scheduled treatment ending times to the provisional times of
arrival at the polishing section, the cleaning section and the
transporting section, if any provisional arrival time earlier than
the treatment ending times or the scheduled treatment ending times
exists in the same or a conflicting treatment section, to create
actual arrival times, and thus creates the time table on the basis
of the actual arrival times.
7. The substrate processing apparatus according to claim 4, wherein
the control section creates the time table on the basis of the
provisional arrival times if any provisional arrival time earlier
than the treatment ending times or the scheduled treatment ending
times does not exist in the same or the conflicting treatment
section.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is based upon and claims the benefit of
priority of the prior Japanese Patent Application No. 2014-081012,
filed on Apr. 10, 2014, the entire contents of which are
incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention relates to a substrate processing
apparatus.
BACKGROUND ART
[0003] In recent years, substrate processing apparatuses have been
used to perform various treatments on substrates such as
semiconductor wafers. Examples of the substrate processing
apparatus include a CMP (Chemical Mechanical Polishing) apparatus
for performing polishing treatment on substrates.
[0004] The CMP apparatus is provided with, for example, a polishing
unit for performing polishing treatment on substrates, a cleaning
unit for performing cleaning and drying treatments on substrates,
and a load/unload unit for transferring substrates to the polishing
unit and receiving substrates cleaning and drying-treated by the
cleaning unit. The CMP apparatus is also provided with a
transporting unit for transporting substrates within the polishing
unit, the cleaning unit and the load/unload unit. The CMP apparatus
sequentially performs various treatments, including polishing,
cleaning and drying, while transporting substrates with the
transporting unit.
[0005] Incidentally, a standby state of substrates may occur due
to, for example, a wait for the treatment of preceding substrates
or a wait for the unoccupied state of a treatment section shared by
substrates transported through different routes, in a case where a
plurality of substrates are continuously transported in the CMP
apparatus. For example, if the standby state of substrates occurs
due to temporal change (such as corrosion) or disturbance (such as
dust) during a period from when polishing treatment is started to
when cleaning treatment is finished, the condition of substrates
may become unstable. In a case, in particular, where copper (Cu) is
contained in a portion of a substrate to be polished, a greater
effect of corrosion results if a prolonged standby time is taken
before the start of cleaning after polishing is completed.
[0006] In this regard, the related art proposes reducing the
waiting time of substrates to be transported from the polishing
unit to the cleaning unit by predicting the starting time of
cleaning in the cleaning unit.
CITATION LIST
Patent Literature
[0007] Patent Literature 1: Japanese Patent No. 5023146
[0008] In the substrate processing apparatus high in the degree of
freedom of cleaning treatment and transportation routing in the
cleaning unit, however, the related art does not take into
consideration the reduction of the standby state of substrates in a
period from when the substrates are loaded into the CMP apparatus
to when cleaning treatment is completed.
[0009] That is, the related art assumes that the substrate
processing apparatus successively cleans substrates
polishing-treated by the polishing unit using a plurality of
cleaning sections of the cleaning unit, and then dries and returns
the substrates to the load/unload unit. Accordingly, in the related
art, a standby state of substrates may occur within the cleaning
unit if substrate transportation routes within the cleaning unit
are complicated by including, for example, a plurality of cleaning
sections capable of concurrently performing cleaning treatment in
the cleaning unit. Once a standby state of substrates occurs within
the cleaning unit, a standby state may also occur in subsequent
substrates scheduled to pass through a location where the
abovementioned substrates are situated.
[0010] Hence, it is an object of the present invention to reduce
the standby state of substrates in a period from when the
substrates are loaded into a CMP apparatus to when cleaning
treatment is completed in a substrate processing apparatus high in
the degree of freedom of cleaning treatment and transportation
routing in a cleaning unit.
SUMMARY OF INVENTION
[0011] In one embodiment of a substrate processing apparatus of the
present invention which has been accomplished in view of the
above-described problem, the substrate processing apparatus is
provided with a polishing unit including at least one polishing
section configured to polish a substrate; a cleaning unit including
at least one cleaning section configured to clean a substrate
polished by the polishing unit; a load/unload unit configured to
transfer a substrate to the polishing unit and receive a substrate
from the cleaning unit; and a transporting unit including at least
one transporting section configured to transport the substrate, the
substrate processing apparatus being provided with a control
section configured to control the timing of loading the substrate
into the substrate processing apparatus, wherein the control
section creates a time table correlating treatment ending times or
scheduled treatment ending times in the polishing section, the
cleaning section and the transporting section for each plurality of
substrates to be loaded into the substrate processing apparatus and
controls the timing of loading the plurality of substrates into the
substrate processing apparatus on the basis of the time table, so
that a standby state does not occur in a period from when the
substrate is loaded into the substrate processing apparatus to when
cleaning treatment is completed.
[0012] In another embodiment of the substrate processing apparatus,
the control section can create the time table on the basis of
historical records of time taken in treatment in at least one of
the polishing section and the cleaning section and time taken in
transportation from the polishing unit to the cleaning unit in the
transporting section.
[0013] In yet another embodiment of the substrate processing
apparatus, the control section calculates the provisional times of
arrival of a substrate to be newly loaded at the polishing section,
the cleaning section and the transporting section when creating the
time table for the substrate to be newly loaded into the substrate
processing apparatus, compares the provisional arrival times and
the treatment ending times or the scheduled treatment ending times
of a substrate precedently loaded into the substrate processing
apparatus in the polishing section, the cleaning section and the
transporting section, adds a difference between the earlier
provisional arrival times and the treatment ending times or the
scheduled treatment ending times to the provisional times of
arrival at the polishing section, the cleaning section and the
transporting section, if any provisional arrival time earlier than
the treatment ending times or the scheduled treatment ending times
exists in the same or a conflicting treatment section, to create
actual arrival times, and can thus create the time table on the
basis of the actual arrival times.
[0014] In still another embodiment of the substrate processing
apparatus, the control section adds the largest of differences
among the earlier provisional arrival times and the treatment
ending times or the scheduled treatment ending times to the
provisional times of arrival at the polishing section, the cleaning
section and the transporting section, if a plurality of the earlier
provisional arrival times exist, to create actual arrival times,
and can thus create the time table on the basis of the actual
arrival times.
[0015] In still another embodiment of the substrate processing
apparatus, the control section can create the time table on the
basis of the provisional arrival times if any provisional arrival
time earlier than the treatment ending times or the scheduled
treatment ending times does not exist in the same or the
conflicting treatment section.
[0016] According to the present invention described above, it is
possible to reduce the standby state of substrates in a period from
when the substrates are loaded into the CMP apparatus to when
cleaning treatment is completed in the substrate processing
apparatus high in the degree of freedom of cleaning treatment and
transportation routing in the cleaning unit.
BRIEF DESCRIPTION OF DRAWINGS
[0017] FIG. 1 is a plan view illustrating the overall configuration
of a substrate processing apparatus according to one embodiment of
the present invention;
[0018] FIG. 2 is a schematic view illustrating one example of
routes of wafer transportation in a period from when a wafer is
loaded into a CMP apparatus to when cleaning treatment is
completed;
[0019] FIG. 3 is a schematic view illustrating another example of
routes of wafer transportation in a period from when a wafer is
loaded into a CMP apparatus to when cleaning treatment is
completed;
[0020] FIG. 4 is a flowchart showing the operation of a CMP
apparatus of the present embodiment;
[0021] FIG. 5 is a schematic view used to describe a process of
creating time tables;
[0022] FIG. 6 is a tabular view illustrating one example of a time
table; and
[0023] FIG. 7 is a schematic view illustrating one example of a
graphed time table.
DESCRIPTION OF EMBODIMENTS
[0024] Hereinafter, a substrate processing apparatus according to
one embodiment of the present invention will be described based on
the accompanying drawings. In the following, a CMP apparatus will
be described as one example of the substrate processing apparatus,
though the substrate processing apparatus is not limited this CMP
apparatus. Also in the following, a substrate processing apparatus
provided with a load/unload unit 2, a polishing unit 3 and a
cleaning unit 4 will be described, though the substrate processing
apparatus is not limited to this apparatus.
[0025] The configuration of the CMP apparatus will be described
first, and then a description will be made of the reduction of a
standby state of substrates.
[0026] <Substrate Processing Apparatus>
[0027] FIG. 1 is a plan view illustrating the overall configuration
of the substrate processing apparatus according to one embodiment
of the present invention. As illustrated in FIG. 1, this CMP
apparatus is provided with a substantially rectangular housing 1.
The interior of the housing 1 is partitioned into a load/unload
unit 2, a polishing unit 3 and a cleaning unit 4 by bulkheads 1a
and 1b. The load/unload unit 2, the polishing unit 3 and the
cleaning unit 4 are assembled independent of one another and
evacuated separately. The cleaning unit 4 includes a control
section 5 used to control substrate treatment actions. While
configured to control the overall operation of the CMP apparatus,
the control section 5 controls the timing of loading substrates
into the polishing unit 3 in particular in the present embodiment.
Details on this operation will be described later.
[0028] <Load/Unload Unit>
[0029] The load/unload unit 2 is provided with two or more (four in
the present embodiment) front load sections 20 on which wafer
cassettes for containing a multitude of wafers (substrates) are
mounted. These front load sections 20 are disposed adjacently to
the housing 1 and laid out along the width direction (direction
perpendicular to the longitudinal direction) of the substrate
processing apparatus. An open cassette, a SMIF (Standard
Manufacturing Interface) pod, or a carrier, such as a FOUP
(Front-Opening Unified Pod), used to store wafers can be mounted on
each front load section 20. Here, the SMIF and FOUP are airtight
containers capable of maintaining an environment independent of an
external space by being covered with bulkheads with wafer cassettes
housed in the containers.
[0030] The load/unload unit 2 is also provided with an ITM (In-line
Thickness Monitor) 24 serving as a measuring section for measuring
a film thickness on a wafer surface. A transport robot (a loader
and a transport mechanism) 22 movable along the array direction of
the front load section 20 is mounted on the load/unload unit 2. The
transport robot 22 can gain access to wafer cassettes mounted on
the front load sections 20. Each transport robot 22 is provided
with two hands on the upper and lower sides thereof. The upper hand
is used when a treated wafer is returned to a wafer cassette. The
lower hand is used when a wafer before treatment is taken out of a
wafer cassette. In addition, the lower hand of each transport robot
22 is configured to rotate around the axis thereof to be able to
turn over a wafer.
[0031] The load/unload unit 2 is an area that needs to be
maintained in the cleanest state. Accordingly, the internal
pressure of the load/unload unit 2 is constantly kept higher than
the external pressure of the CMP apparatus and the internal
pressures of the polishing unit 3 and the cleaning unit 4. The
polishing unit 3 uses slurry as a polishing liquid and is,
therefore, the most unclean area. Accordingly, a negative pressure
is formed inside the polishing unit 3 and is kept lower than the
internal pressure of the cleaning unit 4. A filter fan unit (not
illustrated) including a clean air filter, such as a HEPA filter,
an ULPA filter or a chemical filter, is disposed in the load/unload
unit 2. Clean air from which particles, toxic vapor and toxic gas
have been removed blows out constantly from this filter fan
unit.
[0032] <Polishing Unit>
[0033] The polishing unit 3 is an area where a wafer is polished
(planarized). The polishing unit 3 is provided with a first
polishing section 3A, a second polishing section 3B, a third
polishing section 3C and a fourth polishing section 3D. These first
polishing section 3A, second polishing section 3B, third polishing
section 3C and fourth polishing section 3D are laid out along the
longitudinal direction of the substrate processing apparatus, as
illustrated in FIG. 1.
[0034] The first polishing section 3A is provided with a polishing
table fitted with an abrasive pad. The first polishing section 3A
is also provided with a top ring for holding and polishing a wafer,
while pressing the wafer against the abrasive pad on the polishing
table. The first polishing section 3A is further provided with a
polishing liquid supply nozzle for supplying a polishing liquid and
a dressing liquid (for example, pure water) to the abrasive pad.
The first polishing section 3A is further provided with a dresser
for dressing the polishing surface of the abrasive pad. The first
polishing section 3A is further provided with an atomizer for
nebulizing and spraying a fluid mixture of a liquid (for example,
pure water) and a gas (for example, nitrogen gas) or a liquid (for
example, pure water) onto the polishing surface. The second
polishing section 3B, the third polishing section 3C and the fourth
polishing section 3D have the same configuration as the first
polishing section 3A.
[0035] <Transporting Unit>
[0036] Next, a description will be made of a transport mechanism
(transporting unit) for transporting wafers. As illustrated in FIG.
1, a first linear transporter 6 is disposed adjacently to the first
polishing section 3A and the second polishing section 3B. This
first linear transporter 6 is a mechanism for transporting wafers
among four transport positions (defined as a first transport
position LTP1, a second transport position LTP2, a third transport
position LTP3 and a fourth transport position LTP4 in order from
the load/unload unit side) along the direction in which the
polishing sections 3A and 3B are laid out.
[0037] Likewise, a second linear transporter 7 is disposed
adjacently to the third polishing section 3C and the fourth
polishing section 3D. The second linear transporter 7 is a
mechanism for transporting wafers among three transport positions
(defined as a fifth transport position LTP5, a sixth transport
position LTP6 and a seventh transport position LTP7 in order from
the load/unload unit side) along the direction in which the
polishing sections 3C and 3D are laid out.
[0038] Wafers are transported to the polishing sections 3A and 3B
by the first linear transporter 6. The top ring of the first
polishing section 3A moves between a polishing position and the
second transport position LTP2 due to the swinging action of a top
ring head. Accordingly, a wafer is transferred to and from the top
ring at the second transport position LTP2. Likewise, the top ring
of the second polishing section 3B moves between a polishing
position and the third transport position LTP3. Thus, a wafer is
transferred to and from the top ring at the third transport
position LTP3. The top ring of the third polishing section 3C moves
between a polishing position and the sixth transport position LTP6.
Thus, a wafer is transferred to and from the top ring at the sixth
transport position LTP6. The top ring of the fourth polishing
section 3D moves between a polishing position and the seventh
transport position LTP7. Thus, a wafer is transferred to and from
the top ring at the seventh transport position LTP7.
[0039] A lifter 11 for receiving a wafer from a transport robot 22
is disposed in the first transport position LTP1. The wafer is
transferred from the transport robot 22 to the first linear
transporter 6 by way of this lifter 11. A shutter (not illustrated)
is disposed in the bulkhead 1a, so as to locate between the lifter
11 and the transport robot 22. The shutter is opened at the time of
transporting the wafer, so that the wafer is transferred from the
transport robot 22 to the lifter 11. In addition, a swing
transporter (STP) 12 is disposed among the first linear transporter
6, the second linear transporter 7 and the cleaning unit 4. This
swing transporter 12 includes a hand movable between the fourth
transport position LTP4 and the fifth transport position LTP5.
Wafer transfer from the first linear transporter 6 to the second
linear transporter 7 is made by the swing transporter 12. A wafer
is transported to the third polishing section 3C and/or the fourth
polishing section 3D by the second linear transporter 7. A wafer
polished by the polishing unit 3 is transported to the cleaning
unit 4 through the swing transporter 12. A temporary pedestal (WS1)
180 for wafers is provided in the transporting unit.
[0040] <Cleaning Unit>
[0041] The cleaning unit 4 is partitioned into a first cleaning
chamber 190, a first transport chamber 191, a second cleaning
chamber 192, a second transport chamber 193, and a third cleaning
chamber 194. Two cleaning sections CL1A and CL1B and a temporary
pedestal WS2 for wafers are disposed in the first cleaning chamber
190. Two cleaning sections CL2A and CL2B and a temporary pedestal
WS3 for wafers are disposed in the second cleaning chamber 192. Two
cleaning sections CL3A and CL3B for cleaning substrates are
disposed in the third cleaning chamber 194. The cleaning sections
CL3A and CL3B are isolated from each other. The cleaning sections
CL1A, CL11B, CL2A, CL2B, CL3A and CL3B are cleaning machines used
to clean wafers with a cleaning liquid.
[0042] Transfer robots (transport mechanisms) RB1U and RB1L are
disposed in the first transport chamber 191, and a transfer robot
RB2 is disposed in the second transport chamber 193. The transfer
robots RB1U and RB1L are operable to transport wafers among the
temporary pedestal 180, the cleaning sections CL1A and CL1B, the
temporary pedestal WS2, and the cleaning sections CL2A and CL2B.
The transfer robot RB2 is operable to transport wafers among the
cleaning sections CL2A and CL2B, the temporary pedestal WS3, and
the cleaning sections CL3A and CL3B. The transport robot RB2
transports a cleaned wafer only, and therefore, includes only one
hand. The transport robot 22 takes out a wafer from the cleaning
sections CL3A and CL3B and returns the wafer to a wafer
cassette.
[0043] <Reduction of Standby State of Substrates>
[0044] Next, a description will be made of the reduction of a
standby state of substrates in a period from when polishing
treatment is started to when cleaning treatment is completed.
[0045] First, a description will be made of causes for the
occurrence of a standby state of substrates. FIGS. 2 and 3 are
schematic views illustrating one example of routes of wafer
transportation in a period from when wafers are loaded into the CMP
apparatus to when cleaning treatment is completed. In FIGS. 2 and
3, the description is simplified with regard to the transporting
unit for transporting wafers among respective treatment
sections.
[0046] As illustrated in FIGS. 2 and 3, the present embodiment
includes two systems each of polishing treatment and cleaning
treatment. Accordingly, the present embodiment is high in the
degree of freedom of wafer transportation routing. In addition,
such a recipe in which cleaning treatment is performed without
performing polishing treatment is also available, as illustrated in
FIGS. 2 and 3. Yet additionally, complex wafer transportation
routing is possible in which, for example, a wafer is
back-transferred once after cleaning treatment is completed in the
cleaning section CL2A, and then transported to the cleaning section
CL2B of another system, as illustrated in FIG. 3.
[0047] As described above, wafer transportation routes within the
cleaning unit become complicated if the cleaning unit 4 includes a
plurality of cleaning sections capable of concurrently performing
cleaning treatment. As a result, a standby state of wafers may
occur in the cleaning unit. Once a standby state of substrates
occurs within the cleaning unit, a standby state may also occur in
subsequent substrates scheduled to pass through a location where
the abovementioned substrates are situated.
[0048] In contrast, in the present embodiment, the control section
5 creates a time table, so that a standby state does not occur in a
period from when wafers are loaded into the CMP apparatus to when
cleaning treatment is completed. The time table is a table
correlating treatment ending times or the scheduled treatment
ending times in the polishing section, the cleaning section and the
transporting section for each plurality of wafers to be loaded into
the CMP apparatus. The control section 5 controls the timing of
loading a plurality of wafers into the CMP apparatus on the basis
of the time table.
[0049] Details on this operation will be described along with the
overall operation of the CMP apparatus. FIG. 4 is a flowchart
illustrating the operation of the CMP apparatus of the present
embodiment. As illustrated in FIG. 4, the control section 5 first
predicts transportation routes for all of wafers to be loaded into
the CMP apparatus on the basis of a recipe (step S101).
[0050] Subsequently, the control section 5 predicts operating times
for all of wafers to be loaded into the CMP apparatus (step S102).
Specifically, the control section 5 predicts an operating time for
each wafer on the basis of predicted times set in the recipe or
historical record values. This predicted operating time is used
when creating the time table. That is, the control section 5
creates the time table on the basis of historical records of time
taken in treatment in at least one of the polishing section and the
cleaning section and time taken in transportation from the
polishing unit 3 to the cleaning unit 4 in the transporting
section.
[0051] Subsequently, the control section 5 calculates the times of
arrival of each wafer at respective treatment sections (polishing
sections, transporting sections, and cleaning sections) on the
basis of the operating times of each wafer predicted in step S102
(step S103). Then, the control section 5 calculates the standby
time of each wafer in each treatment section (step S104).
[0052] This operation will be described using drawings. FIG. 5 is a
schematic view used to describe a process of creating time tables.
FIG. 5 illustrates a process of creating a time table for a wafer 4
to be newly loaded into the CMP apparatus, where time tables have
already been created for wafers 1 to 3.
[0053] As illustrated in FIG. 5, treatment ending times or
scheduled treatment ending times in the polishing section (Poli,
A), the cleaning sections (CL1A and CL2A), and the transporting
sections (LTP3, WS1, RB1L and RB1U) are correlated in a time table
210 for each of the wafers 1 to 3. On the other hand, the control
section 5 calculates the provisional times of the arrival of the
newly-loaded wafer 4 at the polishing section, the cleaning section
and the transporting section when creating the time table for the
wafer 4 to be newly loaded into the CMP apparatus. The scheduled
times of arrival of the wafer 4 at the polishing section (Poli, A),
the cleaning sections (CL1A and CL2A) and the transporting sections
(LTP3, WS1, RB1L and RB1U) are correlated with a provisional
arrival time table 220.
[0054] The control section 5 compares the provisional arrival times
(provisional arrival time table 220) and the treatment ending times
or the scheduled treatment ending times (time table 210) of wafers
precedently loaded into the CMP apparatus in the polishing
sections, the cleaning sections and the transporting sections. In
this example, the control section 5 compares, for example, the
scheduled treatment ending time (0:04:35) of the wafer 3 in the
RB1U and the scheduled arrival time (0:04:10) of the wafer in the
WS1 which is a treatment section conflicting in treatment with the
RB1U. The result is that the scheduled arrival time in the WS1 is
25 seconds earlier. In other words, the wafer 4 stands by in the
WS1 for 25 seconds if the wafer 4 is loaded into the CMP apparatus
according to the provisional arrival time table 220. Note that the
conflicting treatment section refers to a treatment section in such
a relationship as the relationship between, for example, the WS1
and the RB1U in which in order for one treatment section (WS1) to
operate (transfer a wafer for transportation), the other treatment
section (RB1U) has to operate (receive the wafer from the WS1).
[0055] As illustrated in FIG. 4, the control section 5 determines
whether or not there are any standby times (step S105). If there
are standby times (Yes in step S105), the control section 5
searches for a treatment section having the longest waiting time
(step S106).
[0056] For example, a 25-second standby time arises between
treatment sections associated with each other, such as the RB1U for
the wafer 3 and the WS1 for the wafer 4, as described above in the
example of FIG. 5. In addition, the control section 5 compares the
scheduled treatment time (0:04:30) of the wafer 3 in the CL1A and
the arrival time (0:04:15) of the wafer 4 in the CL1A. The result
is that the scheduled arrival time in the CL1A is 15 seconds
earlier, and therefore, a 15-second standby time arises.
[0057] In this case, the control section 5 recognizes that the
longest waiting time is 25 seconds and a treatment section having
the longest waiting time is the WS1 for the wafer 4. In other
words, if there are a plurality of earlier provisional arrival
times (for example, 15 and 25 seconds), the control section 5 adds
the largest (25 seconds) of differences among the earlier
provisional arrival times and the treatment ending times or the
scheduled treatment ending times to the provisional times of
arrival at the polishing section, the cleaning section and
transporting section to create actual arrival times.
[0058] Subsequently, as illustrated in FIG. 4, the control section
5 adds the longest waiting time to the provisional arrival time
table 220 to create an actual arrival time table 230 (step S107).
That is, the control section 5 adds the longest waiting time (25
seconds) for each treatment section listed on the provisional
arrival time table 220, as illustrated in FIG. 5. For example, the
time of arrival of the wafer 4 at the LTP3, which is 0:04:00 on the
provisional arrival time table 220, changes to 0:04:25 on the
actual arrival time table 230. Likewise, the time of arrival of the
wafer 4 at the WS1, which is 0:04:10 on the provisional arrival
time table 220, changes to 0:04:35 on the actual arrival time table
230.
[0059] In this way, the control section 5 adds a difference between
the earlier provisional arrival times and the treatment ending
times or the scheduled treatment ending times to the provisional
times of arrival at the polishing sections, the cleaning sections
and the transporting sections, if any provisional arrival time
earlier than the treatment ending times or the scheduled treatment
ending times exists in the same or a conflicting treatment section,
to create actual arrival times.
[0060] Subsequently, as illustrated in FIG. 4, the control section
5 creates a time table on the basis of the actual arrival times
(actual arrival time table 230) created in step S107 (step S108).
That is, the actual arrival time table 230 correlates the times of
arrival of the wafer 4 at respective treatment sections. Hence, the
control section 5 adds treating times in the respective treatment
sections to the actual arrival time table 230 to create a time
table correlating treatment ending times or scheduled treatment
ending times in the respective treatment sections.
[0061] On the other hand, if the control section 5 determines, in
step S105, that there is no standby time (No in step S105), the
control section 5 creates a time table on the basis of the
provisional arrival time table 220 without creating the actual
arrival time table 230 (step S108). That is, the control section 5
creates a time table on the basis of the provisional arrival times
if there is no provisional arrival time earlier than the treatment
ending times or the scheduled treatment ending times in the same or
a conflicting treatment section.
[0062] FIG. 6 is a tabular view illustrating one example of a time
table 240. As illustrated in FIG. 6, the time table 240 is a table
in which the starting time of a series of treatments (Start), the
current positions of wafers (Pos), treatment ending times or
scheduled treatment ending times in respective treatment sections
are correlated for each plurality of wafers to be loaded into the
CMP apparatus. The time table 240 is used to prevent any standby
states from occurring in a period from when wafers are loaded into
the CMP apparatus to when cleaning treatment is completed. The time
table 240 is created by performing a series of operations shown in
FIG. 4. The control section 5 controls the timing of loading a
plurality of wafer into the CMP apparatus on the basis of the time
table 240.
[0063] As described above, according to the present embodiment, the
times of transportation to all of treatment sections present on
transportation routes are calculated for all of wafers to be loaded
into the CMP apparatus to create a time table. Consequently, the
control section 5 of the present embodiment controls the timing of
starting transportation and transportation routes, so that a wait
for use of each treatment section shared among respective wafers
does not occur and that all processes from the start of polishing
to the end of cleaning are carried out in the shortest period of
time without involving any standby states. The waiting time of
wafers within the CMP apparatus is thus reduced. As a result, the
present embodiment can prevent wafers from becoming unstable due to
temporal change (such as corrosion) or disturbance (such as dust).
In a case, in particular, where copper (Cu) is contained in a
portion of a wafer to be polished, a greater effect of corrosion
results if a prolonged standby time is taken before the start of
cleaning after polishing is completed. It is possible, however, to
prevent copper from corrosion by reducing the standby time.
[0064] In addition, if, for example, there are any treatment
sections incapable of treating wafers due to the maintenance or the
like of some of the treatment sections of the CMP apparatus, the
CMP apparatus (control section 5) of the present embodiment can
create routes that detour around the treatment sections under
maintenance or the like.
[0065] Yet additionally, the CMP apparatus of the present
embodiment can, as appropriate, update the time table 240 created
once. For example, the control section 5 can calculate a difference
between the actual time of arrival of a wafer at each treatment
section and the predicted arrival time of the wafer to update the
time table 240 for subsequent wafers that pass through the
treatment sections (wafers to be affected by delay). The control
section 5 can also feed delay information back to wafers already
loaded into the CMP apparatus. Note that the control section 5 can
be configured not to feed back delay information if a difference
between the actual arrival time and the predicted arrival time of a
wafer is smaller than a threshold (for example, 0.5 seconds), since
the time difference can be regarded as an error.
[0066] Still additionally, if the transportation of wafers is
temporarily suspended due to the malfunction or the transport stop
function of the CMP apparatus, the CMP apparatus (control section
5) of the present embodiment recreates the time table 240 at the
restart of transportation and, therefore, can continue controlled
transportation. When recreating the time table 240, the control
section 5 begins the recreation from the downstream side of a
transportation route of wafers. If a wafer loaded into the CMP
apparatus is removed therefrom due to, for example, the anomaly of
the wafer, the control section 5 can delete the wafer from the time
table 240 to exclude the wafer from the objects of control and
recreate the time table 240.
[0067] Still additionally, if wafers share a treatment section, the
CMP apparatus (control section 5) of the present embodiment makes
calculations and performs control, so that the next wafer is
treated after a preceding wafer. On the other hand, if interruption
is possible without changing the time table 240, the control
section 5 can create a time table 240 to interrupt with, so that
subsequent wafers can be treated earlier than the preceding
wafer.
[0068] If, for example, a transportation route of wafers is greatly
changed due to the maintenance or the like of treatment sections
after the time table 240 is created once, the CMP apparatus
(control section 5) of the present embodiment takes a prolonged
period of time in recreating the time table 240. Hence, in such a
case, the control section 5 can stop loading new wafers until
wafers within the CMP apparatus are carried out of the CMP
apparatus, without recreating the time table 240. In addition, the
control section 5 can disable the function of creating or
recreating the time table 240 if a prolonged period time is
required to create or recreate the time table 240.
[0069] Still additionally, the CMP apparatus (control section 5) of
the present embodiment can visualize the state of transportation of
a plurality of wafers, so that an operator or the like can monitor
the state of transportation of the plurality of wafers. For
example, the control section 5 can display the time table 240 shown
in FIG. 6 on an output interface (monitor, or the like) of the CMP
apparatus. In addition, the control section 5 can graph the time
table 240 and display the graph in real time on the output
interface.
[0070] FIG. 7 is a schematic view illustrating one example the time
table 240 made into a graph. In FIG. 7, the axis of abscissas (t)
represents a time course. As illustrated in FIG. 7, the control
section 5 can lay out and display wafer-treating sections in
chronological order for each plurality of wafers. In addition, the
control section 5 can apply a different color or pattern for each
treatment section. Consequently, an operator or the like can easily
confirm that the same or a conflicting treatment section is not
used at the same point in time. Yet additionally, if a standby
state occurs in a wafer for some reason, the control section 5 can
display the remaining time of the standby state through an
indicator or the like.
REFERENCE SIGNS LIST
[0071] 2: Load/unload unit
[0072] 3: Polishing unit
[0073] 3A to 3D: Polishing section
[0074] 4: Cleaning unit
[0075] 5: Control section
[0076] 210, 240: Time table
[0077] 220: Provisional arrival time table
[0078] 230: Actual arrival time table
[0079] CL1A, CL1B, CL2A, CL2B, CL3A, CL3B: Cleaning section
* * * * *