U.S. patent application number 14/663548 was filed with the patent office on 2015-07-09 for vacuum processing system and vacuum processing method of semiconductor processing substrate.
This patent application is currently assigned to HITACHI HIGH-TECHNOLOGIES CORPORATION. The applicant listed for this patent is HITACHI HIGH-TECHNOLOGIES CORPORATION. Invention is credited to Takafumi Chida, Hideaki Kondo, Teruo Nakata, Keita Nogi, Atsushi Shimoda, Susumu Tauchi.
Application Number | 20150194327 14/663548 |
Document ID | / |
Family ID | 43974280 |
Filed Date | 2015-07-09 |
United States Patent
Application |
20150194327 |
Kind Code |
A1 |
Tauchi; Susumu ; et
al. |
July 9, 2015 |
VACUUM PROCESSING SYSTEM AND VACUUM PROCESSING METHOD OF
SEMICONDUCTOR PROCESSING SUBSTRATE
Abstract
A vacuum processing system of a semiconductor processing
substrate and a vacuum processing method using the same comprises
an atmospheric transfer chamber having a plurality of cassette
stands for transferring a wafer, a lock chamber for storing the
wafer transferred from the atmospheric transfer chamber, a first
vacuum transfer chamber to which the wafer from the lock chamber is
transferred, a transfer intermediate chamber connected to the first
vacuum transfer chamber, a second vacuum transfer chamber connected
to the transfer intermediate chamber, at least one vacuum
processing chamber connected to the first vacuum transfer chamber,
and two or more vacuum processing chambers connected to a rear side
of the second vacuum transfer chamber, wherein the number of vacuum
processing chambers connected to the first vacuum transfer chamber
is smaller than the number of vacuum processing chambers connected
to the second vacuum transfer chamber, or the number of use of
vacuum processing chambers connected to the first vacuum transfer
chamber is restricted to one.
Inventors: |
Tauchi; Susumu; (Shunan-shi,
JP) ; Kondo; Hideaki; (Kudamatsu-shi, JP) ;
Nakata; Teruo; (Yokohama-shi, JP) ; Nogi; Keita;
(Tokyo, JP) ; Shimoda; Atsushi; (Hiratsuka-shi,
JP) ; Chida; Takafumi; (Chigasaki-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HITACHI HIGH-TECHNOLOGIES CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
HITACHI HIGH-TECHNOLOGIES
CORPORATION
Tokyo
JP
|
Family ID: |
43974280 |
Appl. No.: |
14/663548 |
Filed: |
March 20, 2015 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12871333 |
Aug 30, 2010 |
9011065 |
|
|
14663548 |
|
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|
Current U.S.
Class: |
414/217 ;
414/805 |
Current CPC
Class: |
H01L 21/67184 20130101;
H01L 21/67745 20130101; Y10S 414/139 20130101; H01L 21/67201
20130101; H01L 21/67196 20130101; H01L 21/67769 20130101 |
International
Class: |
H01L 21/67 20060101
H01L021/67; H01L 21/677 20060101 H01L021/677 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 12, 2009 |
JP |
2009-258491 |
Claims
1. A vacuum processing apparatus which processes semiconductor
wafers, comprising: an atmospheric transfer housing having a
plurality of cassette stands arranged on a front side thereof, the
wafer being stored in a cassette disposed on one of the plurality
of cassette stands and the wafers being transferred in a space
disposed inside the atmospheric transfer housing; a lock chamber
unit arranged on a rear side of the atmospheric transfer housing,
an interior space of the lock chamber unit being configured to
store the plurality of wafers therein; a first vacuum transfer
chamber connected to a rear side of the lock chamber unit, an
inside of the first vacuum transfer chamber being configured to be
evacuated and through which the wafer is transferred; a second
vacuum transfer chamber disposed in a rear side of the first vacuum
transfer chamber, an inside of the second vacuum transfer chamber
being configured to be evacuated and through which the wafer is
transferred; a transfer intermediate unit which is disposed between
the first vacuum transfer chamber and the second vacuum transfer
chamber, an interior space of the transfer intermediate unit being
configured to store the plurality of wafers and to communicate with
the inside of the first vacuum transfer chamber and the second
vacuum transfer chamber; a first transfer robot and a second
transfer robot disposed in the first vacuum transfer and the second
vacuum transfer chamber, respectively, each transfer robot
including a plurality of arms on which the wafer is mounted and
transferred; a first vacuum processing chamber coupled to a lateral
side of the first vacuum transfer chamber for processing the wafer
transferred thereto from the first vacuum transfer chamber; a
second vacuum processing chamber coupled to a lateral side or a
rear side of the second vacuum transfer chamber for processing the
wafer transferred thereto from the second vacuum transfer chamber;
a control unit which controls an operation of the transfer of the
plurality of wafers transferred into the lock chamber unit, the
operation of the transfer of the plurality of wafers being held by
the first and second transfer robot; wherein a time period for
transferring the wafer by the first transfer robot between the lock
chamber unit and the first vacuum processing chamber and a time
period for transferring the wafer by the second transfer robot
between the transfer intermediate unit and the second vacuum
processing chamber is longer than a time period for transferring
the wafer by the first transfer robot between the lock chamber unit
and the transfer intermediate unit; and wherein the control unit is
configured to control the operation transferring sequentially the
plurality of wafers transferred into the lock chamber unit from the
space in the atmospheric transfer housing so that the each of the
plurality of wafers is transferred by the first transfer robot from
the lock chamber unit to the first vacuum processing chamber and is
processed therein and thereafter transferred back to the lock
chamber unit by the first transfer robot, or is transferred by the
first transfer robot from the lock chamber unit to the transfer
intermediate unit and transferred by the second transfer robot from
the transfer intermediate unit to the second vacuum processing
chamber via the second vacuum transfer chamber and is processed
therein and thereafter transferred back to the transfer
intermediate unit by the second transfer robot and transferred back
from the transfer intermediate unit to the lock chamber unit by the
first transfer robot; and the control unit is further configured to
control the operation of the transfer so that a number of the
wafers transferred to the second vacuum processing chamber and
processed therein during a predetermined time is larger than a
number of the wafers transferred to the first vacuum processing
chamber and processed therein during the predetermined time.
2. A vacuum processing apparatus according to claim 1, wherein the
control unit is further configured to control the operation of the
transfer of the plurality of wafers sequentially from the lock
chamber unit to the one of the first or second vacuum processing
chamber and transferred back to the lock chamber unit, so that an
amount of time periods for transferring the wafers between the
transfer intermediate unit and the second vacuum transfer chamber
is larger than an amount of time periods for transferring the
wafers between the lock chamber unit and the first vacuum transfer
chamber.
3. An operating method of a vacuum processing apparatus which
processes semiconductor wafers, the vacuum processing apparatus
comprising: an atmospheric transfer housing having a plurality of
cassette stands arranged on a front side thereof, the wafer being
stored in a cassette disposed on one of the plurality of cassette
stands and the wafers being transferred in a space disposed inside
the atmospheric transfer housing; a lock chamber unit arranged on a
rear side of the atmospheric transfer housing, an interior space of
the lock chamber unit being configured to store the plurality of
wafers therein; a first vacuum transfer chamber connected to a rear
side of the lock chamber unit, an inside of the first vacuum
transfer chamber being configured to be evacuated and through which
the wafer is transferred; a second vacuum transfer chamber disposed
in a rear side of the first vacuum transfer chamber, an inside of
the second vacuum transfer chamber being configured to be evacuated
and through which the wafer is transferred; a transfer intermediate
unit which is disposed between the first vacuum transfer chamber
and the second vacuum transfer chamber, an interior space of the
transfer intermediate unit being configured to store the plurality
of wafers and to communicate with the inside of the first vacuum
transfer chamber and the second vacuum transfer chamber; a first
transfer robot and a second transfer robot disposed in the first
vacuum transfer and the second vacuum transfer chamber,
respectively, each transfer robot including a plurality of arms on
which the wafer is mounted and transferred; a first vacuum
processing chamber coupled to a lateral side of the first vacuum
transfer chamber for processing the wafer transferred thereto from
the first vacuum transfer chamber; a second vacuum processing
chamber coupled to a lateral side or a rear side of the second
vacuum transfer chamber for processing the wafer transferred
thereto from the second vacuum transfer chamber; wherein a time
period for transferring the wafer by the first transfer robot
between the lock chamber unit and the first vacuum processing
chamber and a time period for transferring the wafer by the second
transfer robot between the transfer intermediate unit and the
second vacuum processing chamber is longer than a time period for
transferring the wafer by the first transfer robot between the lock
chamber unit and the transfer intermediate unit; and the operation
method of the vacuum processing apparatus comprises: transferring
the plurality of wafers sequentially which are transferred from the
space in the atmospheric housing into the lock chamber unit so that
the each of the plurality of wafers is transferred by the first
transfer robot from the lock chamber unit to the first vacuum
processing chamber and is processed therein and thereafter
transferred back to the lock chamber unit by the first transfer
robot, or is transferred by the first transfer robot from the lock
chamber unit to the transfer intermediate unit by the first
transfer robot and transferred by the second transfer robot from
the transfer intermediate unit to the second vacuum processing
chamber via the second vacuum transfer chamber and is processed
therein and thereafter transferred back to the transfer
intermediate unit by the second transfer robot and transferred back
from the transfer intermediate unit to the lock chamber unit by the
first transfer robot; and wherein a number of the wafers
transferred to the second vacuum processing chamber and processed
therein during a predetermined time is larger than a number of the
wafers transferred to the first vacuum processing chamber and
processed therein during the predetermined time.
4. An operation method of the vacuum processing apparatus according
to claim 3, wherein an amount of time periods for transferring the
wafers between the transfer intermediate unit and the second vacuum
transfer chamber is larger than an amount of time periods for
transferring the wafers between the lock chamber unit and the first
vacuum transfer chamber.
Description
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/871,333, filed on Aug. 30, 2010, which is
based on and claims priority of Japanese Patent Application No.
2009-258491, filed on Nov. 12, 2009, the entire contents of each of
which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the arrangement of a vacuum
processing system having a transfer mechanism of a semiconductor
processing substrate (including semiconductor wafers and other
substrate-shaped samples, hereinafter simply referred to as a
"wafer") disposed between a vacuum processing chamber and a vacuum
transfer chamber of a semiconductor processing apparatus, and a
vacuum processing method using this system. Especially, the present
invention relates to the arrangement of a vacuum processing system
having a plurality of vacuum processing chambers connected in
series via a transfer mechanism disposed within a plurality of
vacuum transfer chambers, and a vacuum processing method using the
same.
[0004] 2. Description of the Related Art
[0005] In the art related to the above-described type of
apparatuses, especially apparatuses for processing objects within a
decompressed chamber, there are demands for enhancing the
microfabrication and precision of the process, and for enhancing
the processing efficiency of the substrate to be processed. In
response to such demands, there has been developed a multiple
chamber apparatus in which a plurality of vacuum processing
chambers are disposed in a single apparatus, according to which the
production efficiency per footprint within a clean room has been
improved.
[0006] According to such apparatus equipped with a plurality of
vacuum processing chambers and other chambers used for processing,
the gas and the pressure in the interior of each vacuum processing
chamber or other chambers are controlled in a decompressable
manner, and the chambers are connected to a vacuum transfer chamber
having a robot arm or the like for transferring the substrates
being processed.
[0007] According to such arrangement, the size of the whole body of
the vacuum processing chamber is determined by the size, the number
and the arrangement of the vacuum transfer chambers and the vacuum
processing chambers. The arrangement of the vacuum transfer
chambers is determined by the vacuum transfer chamber disposed
adjacent thereto or the number of vacuum processing chambers
connected thereto, the turning radius of the transfer robot
disposed therein, the wafer size, and so on. Further, the
arrangement of the vacuum processing chambers is determined by the
wafer size, the vacuum efficiency, or the arrangement of devices
required for wafer processing. Further, the arrangements of the
vacuum transfer chambers and the vacuum processing chambers are
also determined by the number of processing chambers required for
the process or the maintenance performances thereof.
[0008] Regarding the above demands, patent document 1
(International publication of International Application published
under the patent cooperation treaty No. 2007-511104) discloses
methods and systems for handling workpieces in a vacuum-based
semiconductor handling system, including methods and systems for
handling materials from arm to arm in order to traverse a linear
handling system. The disclosure of patent document 1 aims at
solving the problems of a linear tool while answering to the
demands for realizing a semiconductor processing apparatus capable
of overcoming the restrictions specific to a cluster tool, to
thereby provide a vacuum processing system capable of having wafers
transferred therein with a small footprint.
SUMMARY OF THE INVENTION
[0009] The above-mentioned prior art aims at providing a method and
system for transferring wafers, but the following problems were not
sufficiently considered.
[0010] The prior art lacked to consider the number and relationship
of arrangement of the units constituting the vacuum processing
system, which are vacuum transfer chambers for transferring wafers
in vacuum and the vacuum processing chambers for processing wafers
as the objects to be processed, so that the production efficiency
thereof is optimized. As a result, the productivity per footprint
of the apparatus was not optimized.
[0011] According to the prior art in which the productivity per
footprint is not sufficiently considered, the wafer processing
ability per footprint of the apparatus constituting the vacuum
processing system had been deteriorated.
[0012] Therefore, the object of the present invention is to provide
a vacuum processing system and a vacuum processing method for
semiconductor substrates in which a high productivity per footprint
is realized.
[0013] In order to solve the above-mentioned problems of the prior
art, the present invention provides a vacuum processing system of a
semiconductor processing substrate comprising an atmospheric
transfer chamber having a plurality of cassette stands arranged on
a front side thereof for transferring a wafer stored in a cassette
disposed on one of the plurality of cassette stands, a lock chamber
arranged on a rear side of the atmospheric transfer chamber for
storing in an interior thereof the wafer transferred from the
atmospheric transfer chamber, a first vacuum transfer chamber
connected to a rear side of the lock chamber to which the wafer
from the lock chamber is transferred, a transfer intermediate
chamber connected to a rear side of the first vacuum transfer
chamber, a second vacuum transfer chamber connected to a rear side
of the transfer intermediate chamber to which the wafer from the
transfer intermediate chamber is transferred, at least one vacuum
processing chamber connected to a rear side of the first vacuum
transfer chamber for processing the wafer transferred thereto from
the first vacuum transfer chamber, and two or more vacuum
processing chambers connected to a rear side of the second vacuum
transfer chamber for processing the wafer transferred thereto from
the second vacuum transfer chamber, wherein the number of vacuum
processing chambers connected to the first vacuum transfer chamber
is smaller than the number of vacuum processing chambers connected
to the second vacuum transfer chamber.
[0014] Further, the vacuum processing system of a semiconductor
processing substrate comprises a first vacuum processing chamber
connected to the first vacuum transfer chamber for processing the
wafer transferred thereto from the first vacuum transfer chamber
and a second and third vacuum processing chambers connected to the
second vacuum transfer chamber for processing the wafer transferred
thereto from the second vacuum transfer chamber are provided,
wherein the number of vacuum processing chambers connected to the
first vacuum transfer chamber is one, and the number of vacuum
processing chambers connected to the second vacuum transfer chamber
is two.
[0015] According even further to the vacuum processing system of a
semiconductor processing substrate, a transfer robot is disposed
respectively in the first and second vacuum transfer chambers, and
each transfer robot comprises a plurality of arms.
[0016] Moreover, the present invention provides a vacuum processing
method for processing a semiconductor processing substrate using a
vacuum processing system of a semiconductor processing substrate
comprising an atmospheric transfer chamber having a plurality of
cassette stands arranged on a front side thereof for transferring a
wafer stored in a cassette disposed on one of the plurality of
cassette stands, a lock chamber arranged on a rear side of the
atmospheric transfer chamber for storing in an interior thereof the
wafer transferred from the atmospheric transfer chamber, a first
vacuum transfer chamber connected to a rear side of the lock
chamber to which the wafer from the lock chamber is transferred, a
transfer intermediate chamber connected to a rear side of the first
vacuum transfer chamber, a second vacuum transfer chamber connected
to a rear side of the transfer intermediate chamber to which the
wafer from the transfer intermediate chamber is transferred, a
plurality of vacuum processing chambers connected to a rear side of
the first vacuum transfer chamber for processing the wafer
transferred thereto from the first vacuum transfer chamber, and a
plurality of vacuum processing chambers connected to a rear side of
the second vacuum transfer chamber for processing the wafer
transferred thereto from the second vacuum transfer chamber,
wherein transfer of the wafer is controlled so as to use a single
vacuum processing chamber out of the plurality of vacuum processing
chambers connected to the first vacuum transfer chamber.
[0017] Further according to the vacuum processing method of a
semiconductor processing substrate of the present invention, a
transfer robot is disposed in the first vacuum transfer chamber and
the second vacuum transfer chamber respectively, each transfer
robot comprising a plurality of arms, and transfer of the wafer via
the transfer robot is controlled so as to use a single vacuum
processing chamber out of the plurality of vacuum processing
chambers connected to the first vacuum transfer chamber.
[0018] The present invention enables to provide a vacuum processing
system and a vacuum processing method of a semiconductor processing
substrate, having a high productivity per footprint.
[0019] Further, the present invention enables to provide a vacuum
processing system and a vacuum processing method of a semiconductor
processing substrate capable of suppressing the amount of generated
particles and preventing the occurrence of cross-contamination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is an explanatory view showing an outline of the
overall arrangement of a vacuum processing system including a
vacuum processing apparatus according to a first embodiment of the
present invention;
[0021] FIG. 2A is an enlarged view showing the vacuum transfer
chamber according to the embodiment illustrated in FIG. 1, wherein
the robot arm is retracted;
[0022] FIG. 2B is an enlarged view showing the vacuum transfer
chamber according to the embodiment illustrated in FIG. 1, wherein
the robot arm is extended; and
[0023] FIG. 3 is an explanatory view showing an outline of the
overall arrangement of the whole vacuum processing system including
the vacuum processing apparatus according to another embodiment of
the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Now, the preferred embodiments of a vacuum processing system
and a vacuum processing method for processing a semiconductor
substrate according to the present invention will be described in
detail with reference to the drawings.
[0025] FIG. 1 illustrates an outline of the overall arrangement of
the vacuum processing system including a plurality of vacuum
processing chambers according to a first embodiment of the present
invention.
[0026] A vacuum processing system 100 including a plurality of
vacuum processing chambers 103, 103 and 103 according to a first
preferred embodiment of the present invention shown in FIG. 1 is
mainly composed of an atmospheric block 101 and a vacuum block 102.
The atmospheric block 101 is a section for transferring in
atmospheric pressure and determining the storage positions of
semiconductor wafers as objects to be processed, and the vacuum
block 102 is a block for transferring wafers in a pressure
decompressed from atmospheric pressure and for processing the
wafers in the predetermined vacuum processing chamber 103. The
system 100 also comprises a lock chamber 105 in which the pressure
is increased and decreased between atmospheric pressure and vacuum
pressure while having a wafer stored therein, which is disposed
between the vacuum block 102 for transferring and processing wafers
and the atmospheric block 101.
[0027] The first preferred embodiment of the vacuum processing
system 100 according to the present invention relates to a system
configuration having a high productivity per footprint, wherein the
number of vacuum processing chambers 103 is three and the transfer
time in the vacuum block 102 is longer compared to the transfer
time in the atmospheric block 101. According further to the present
embodiment, the time required for processing a wafer in the vacuum
processing chambers 103 or the stay time of the wafer in the vacuum
processing chamber 103 is shorter than the time required for
transferring the wafer. Based on these conditions, the overall
processing time is restricted by the transferring process, and this
state is called a limited transfer rate.
[0028] The atmospheric block 101 has a substantially rectangular
solid shaped housing 106 storing an atmospheric transfer robot 109
therein, and on the front side of the housing 106 are disposed a
plurality of cassette stands 107, 107 and 107. Cassettes storing
wafers as objects to be processed or wafers for cleaning the vacuum
processing chamber 103 are placed on multiple cassette stands 107,
107 and 107.
[0029] A single lock chamber 105 is disposed adjacent to the
atmospheric block 101 in the vacuum block 102. The lock chamber 105
is disposed between a first vacuum transfer chamber 104 of the
vacuum block 102 and the atmospheric block 101, for varying the
inner pressure thereof between atmospheric pressure and vacuum
pressure while storing a wafer therein so as to transfer the wafer
between the atmospheric side and the vacuum side. The lock chamber
105 has a stage for loading two or more wafers in a vertically
stacked state. The first vacuum transfer chamber 104 has a
substantially rectangular planar shape having the interior thereof
decompressed, and has wafers transferred therein.
[0030] The first vacuum transfer chamber 104 can have vacuum
processing chambers 103 for processing the wafers connected to two
sides thereof. According to the first embodiment of the present
invention, the vacuum processing chamber 103 is connected to only
one of the two sides of the first vacuum transfer chamber 104.
Further, though the first vacuum transfer chamber 104 has a
substantially rectangular planar shape, the shape thereof can be
triangular or other polygonal shapes, or can be spherical.
Moreover, the other side of the first vacuum transfer chamber 104
comprises a vacuum transfer intermediate chamber 111 for
transferring wafers between a second vacuum transfer chamber 110.
The vacuum transfer intermediate chamber 111 also has a stage for
loading two or more wafers in a vertically stacked state, similar
to the lock chamber 105. Thus, it becomes possible to shorten the
transfer time, which takes up much of the overall processing
time.
[0031] Furthermore, a first vacuum transfer chamber 104 is
connected to one side of the vacuum transfer intermediate chamber
111, and a second vacuum transfer chamber 110 is connected to the
other side thereof. The second vacuum transfer chamber 110 also has
a substantially rectangular planar shape, and can have three vacuum
processing chambers 103 connected thereto, but according to the
present embodiment, there are two vacuum processing chambers 103
and 103 connected thereto. Further, the second vacuum transfer
chamber 110 has a substantially rectangular planar shape according
to the present embodiment, but it can have other polygonal
shapes.
[0032] Now, it is important that the number of vacuum processing
chambers 103 connected to the first vacuum transfer chamber 104
disposed on the front side is smaller than the number of vacuum
processing chambers 103 connected to the second vacuum transfer
chamber 110 disposed on the rear side of the system. According to
the present embodiment, the number of vacuum processing chambers
103 connected to the first vacuum transfer chamber 104 disposed on
the front side is one, and the number of vacuum processing chambers
103 connected to the second vacuum transfer chamber 110 disposed on
the rear side is two. According to the present invention, the
vacuum processing chamber 103 connected to the first vacuum
transfer chamber 104 disposed on the front side is called "a front
side vacuum processing chamber", and the vacuum processing chambers
103 and 103 connected to the second vacuum transfer chambers 110
disposed on the rear side are called "rear side vacuum processing
chambers".
[0033] The vacuum block 102 is a chamber capable of having the
interior thereof decompressed and maintained to a high degree of
vacuum.
[0034] The first vacuum transfer chamber 104 is a transfer chamber
for transferring wafers in the interior thereof. The first vacuum
transfer chamber 104 has disposed in a center area in the interior
thereof a vacuum transfer robot 108 (FIG. 2) for transferring
wafers in vacuum between the lock chamber 105 and the vacuum
processing chamber 103 or between the lock chamber 105 and the
vacuum transfer intermediate chamber 111. Similarly, the second
vacuum transfer chamber 110 has disposed in a center area in the
interior thereof a vacuum transfer robot 108 (FIG. 2) for
transferring wafers in vacuum between the vacuum transfer
intermediate chamber 111 and one of the two vacuum processing
chambers 103 and 103. The vacuum transfer robots 108 disposed in
the first vacuum transfer chamber 104 and the second vacuum
transfer chamber 110 supports a wafer on its arm and transfers the
wafer into or out of a wafer stage disposed in the vacuum
processing chamber 103, the lock chamber 105 or the vacuum transfer
intermediate chamber 111. Passages having a valve 120 that opens
and closes in an airtight manner are disposed between the first
vacuum transfer chamber 104 and the vacuum processing chamber 103,
the lock chamber 105 and the vacuum transfer intermediate chamber
111, respectively. Similarly, passages having a valve 120 that
opens and closes in an airtight manner are disposed between the
second vacuum transfer chamber 110 and the vacuum processing
chamber 103 and the vacuum transfer intermediate chamber 111,
respectively. These passages are opened and closed via the valve
120.
[0035] Next, we will describe an outline of the wafer transfer
process according to the vacuum processing method of a wafer for
processing a wafer via the vacuum processing system 100 arranged as
above.
[0036] A plurality of semiconductor wafers stored in a cassette
placed on either one of the plurality of cassette stands 107, 107
and 107 are subjected to processing either via the decision of a
control unit (not shown) for controlling the operation of the
vacuum processing system 100 or via a command from a control unit
(not shown) of a manufacturing line in which the vacuum processing
system 100 is installed. First, the atmospheric transfer robot 109
having received a command from the control unit takes out a
specific wafer from within a cassette, and transfers the wafer to
the lock chamber 105.
[0037] The lock chamber 105 to which the wafer is transferred and
stored has a valve 120 connected thereto closed in an airtight
manner with the transferred wafer stored in the chamber, and the
chamber is decompressed to a predetermined pressure. The lock
chamber 105 can store two or more wafers. Thereafter, the valve 120
disposed on the side facing the first vacuum transfer chamber 104
is opened, by which the lock chamber 105 is communicated with the
first vacuum transfer chamber 104, and the vacuum transfer robot
108 extends its arm to the interior of the lock chamber 105 and
transfers the wafer in the lock chamber 105 toward the first vacuum
transfer chamber 104. The first vacuum transfer chamber 104 can
have two or more wafers stored therein. The vacuum transfer robot
108 transfers the wafer loaded on its arm to either the vacuum
processing chamber 103 or the vacuum transfer intermediate chamber
111 determined in advance when the wafer is taken out of the
cassette.
[0038] According to the present embodiment, one of the multiple
valves 120 is selected to be opened and closed. In other words,
when the wafer is transferred from the first vacuum transfer
chamber 104 to the front-side vacuum processing chamber 103, the
valve 120 opening and closing the passage between the vacuum
transfer intermediate chamber 111 and the first vacuum transfer
chamber 104 and the valve 120 opening and closing the passage
between the lock chamber 105 and the first vacuum transfer chamber
104 are closed, while the valve 120 opening and closing the passage
between the front-side vacuum processing chamber 103 and the first
vacuum transfer chamber 104 is opened, by which the wafer is
transferred into the vacuum processing chamber 103. Moreover, when
the wafer carried into the vacuum transfer intermediate chamber 111
is transferred toward the rear-side vacuum processing chamber 103,
the valve 120 opening and closing the passage between the vacuum
transfer intermediate chamber 111 and the first vacuum transfer
chamber 104 is closed, by which the vacuum transfer intermediate
chamber 111 is airtightly sealed. Thereafter, the valve 120 opening
and closing the passage between the vacuum transfer intermediate
chamber 111 and the second vacuum transfer chamber 110 is opened
and the vacuum transfer robot 108 disposed in the second vacuum
transfer chamber 110 is extended, so as to transfer the wafer into
the second vacuum transfer chamber 110. Next, the vacuum transfer
robot 108 transfers the wafer loaded on its arm to either one of
the predetermined two vacuum processing chambers 103 and 103
disposed on the rear side thereof.
[0039] After the wafer is transferred to any one of the vacuum
processing chambers 103 and 103 disposed on the rear side, the
valve for opening and closing the passage between that vacuum
processing chamber 103 and the second vacuum transfer chamber 110
is closed and the vacuum processing chamber 103 is airtightly
sealed. Thereafter, processing gas is introduced into the vacuum
processing chamber 103, and when the pressure within the vacuum
processing chamber 103 reaches a predetermined pressure, the wafer
is processed. The wafer processing performed in this vacuum
processing chamber 103 is the same as the process performed in the
vacuum processing chamber 103 disposed on the front side.
[0040] In any of the vacuum processing chambers 103, when the
termination of wafer processing is detected, the valve 120 opening
and closing the passage between that vacuum processing chamber 103
and the first vacuum transfer chamber 104 or the second vacuum
transfer chamber 110 connected thereto is opened, and the vacuum
transfer robot 108 within that transfer chamber sends the processed
wafer to the lock chamber 105 or the vacuum transfer intermediate
chamber 111 via an opposite route as when the wafer was transferred
into the vacuum processing chamber 103. When the wafer is
transferred from the rear side vacuum processing chamber 103 via
the vacuum transfer intermediate chamber 111 to the lock chamber
105, or when the wafer is transferred from the front-side vacuum
processing chamber 103 to the lock chamber 105, the valve 120
opening and closing the passage between the lock chamber 105 and
the first vacuum transfer chamber 104 is closed, the transfer
chamber of the first vacuum transfer chamber 104 is airtightly
sealed, and the pressure within the lock chamber 105 is raised to
atmospheric pressure.
[0041] Thereafter, the valve 120 on the inner side of the housing
106 is opened to communicate the inner side of the lock chamber 105
and the inner side of the housing 106 in atmospheric pressure, and
the atmospheric transfer robot 109 transfers the wafer from the
lock chamber 105 to the original cassette and the cassette is
returned to its original position of the cassette stand.
[0042] The present invention exerts its effect especially in the
case of a limited transfer rate in which the time required for
processing the wafer in the vacuum processing chamber 103 or the
stay time of the wafer in the vacuum processing chamber 103 is
shorter than the wafer transfer time. The vacuum processing system
according to the first preferred embodiment of the present
invention comprises a first vacuum transfer chamber 104 disposed on
the front side and the second vacuum transfer chamber 110 disposed
on the rear side, wherein the first vacuum transfer chamber 104
disposed on the front side has a single vacuum processing chamber
103 and the second vacuum transfer chamber 110 disposed on the rear
side has two vacuum processing chambers 103 and 103. In this case,
each of the first vacuum transfer chamber 104 and the second vacuum
transfer chamber 110 has disposed therein a vacuum transfer robot
with two arms. As described, by arranging a single vacuum
processing chamber 103 on the front side and two vacuum processing
chambers 103 and 103 on the rear side, the transfer wait time of
the processed wafer within the front-side vacuum processing chamber
103 is shortened, and a vacuum processing system having superior
productivity is realized.
[0043] FIGS. 2A and 2B are enlarged views of the first vacuum
transfer chamber 104 illustrated in FIG. 1. The vacuum transfer
robot 108 has a first arm 201 and a second arm 202 for transferring
the wafers. The robot has two arms according to the present
embodiment, but the number of arms can be three or four.
[0044] Each arm 201 and 202 has a structure in which multiple beam
members have both ends thereof connected via joints. Each arm 201
and 202 is designed so that multiple beam members are axially
supported in pivotable manner at both ends thereof, so that each
arm 201 and 202 is capable of pivoting and expanding or shrinking
in both the vertical and horizontal directions independently around
the axes on the base ends of the arms, respectively. According to
this arrangement, it becomes possible to independently control the
carrying in and carrying out of multiple wafers, and to enhance the
transfer performance by accessing multiple transfer destinations in
parallel or carrying in and carrying out two wafers
simultaneously.
[0045] FIG. 2A shows a state in which wafers are transferred into
the first vacuum transfer chamber 104 from separate locations via
arms 201 and 202. FIG. 2B shows a state in which the first arm 201
transfers a wafer to the vacuum processing chamber 103 and the
second arm 202 transfers a wafer to the lock chamber 105 in
parallel. In this case, unlike the case where wafers are
transferred one at a time and valves 120 are selectively opened one
at a time, two valves 120 and 120 required for accessing the
necessary chambers must be opened and closed simultaneously.
[0046] Even in such case, by adopting the vacuum processing system
100 having one vacuum processing chamber 103 disposed on the front
side and two vacuum processing chambers 103 and 103 disposed on the
rear side, the wafer processing efficiency per footprint can be
enhanced.
[0047] This is due to the following reasons. In the case of the
limited transfer rate mentioned earlier, when the time required for
transferring the wafer into the vacuum processing chamber 103 (the
time from the state where the vacuum transfer robot 108 holding the
wafer is at standby state in front of the vacuum processing chamber
103 to when the transfer of the wafer into the vacuum processing
chamber 103 is completed and the valve 120 is closed) is compared
with the time required for transferring the wafer into the vacuum
transfer intermediate chamber 111 (the time from the state where
the vacuum transfer robot 108 holding the wafer is at standby state
in front of the transfer intermediate chamber 111 to when the
transfer of the wafer into the transfer intermediate chamber 111 is
completed and the valve 120 is closed), the transfer time for
transferring the wafer into the vacuum transfer intermediate
chamber 111 is shorter. Therefore, when assuming that two vacuum
processing chambers 103 are connected to the front-side first
vacuum transfer chamber 104 and only one vacuum processing chamber
103 is connected to the rear-side second vacuum transfer chamber
110, the wafer transfer time within the first vacuum transfer
chamber 104 arranged on the front side becomes the bottleneck of
the overall transfer time of the vacuum processing system 100. On
the other hand, according to the first embodiment of the present
invention, the second vacuum transfer chamber 110 disposed on the
rear side becomes the bottleneck so as to prevent the first vacuum
transfer chamber 104 disposed on the front side from becoming the
bottleneck, according to which the overall processing efficiency of
the whole vacuum processing system 100 is prevented from being
deteriorated Therefore, the arrangement according to the present
embodiment enables to improve the wafer processing efficiency per
footprint.
[0048] According to the first preferred embodiment of the present
invention, the first vacuum transfer chamber 104 and the front-side
vacuum processing chamber 103 or the lock chamber 105 (or the
second vacuum transfer chamber 110 and the rear-side vacuum
processing chambers 103 or the vacuum transfer intermediate chamber
111) are communicated via valves 120 that open and close in an
exclusive manner, so that it becomes possible to suppress the
generation of particles and cross-contamination effectively.
[0049] According to the system configuration shown in FIG. 1, the
maximum number of physically connectable vacuum processing chambers
103 is five. However, according to the present invention, it is
important that the number of vacuum processing chambers 103
connected to the first vacuum transfer chamber 104 arranged on the
front side is smaller than the number of vacuum processing chambers
103 connected to the second vacuum transfer chamber 110 arranged on
the rear side. Therefore, the following embodiment illustrates an
operation example where the processing efficiency of wafers
equivalent to the first embodiment shown in FIG. 1 is obtained in a
case where four vacuum processing chambers are connected.
[0050] FIG. 3 illustrates an example in which one vacuum processing
chamber 103 is additionally connected to the first vacuum transfer
chamber 104 arranged on the front side of the first embodiment,
according to which two vacuum processing chambers 103 and 103 are
connected thereto. According to the second preferred embodiment,
either one of the two vacuum processing chambers 103 and 103
connected to the first vacuum transfer chamber 104 is selectively
used in response to the processing time for processing wafers.
Then, the multiple vacuum processing chambers 103 and 103 connected
to the second vacuum transfer chamber disposed on the rear side
farthest from the atmospheric transfer side is used for production,
to thereby achieve the same improved production efficiency as that
of embodiment 1 illustrated in FIG. 1.
[0051] However, if the wafer transfer time in the first vacuum
transfer chamber 104 disposed on the front side does not become a
bottleneck of the overall transfer time of the vacuum processing
system 100, which is not the object of the present invention, by
having a plurality of vacuum processing chambers 103 and 103
connected to the first vacuum transfer chamber 104 arranged on the
front side, the processing efficiency may be enhanced by using all
the vacuum processing chambers 103 and 103 disposed on the front
side, depending on the wafer processing time in the vacuum
processing chamber 103 or the stay time of the wafer in the vacuum
processing chamber 103. Therefore, the control unit (not shown)
disposed in the vacuum processing apparatus does not exclude an
operation for optimizing the production efficiency of the vacuum
processing chambers 103 in response to the processing time.
[0052] Even according to the second embodiment, only one of the
multiple valves 120 are selectively opened and closed. In other
words, the valve 120 opening and closing the passage between the
vacuum transfer intermediate chamber 111 and the first vacuum
transfer chamber 104, the valve 120 opening and closing the passage
between the lock chamber 105 and the first vacuum transfer chamber
104 and the valve 120 opening and closing the passage between the
front right side vacuum processing chamber 103 and the first vacuum
transfer chamber 104 are closed, and the valve 120 for opening and
closing the passage between the front left side vacuum processing
chamber 103 and the first vacuum transfer chamber 104 is opened, so
as to transfer a wafer to the front left side vacuum processing
chamber 103. Either one of the left and right vacuum processing
chambers 103 can be used arbitrarily. Further, after the wafer is
transferred to the vacuum transfer intermediate chamber 111, the
valve 120 opening and closing the passage between the first vacuum
transfer chamber 104 is closed, by which the vacuum transfer
intermediate chamber 111 is airtightly sealed. Thereafter, the
valve 120 for opening and closing the passage between the vacuum
transfer intermediate chamber 111 and the second vacuum transfer
chamber 110 is opened, the vacuum transfer robot 108 disposed in
the second vacuum transfer chamber 110 is extended, and the wafer
is transferred into the second vacuum transfer chamber 110. The
vacuum transfer robot 108 transfers the wafer loaded on its arm to
either one of the rear side vacuum processing chambers 103
determined in advance when the wafer is taken out of the
cassette.
[0053] After the wafer is transferred to any one of the rear side
vacuum processing chambers 103, the valve 120 opening and closing
the passage between the vacuum processing chamber 103 and the first
vacuum transfer chamber 104 is closed and the vacuum processing
chamber 103 is airtightly sealed. Thereafter, processing gas is
introduced into the vacuum processing chamber 103 and when the
pressure within the vacuum processing chamber 103 reaches a
predetermined pressure, the wafer is processed.
[0054] When it is detected that the processing of the wafer is
completed, the valve opening and closing the passage between the
first vacuum transfer chamber 104 or the second transfer chamber
110 connected to the above-mentioned vacuum processing chamber 103
is opened, and the vacuum transfer robot 108 transfer the processed
wafer toward the lock chamber 105 via the opposite route as when
the wafer was carried into the vacuum processing chamber 103. When
the wafer is carried into the lock chamber 105, the valve 120
opening and closing the passage between the lock chamber 105 and
the first vacuum transfer chamber 104 is closed, the transfer
chamber of the first vacuum transfer chamber 104 is airtightly
sealed, and the pressure within the lock chamber 105 is raised to
atmospheric pressure.
[0055] Thereafter, the valve 120 on the inner side of the housing
106 is opened to communicate the interior of the lock chamber 105
with the interior of the housing 106, and the atmospheric transfer
robot 109 transfers the wafer from the lock chamber 105 to the
original cassette and returns the wafer to the original position
within the cassette.
[0056] The present invention provides a vacuum processing method
capable of exerting a similar effect as the first embodiment by
connecting two vacuum processing chambers 103 and 103 to the first
vacuum transfer chamber 104 arranged on the front side as
illustrated in the second embodiment, by arbitrarily selecting and
using only one of the vacuum processing chambers 103 and 103
arranged on the front side.
* * * * *