Liquid processing apparatus and liquid processing method

A liquid processing apparatus comprises a liquid processing section for applying a liquid processing to wafers W, a carrier delivery section for delivering the carrier housing the wafers W, a carrier stock section capable of storing a plurality of carriers, an interface section for transferring the wafers W between the carrier stock section and the liquid processing section, a carrier transfer device for transferring the carrier, a wafer inspecting device for inspecting the wafers W within the carrier, and a carrier transfer device control section for controlling the carrier transfer device. The carrier transfer device control section controls the carrier transfer device such that the carrier, which has been judged to be capable of a liquid processing on the basis of the result of the inspection of the wafers W, is stored in the carrier stock section, and the liquid processing is started after completion of the inspection of a predetermined number of carriers.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid processing apparatus and a liquid processing method for applying a predetermined liquid processing to a substrate such as a semiconductor wafer.

2. Description of the Related Art

In the manufacturing process of a semiconductor device, a liquid processing apparatus is used for processing a semiconductor wafer (wafer) with a process solution such as a chemical solution or pure water so as to remove contaminants such as particles, organic contaminants and metal impurities from the wafer and for applying an etching treatment to the wafer.

With a prominent progress achieved in recent years in the miniaturization, degree of integration and mass production of semiconductor devices, the wafer size is increased from 200 mm Ø (8 inches) to 300 mm Ø (12 inches). As a result, the weight of the wafer itself is increased, and the carrier (container) housing the wafers is rendered bulky and heavy. For storing and transferring wafers of 300 mm Ø, used is a carrier horizontally housing, for example, 25 wafers a predetermined distance apart from each other. On the other hand, concerning the liquid processing of the wafer, it is desirable in terms of the productivity to process simultaneously as large number of wafers as possible. Such being the situation, employed is a method of processing, for example, 50 wafers in a single operation.

For subjecting 50 wafers of 300 mm Ø to a liquid processing, it is necessary to transfer the wafers housed in two carriers into a liquid processing apparatus. For example, 25 wafers housed substantially horizontal in a single carrier are taken out by using a wafer delivery device so as to be delivered to a posture changing device within the liquid processing apparatus. Then, additional 25 wafers housed in another carrier are delivered to the posture changing device by using the wafer delivery device. In the posture changing device, a total of 50 wafers are collectively changed from the horizontal posture into the vertical posture, and the 50 wafers that are held vertical are delivered to the wafer transfer device so as to be transferred into a liquid processing section. A predetermined liquid processing or a drying processing is applied to the wafers in the liquid processing section. After the liquid processing, the wafers are brought back to the two vacant carriers such that 25 wafers are housed in each of these vacant carriers by the procedures opposite to those in the process of transferring the wafers into the liquid processing sections.

However, a difficulty is brought about in the case where the wafers housed in two carriers are subjected to a liquid processing as a single lot. Specifically, where the predetermined number of wafers are not housed in the second carrier, though the wafers housed in the first carrier are transferred into the posture changing device without any problem, it is necessary for the wafers transferred previously into the posture changing device not to be subjected to the liquid processing and to be returned again from the posture changing device to the carrier for starting the processing for another lot, giving rise to the problem in respect of the loss of the liquid processing time.

It should also be noted that, where the wafers are transferred into and out of the carrier through a single position, it is necessary to move the vacant carrier, from which the wafers have been taken out, to a predetermined site and, then, to transfer another carrier housing the wafers to the wafer transfer site. Since a predetermined time is required for the carrier transfer, another problem is generated that the through-put is lowered.

What should also be noted is that, where the wafers are taken out of the carrier, in which the wafers are housed substantially horizontal, by using a wafer delivery device so as to be delivered to the posture changing device and, then, the wafers are delivered to a wafer transfer device for transferring into the liquid processing section or where the wafers are transferred in the opposite route, the number of required mechanisms is increased so as to increase the arranging area and, thus, to the problem of an enlarge footprint of the apparatus.

BRIEF SUMMARY OF THE INVENTION

A first object of the present invention is to provide a liquid processing apparatus and a liquid processing method, in which the liquid processing is applied for each lot while preventing the returning operation of the unprocessed wafer so as to improve the productivity. A second object of the present invention is to provide a liquid processing apparatus that permits improving the through-put by efficiently transferring the carrier. Further, a third object of the present invention is to provide a liquid processing apparatus that permits diminishing the footprint.

According to a first aspect of the present invention, there is provided a liquid processing apparatus comprising a liquid processing section for applying a predetermined liquid processing to a substrate; a carrier delivery section for delivering a carrier having a plurality of substrates housed therein; a carrier stock section capable of storing a plurality of carriers; a substrate transfer section for transferring the substrate into said liquid processing section; a carrier transfer device for transferring the carrier within said carrier stock section; a substrate inspecting device for inspecting the number and/or the housed state of substrates within the carrier; and a carrier transfer device control section for controlling said carrier transfer device such that the carrier is stored in said carrier stock section in the case where it is judged possible to apply a liquid processing to the substrate on the basis of the result of the inspection performed by said substrate inspecting device.

According to a second aspect of the present invention, there is provided a liquid processing apparatus comprising a liquid processing section for applying a predetermined liquid processing to a substrate; a carrier delivery section for delivering a carrier having a plurality of substrates housed therein substantially horizontal a predetermined distance apart from each other; a carrier stock section capable of storing a plurality of carriers; a substrate transfer section for transferring the substrate into said liquid processing section; a carrier transfer device for transferring the carrier within said carrier stock section; a substrate inspecting device for inspecting the number and/or the housed state of substrates within the carrier; and a carrier transfer device control section for controlling said carrier transfer device such that the carrier is stored in said carrier stock section in the case where it is judged possible to apply a liquid processing to the substrate on the basis of the result of the inspection performed by said substrate inspecting device;

wherein said substrate transfer section includes a substrate delivery device for delivering substrates into and out of the carrier; a substrate transfer device for delivering substrates into and out of said liquid processing section; and a substrate transplanting device for delivering the substrates in a substantially horizontal state into and out of said substrate delivery device and for delivering the substrates in substantially a vertical state into and out of said substrate transfer device.

According to a third aspect of the present invention, there is provided a liquid processing apparatus comprising a liquid processing section for applying a predetermined liquid processing to a substrate; a carrier delivery section for delivering a carrier having a plurality of substrates housed therein substantially horizontal a predetermined distance apart from each other; a carrier stock section capable of storing a plurality of carriers; a substrate transfer section for transferring the substrate into said liquid processing section; a carrier transfer device for transferring the carrier within said carrier stock section; a substrate inspecting device for inspecting the number and/or the housed state of substrates within the carrier; and a carrier transfer device control section for controlling said carrier transfer device such that the carrier is stored in said carrier stock section in the case where it is judged possible to apply a liquid processing to the substrate on the basis of the result of the inspection performed by said substrate inspecting device;

wherein said substrate transfer section includes a substrate transfer device for delivering substrates into and out of said liquid processing section; and a substrate delivery/posture changing device for delivering the substrate into and out of the carrier and for changing the posture of the held substrate between a substantially horizontal state and a substantially vertical state for delivery of the substrate into and out of said substrate transfer device.

According to a fourth aspect of the present invention, there is provided a liquid processing apparatus comprising a liquid processing section for applying a predetermined liquid processing to a substrate; a carrier delivery section for delivering a carrier having a plurality of substrates housed therein; a carrier stock section capable of storing a plurality of carriers; a carrier transfer device for transferring the carrier within said carrier stock section; a substrate inspecting device for inspecting the number and/or housed state of the substrates in the carrier; a carrier retreat device for transferring the carrier between the inspecting position where the inspection is performed by said substrate inspection device and a predetermined retreat position; a carrier transfer device control section for controlling said carrier transfer device such that the carrier is stored in said carrier stock section in the case where it is judged possible to apply a liquid processing to the substrate on the basis of the result of the inspection performed by said substrate inspecting device; and a substrate transfer section for transferring the substrate into said liquid processing section.

According to a fifth aspect of the present invention, there is provided a liquid processing method for applying a predetermined liquid processing to the substrates housed in a first carrier and a second carrier, comprising a first step for inspecting the number and/or housed state of the substrates within the first carrier; a second step for storing the first carrier within the carrier stock section in the case where it is judged by the inspection in said first step that it is possible to apply a liquid processing, and for stopping the liquid processing applied to the substrates stored in the first and second carriers in the case where it is judged by the inspection in said first step that the liquid processing should be stopped; a third step for inspecting the number and/or housed state of the substrates within the second carrier in the case where the first carrier is stored in the carrier stock section; and a fourth step for transferring the substrates within the second carrier to the liquid processing section in the case where it is judged by the inspection in said third step that the liquid processing can be applied, followed by transferring the substrates within the first carrier into the liquid processing section, or, where it is judged by the inspection in said third step that the liquid processing should be stopped, for stopping the liquid processing of the substrates within the second carrier.

According to a sixth aspect of the present invention, there is provided a liquid processing method for applying a liquid processing to predetermined substrates, comprising a first step for inspecting the number and/or housed state of the substrates within a carrier; a second step for storing in a carrier stock section the carrier which has been judged to be capable of the liquid processing in the inspection in said first step and stopping the liquid processing in respect of the carrier for which it has been judged in the inspection in said first step that the liquid processing should be stopped; a third step for carrying out said first step and said second step for a predetermined number of carriers; a fourth step for transferring another carrier from the carrier stock section in the case where the another carrier, which is to be processed in a pair with the carrier for which it has been judged in the inspection in said first step that the liquid processing should be stopped, is already stored in the carrier stock section; and a fifth step for starting the liquid processing that is applied to the substrates in the carrier after the number of carriers stored in the carrier stock section has reached the predetermined number.

Further, according to a seventh aspect of the present invention, there is provided a liquid processing apparatus comprising a liquid processing section for applying a predetermined liquid processing to a substrate; a carrier delivery section for delivering a carrier having a plurality of substrates housed therein substantially horizontal a predetermined distance apart from each other; a carrier stock section capable of storing a plurality of carriers; a substrate transfer section for transferring the substrate into said liquid processing section; and a carrier transfer device for transferring the carrier within said carrier stock section;

wherein said substrate transfer section includes a substrate transfer device for delivering the substrate into and out of said liquid processing section; and a substrate delivery/posture changing device for delivering the substrates into and out of the carrier and for changing the posture of the held substrate between a substantially horizontal state and a substantially vertical state thereby transferring the substrate into and out of said substrate transfer device.

In the liquid processing apparatus and the liquid processing method according to the first to sixth aspects of the present invention described above, the liquid processing can be started after confirmation of the number and/or housed state of substrates within a plurality of carriers constituting a certain lot. As a result, it is possible to eliminate the situation that, after the substrates are taken out of the first carrier and transferred to the liquid processing section, it is found that the processing cannot be performed because of, for example, the shortage of the substrates within the carrier. It follows that it is possible to eliminate the time loss required for the returning of the substrate from the liquid processing section back into the carrier, thereby improving the through-put.

It should also be noted that a carrier retreat device is arranged in the carrier stock section. Therefore, it is possible for the carrier transfer device to transfer the carrier that is to be subjected to the next inspection to a region in the vicinity of the inspecting position during inspection of the state of the substrates within a certain carrier. Soon after the inspected carrier is moved to a retreat position by the carrier retreat device, the carrier held by the carrier transfer device can be disposed on the inspecting position so as to start inspection of the state of the substrate. On the other hand, it is possible for the carrier transfer device to transfer the carrier held by the carrier retreat device back to the original storing position during inspection of the substrate, thereby improving the through-put.

Further, in the liquid processing apparatus according to the seventh aspect of the present invention, the mechanism for delivering the substrate into and out of the carrier and the mechanism for changing the posture of the held substrate between a substantially horizontal state and a substantially vertical state are made integral so as to provide a compact system, making it possible to decrease the footprint of the liquid processing apparatus. Also, since the number of times of delivery of the substrates is decreased, it is possible to obtain an additional effect of preventing a damage done to the substrate and to the apparatus.

DETAILED DESCRIPTION OF THE INVENTION

Some embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the embodiments described below, the technical idea of the present invention is applied to a liquid processing apparatus in which the transfer, liquid processing, and drying of semiconductor wafers are consistently carried out in a batch system.

FIG. 1is an oblique view showing the construction of a liquid processing apparatus1according to one embodiment of the present invention, andFIG. 2is a plan view of the liquid processing apparatus. As shown inFIGS. 1 and 2, the liquid processing apparatus1comprises mainly a delivery section2for transferring a carrier C having wafers W housed therein in a horizontal state or for storing the carrier C, a liquid processing section4for applying a liquid processing by using a predetermined chemical solution to the wafer W or for applying a drying processing to the wafer W, and an interface section3for transferring the wafer W between the delivery section2and the liquid processing section4.

The delivery section2comprises a carrier delivery section5and a carrier stock section6. A stage11for supporting the carrier C is arranged in the carrier delivery section5. The carrier C is constructed such that a plurality of wafers W, e.g., 25 wafers, can be housed in a substantially horizontal state a predetermined distance apart from each other in the carrier C. The transfer port of the wafer W, which can be opened or closed by a lid, is formed in one side surface of the carrier C. On the other hand, a plurality of carrier holding members13each capable of holding the carrier C are arranged in the carrier stock section6for storing the plural carriers C. The carrier C supported by the stage11and housing the wafers W before the liquid processing is transferred by a carrier transfer device12into the carrier stock section6. On the other hand, the carrier C housing the wafers W after the liquid processing is transferred by the carrier transfer device12from the carrier stock section6onto the stage11.

A shutter14is arranged between the carrier delivery section5and the carrier stock section6. The shutter14is kept closed in order to separate the atmosphere between the carrier delivery section5and the carrier stock section6, though the shutter14is opened only when the carrier C is transferred between the carrier delivery section5and the carrier stock section6.

The carrier transfer device12includes an arm12asuch as a multi-joint arm or a shrinkable arm, which is driven to permit at least the carrier C to be moved in an X-direction. The carrier C is held by the arm12aso as to be transferred. The carrier transfer device12can also be driven in a Y-direction and a Z-direction (height direction) by a Y-axis driving mechanism and a Z-axis driving mechanism so as to permit the carrier C to be disposed on a carrier holding member13arranged in a predetermined position.

InFIG. 2, the carrier holding members13are arranged in four points in the vicinity of the wall forming the carrier stock section6including an upper portion of an inspection/delivery stage15described herein later. The carrier holding member13in each point has a plurality of stages, e.g., four stages, in the height direction. The carrier stock section6temporarily stores the carrier C housing the wafer W before the liquid processing and the vacant carrier C from which the wafer W was taken out.

A window portion16is formed at the boundary between the carrier stock section6and the interface section3. An inspection/delivery stage15having the construction similar to that of the carrier holding member13is arranged on the side of the carrier stock section6of the window portion16. The carrier C is disposed on the stage15such that the lid of the carrier C faces the window portion16. Incidentally, it is possible to allow the carrier transfer device12to hold the carrier C for a predetermined time in a predetermined space facing the window portion16in place of arranging the inspection/delivery stage15.

A lid opening/closing mechanism17for opening/closing the lid of the carrier C disposed on the inspection/delivery stage15is arranged on the side of the carrier stock section6of the window portion16. The wafer W within the carrier C can be transferred toward the interface section3by keeping open the window portion16and the lid of the carrier C. By contraries, the wafer W can be transferred from the side of the interface section3into the vacant carrier C. Incidentally, it is possible to arrange the lid opening/closing mechanism17on the side of the interface section3of the window portion16.

A wafer inspecting device18for counting the number of wafers W within the carrier C is arranged on the side of the interface section3of the window portion16. The wafer inspecting device18, which comprises an infrared ray sensor head having a signal transmitting section and a signal receiving section, is scanned in the Z-direction in the vicinity of the edge in the X-direction of the wafer W housed in the carrier C so as to detect the signal of the transmitted light or reflected light of the infrared ray between the signal transmitting section and the signal receiving section, thereby detecting the number of wafers W. In addition to the function of detecting the number of wafers W, it is desirable for the wafer inspecting device18to perform the function of inspecting the housed state of the wafers W. For example, it is desirable for the wafer inspecting device18to perform the function of inspecting whether the wafers W are correctly arranged in parallel at a predetermined pitch within the carrier C, and whether the wafers W are not housed obliquely at different stages of the carrier C. Also, it is possible to construct the wafer inspecting device18such that the number of wafers W is detected after confirmation of the housed state of the wafers W.

Incidentally, the wafer inspecting device for inspecting only the number of wafers W is used in the case where, for example, it is known by experiences that the stage deviation of the wafer W within the carrier C scarcely takes place. On the other hand, the wafer inspecting device for inspecting only the housed state of the wafers W is used in the case where, for example, it is known by experiences that an error in the number of wafers W housed in the carrier C scarcely takes place.

The operations of the carrier transfer device12and the wafer inspecting device18are controlled by a carrier transfer device control section90. For example, the carrier transfer device control section90controls the carrier transfer device12such that, after the number of wafers W within the carrier C is inspected by the wafer inspecting device18, the carrier C is stored in the carrier stock section6. The carrier transfer device control section90is interlocked with the carrier transfer device12so as to control the opening/closing of the shutter14, the opening/closing of the window16, and the operation of the lid opening/closing mechanism17.

A wafer delivery device19, a wafer transplanting device21and a wafer transfer device22are arranged in the interface section3. The wafer transplanting device21comprises a posture changing mechanism21aperforming the wafer delivery with the wafer delivery device19and changing the posture of the wafer W, and a wafer vertical holding mechanism21bperforming the wafer delivery between the posture changing mechanism21aand the wafer transfer device22.

The wafer delivery device19takes out the wafer W within the carrier C through the window portion16and delivers the wafer W to the posture changing mechanism21a. Also, the device19receives the wafer W after the liquid processing from the posture changing mechanism21aand transfers the wafer W into the carrier C. The wafer delivery device19has two systems of arms, i.e., an arm19afor transferring the unprocessed wafer W and another arm19bfor transferring the wafer W after the liquid processing. These arms19aand19bare arranged a predetermined distance apart from each other in the Z-direction in conformity with the arranging pitch and the number of wafers W within the carrier C such that the plural wafers W housed in the carrier C can be collectively held by these arms19a,19b. In the state shown inFIG. 2, the arms19a,19bare slidable or shrinkable in the direction denoted by an arrow A and is movable in the Z-direction by a predetermined distance. Further, the entire wafer delivery device19is swingable in a θ-direction, with the result that it is possible for the arms19aand19bto gain access to any of the carrier C disposed on the inspection/delivery stage15and the posture changing mechanism21a.

The wafer delivery device19is driven as follows. In the first step, under the state that the arm19ais on the side of the wafer transplanting device21and the direction of the arrow A coincides with the X-direction, the arm19ais slid or elongated so as to be inserted below the wafer W. Then, the arm19ais moved upward by a predetermined distance so as to permit the wafer W to be held by the arm19a, followed by sliding the arm19ain the opposite direction or by shrinking the arm19aso as to take the wafer W out of the carrier C. Then, the entire wafer delivery device19is swung by 90° in the counterclockwise direction inFIG. 2so as to permit the direction of arrow A to coincide with the Y-direction and to allow the arm19ato be positioned on the side of the liquid processing section4. Under this condition, the arm19ais slid or elongated so as to deliver the wafer W held on the arm19ato the posture changing mechanism21a.

On the other hand, under the state that the direction of the arrow A coincides with the Y-direction and the arm19bis positioned on the side of the liquid processing section4, the arm19bis slid or elongated so as to take out the wafer W after the liquid processing from the posture changing mechanism21a, followed by swinging the entire wafer delivery device19by 90° in the clockwise direction inFIG. 2so as to permit the direction of the arrow A to coincide with the X-direction and to permit the arm19bto be positioned on the side of the wafer transplanting device21. Under this condition, the arm19bis slid or elongated so as to transfer the wafer W held by the arm19binto the vacant carrier C.

The wafer W is held substantially horizontal when the wafer W is transferred by the wafer delivery device19. However, since it is necessary to keep the wafer W substantially vertical when the wafer W is washed, the posture of the wafer W is changed in the posture changing device21a. The posture changing device21aincludes, for example, a guide member having grooves or the like formed for holding the wafers W in conformity with the arranging pitch of the wafers W within the wafer delivery device19. The posture of the plural wafers W is changed from the horizontal state into the vertical state by swinging the guide member or the like holding the plural wafers W by about 90° in a predetermined direction. The wafers W held vertical in this fashion are once delivered onto the wafer vertical holding mechanism21bbefore the wafers W are delivered to the wafer transfer device22.

The wafer vertical holding mechanism21bincludes a groove portion capable of housing the wafers W at an arranging pitch half the wafer arranging pitch within the carrier C (seeFIGS. 8A and 8Breferred to herein later), with the result that a total of 50 wafers housed in two carriers C can be housed in the wafer vertical holding mechanism21b. It follows that the wafers W housed in two carriers C can be subjected to the liquid processing simultaneously. The wafer vertical holding mechanism21bis slidable between the position where delivery of the wafers W can be performed with the posture changing mechanism21aand the position where delivery of the wafers W can be performed with chucks28ato28cof the wafer transfer device22, and is constructed such that, when the wafer vertical holding mechanism21bis slid toward the wafer transfer device22while holding the wafers W, which are held substantially vertical, on the lower side of the wafers W, the mechanism21bdoes not collide against the chucks28ato28cof the wafer transfer device22.

The arranging pitch of the wafers W within the wafer transplanting device21is adjusted, for example, as follows. In the first step, 25 wafers are transplanted from the first carrier C into the posture changing mechanism21aby the wafer delivery device19. Then, the posture of the wafers W is changed from a substantially horizontal state into a substantially vertical state in the posture changing mechanism21aand, then, the wafers W are delivered into the wafer vertical holding mechanism21b. In this step, the arranging pitch of the wafers W delivered to the wafer vertical holding mechanism21bis equal to the arranging pitch within the carrier C. Then, 25 wafers are transplanted from the second carrier C into the posture changing mechanism21aby the wafer delivery device19. The posture of the wafers W is changed from the horizontal state into the vertical state in the posture changing mechanism21aand, then, the wafers W are delivered into the wafer vertical holding mechanism21b. In this step, the position of the wafer vertical holding mechanism21bis deviated by a distance equal to half the arranging pitch in the arranging direction of the wafers W, thereby allowing the wafer vertical holding mechanism21bto hold the wafers W at an arranging pitch half the arranging pitch within the carrier C.

The method of halving the arranging pitch of the wafers W is not limited to the method described above. For example, the posture changing mechanism21ais constructed to be capable of holding 50 wafers, which can be housed in two carriers C, at an arranging pitch half the arranging pitch within the carrier C. When the wafers W within the second carrier C are transplanted from the wafer delivery device19into the posture changing mechanism21a, the height of any one of the wafer delivery device19and the posture changing mechanism21ais deviated as a whole by half the arranging pitch of the wafers W within the carrier C. In this fashion, the posture of the 50 wafers held by the posture changing mechanism21ais collectively changed so as to deliver the 50 wafers W into the wafer vertical holding mechanism21b.

Also, for example, after the wafers W housed in a single carrier C are delivered into the posture changing mechanism21ain the arranging pitch equal to the arranging pitch of the wafers W within the carrier C, it is possible to change the arranging pitch of the wafers W at the timing of any of before and after the posture of the wafers W is changed from the horizontal state into the vertical state in the posture changing mechanism21a. It is also possible to mount a mechanism of adjusting the arranging pitch to the wafer vertical holding mechanism21b.

Further, it is possible to construct the posture changing mechanism21ato permit the wafer W to be swung by 90° in each of the forward direction and the reverse direction. In this case, the posture of the wafers W in the first carrier C is changed by the swinging in the forward direction within the posture changing mechanism21aand, then, these wafers W are delivered to the wafer vertical holding mechanism21b. On the other hand, the posture of the wafers W in the second carrier C is changed by the swinging in the reverse direction in the posture changing mechanism21aand, then, these wafers W are delivered to the wafer vertical holding mechanism21b. As a result, the processing surfaces of the wafers W on which resist films or the like are formed in the subsequent step are allowed to face each other in the wafer vertical holding mechanism21b. It should be noted that, if the posture of the wafers W in the second carrier C is changed by the swinging in the forward direction and, then, these wafers W are delivered to the wafer vertical holding mechanism21b, all the wafers delivered from the first and second carriers C into the wafer vertical holding mechanism21bare arranged such that the processing surfaces of the wafers W are allowed to face in the same direction.

The wafers W that are held vertical are transferred between the wafer transfer device22and the wafer vertical holding mechanism21b. To be more specific, the wafer transfer device22transfers the unprocessed wafer W into the liquid processing section4and takes the wafers after, for example, the liquid processing out of the liquid processing section4so as to deliver the processed wafers W into the wafer vertical holding mechanism21b. In the wafer transfer device22, the wafers W are held by three chucks28ato28c.

FIG. 3is a front view showing the positional relationship among the chucks28ato28cin the wafer transfer device22. A groove portion41, which is shown in detail inFIGS. 4A to 4Creferred to herein later, for holding the wafers W at a pitch equal to the arranging pitch of the wafers W held in the wafer vertical holding mechanism21bis formed in each of the chucks28ato28c. Among the chucks28ato28c, the central chuck28ais fixed to a table29and holds the wafers W at their lowermost ends. The remaining two chucks28band28care joined to rotary shafts42b,42cvia joining members43b,43c, respectively, and swung by a swinging mechanism (not shown) by a predetermined angle about the rotary shafts42b,42cin a manner to depict arcs on the Z-X plane. The chucks28b,28care held open as denoted by dotted lines during delivery of the wafer W and is held closed as denoted by solid lines during transfer of the wafers W.

Under the open state of the chucks28band28cdenoted by the dotted lines, all the chucks28ato28care aligned to form a straight line in the X-direction. Under this state, a washing treatment is applied to the chucks28ato28cby a chuck washing mechanism26described herein later. The position at which the chucks28band28chold the wafer W is not limited to the position shown inFIG. 3. It is possible for the chucks28band28cto hold the wafer W at a position above or below the position shown inFIG. 3.

For the wafer delivery between the wafer vertical holding mechanism21band the wafer transfer device22, the wafer vertical holding mechanism21bis moved in the Y-direction toward the wafer transfer device22. Further, various other methods can be employed for the wafer delivery between the mechanism21band the device22. For example, it is possible to move the wafer vertical holding mechanism21bin the Z-direction toward the wafer transfer device22. It is also possible to arrange a transplanting mechanism (not shown) between the wafer vertical holding mechanism21band the wafer transfer device22. In addition, it is possible to change the arranging pitch of the wafers W within the wafer transfer device22without changing the arranging pitch of the wafers W in the wafer transplanting device21. In other words, it is possible to change or adjust the arranging pitch of the wafers W in any stage of the transfer process of the wafers W in the interface section3as far as the wafers W housed in two carriers C can be held at a predetermined pitch in the wafer transfer device22.

The wafer transfer device22is movable along a guide rail23in the X-direction so as to enter the liquid processing section4and to retreat from the liquid processing section4such that the delivery of the wafers W can be performed between the wafer transfer device22and the wafer vertical holding mechanism21band the wafers W can be transferred into the liquid processing section4. Also, in order to confirm whether or not a damage or a positional deviation takes place in the wafer W after the liquid processing, an inspecting sensor27for inspecting the arranging state of the wafers W is arranged in the position where the delivery of the wafer W is performed between the wafer vertical holding mechanism21band the wafer transfer device22. Incidentally, the arranging position of the inspecting sensor27is not particularly limited as far as it is possible to perform the inspection before the wafer W after the liquid processing is transferred into the wafer delivery device19.

A parking area9ais formed in the interface section3in a position sideward of the position where the delivery of the wafer W is performed between the wafer vertical holding mechanism21band the wafer transfer device22. It is possible to hold, for example, the unprocessed wafers W in the parking area9a. For example, by utilizing the time during the wafers W of a certain lot are subjected to a liquid processing or drying processing, it is possible to transfer the wafers W of another lot to be subjected to a liquid processing in the next stage to the parking area9aby the wafer transfer device22. As a result, it is possible to shorten the moving time of the wafer W into a liquid processing unit7, compared with the case where the wafer W is transferred from, for example, the carrier stock section6, thereby improving the through-put.

The liquid processing section4comprises the liquid processing unit7, a drying unit8and a parking area9b. These drying unit8, liquid processing unit7and the parking area9bare arranged in the order mentioned as viewed from the interface section3. The wafer transfer device22is movable within the liquid processing section4along the guide rail23extending in the X-direction.

The unprocessed wafers W are held in the parking area9bas in the parking area9a. By utilizing the time during the wafers W of a certain lot are subjected to a liquid processing or drying processing, it is possible to transfer the wafers W of another lot to be subjected to a liquid processing in the next stage to the parking area9aby the wafer transfer device22. Since the parking area9bis contiguous to the liquid processing unit7, the moving time of the wafer W can be shortened in starting the liquid processing so as to improve the through-put.

As shown inFIG. 2, a first chemical solution tank31, a first water washing tank32, a second chemical solution tank33, a second water washing tank34, a third chemical solution tank35and a third water washing tank36are arranged in the liquid processing unit7in the order mentioned as viewed from the parking area9b. The liquid processing unit7also includes a first transfer device37for transferring the wafer W between the first chemical solution tank31and the first water washing tank32, a second transfer device38for transferring the wafer W between the second chemical solution tank33and the second water washing tank34, and a third transfer device39for transferring the wafer W between the third chemical solution tank35and the third water washing tank36.

Stored in the first chemical solution tank31is, for example, an SPM solution (i.e., a mixed solution consisting of concentrated sulfuric acid and hydrogen peroxide solution) heated at about 130° C. for removing an organic contaminant and metal impurities on the surface. Stored in the second chemical solution tank33is a chemical solution for removing the attached materials such as particles including, for example, a SC-1 solution (i.e., a mixed solution consisting of ammonia and hydrogen peroxide solution). Further, stored in the third chemical solution tank35is an etchant for etching the oxide film formed on the surface of the wafer W including, for example, a dilute hydrofluoric acid. In addition to the dilute hydrofluoric acid, it is also possible to use a mixture of hydrofluoric acid and ammonium fluoride (i.e., buffered hydrofluoric acid (BHF)), as the etchant.

The chemical solutions attached to the wafers W by the liquid processing performed in the first to third chemical solution tanks31,33and35are removed in the first to third water washing tanks32,34and36, respectively, by various water washing means such as an overflow rinsing or a quick dump rinsing.

The first transfer device37includes a driving mechanism movable in the Z-direction. The wafer W delivered from the wafer transfer device22is moved downward by the first transfer device37so as to be dipped in the first chemical solution tank31and pulled up a predetermined time later. Then, the wafer W is moved in parallel in the X-direction so as to be dipped in the first water washing tank32and, then, pulled up a predetermined time later. The wafer W processed in the first water washing tank32is once returned to the chucks28ato28cof the wafer transfer device22and, then, transferred from the wafer transfer device22into the second transfer device38. The second and third transfer devices38and39are equal to the first transfer device37in construction and operation. Incidentally, it is desirable for the delivery of the wafer W between the wafer transfer device22and the first to third transfer devices37to39to be carried out above the first to third water washing tanks32,34and36, respectively. Where the wafer transfer device22is stopped above the first to third chemical solution tanks31,33,35, it is possible for the wafer transfer device22to be contaminated with, for example, the vapor of the chemical solution so as to be damaged.

A water washing tank24and a chuck washing mechanism26for washing the chucks28ato28cof the wafer transfer device22are arranged in the drying unit8, and a drying chamber (not shown) supplied with, for example, the vapor of isopropyl alcohol (IPA) for drying the wafer W is arranged above the water washing tank24. Also, a transfer device25for transferring the wafer W between the water washing tank24and the drying chamber is arranged in the drying unit8. The wafer W washed with water in the water washing tank24is pulled up by the transfer device25so as to be dried by IPA in the drying chamber. The transfer device25is equal in construction to the first transfer device37, etc., except that the transfer device25is incapable of movement in the X-direction, and the delivery of the wafer W is performed between the transfer device25and the water transfer device22.

FIGS. 4A to 4Ccollectively show the construction of the chuck washing mechanism26, whereinFIG. 4Ais a plan view showing the chuck washing mechanism26,FIG. 4Bis a cross sectional view showing a washing nozzle51, andFIG. 4Cis a cross sectional view showing a drying nozzle54. The chuck washing mechanism26comprises the washing nozzle51, the drying nozzle54, a nozzle holding section52, a guide53, and a driving mechanism such as an air cylinder (not shown) for moving the nozzle holding section52along the guide53in the Y-direction. The washing nozzle51is provided with recesses shaped to cover the upper portions of the chucks28ato28carranged side by side in the X-direction. Also, formed within the washing nozzle51are a washing solution supply passageway51a, a washing solution discharge port51c, and a washing solution branched supply passageway51bcommunicating with the washing solution supply passageway51aand with the washing solution discharge port51c.

A washing solution is supplied from a washing solution supply source (not shown) into the washing solution supply passageway51a, and the washing solution is spurted at a predetermined angle from the washing solution discharge port51ctoward the groove portion41formed in the chucks28ato28c.FIG. 4Bshows that the washing solution discharge ports51care arranged at different angles depending on the chucks28ato28cthat are to be washed. These discharge ports51care arranged at different angles in view of the position of the groove portion41when the chucks28band28care moved down to the height equal to the height of the chuck28aand in view of the diffusing direction of the washing solution. The arranging angles of the washing water discharge ports51care not limited to those shown inFIG. 4B. It is possible to arrange the washing solution discharge ports51cat suitable angles in view of the shapes of the chucks28ato28c, and the shape and the forming position of the groove portion41.

The drying nozzle54is close in construction to the washing nozzle51. Specifically, formed within the drying nozzle54are a drying gas supply passageway54a, a drying gas discharge port54cand a drying gas branched supply passageway54bcommunicating with the drying gas supply passageway54aand with the drying gas discharge port54C. The positions and the number of the drying gas discharge ports54care determined appropriately such that the washing solution attached to the chucks28ato28care blown away by the drying gas discharged from the drying gas discharge ports54cso as to dry the entire chucks28ato28cand, thus, are not limited to the positions and the number shown inFIG. 4C. Incidentally, it is possible to permit the drying gas to be discharged from the washing nozzles51for drying the chucks28ato28cwithout arranging the drying nozzle54.

For operating the chuck washing mechanism26, the chucks28ato28care washed first by moving the washing nozzle51and the drying nozzle54from the state shown inFIG. 4Atoward the table29at a predetermined speed while discharging the washing solution. Then, if the washing nozzle51is moved to reach a predetermined position on the side of the table29after completion of the discharge of the washing solution against the entire region of the groove portion41, the position of the washing nozzle51is moved at a predetermined speed toward the tip portions of the chucks28ato28cwhile discharging a drying gas such as a nitrogen gas from the drying gas discharge ports54cso as to dry the chucks28ato28c. In this fashion, the chucks28ato28care washed and dried. It should be noted that the drying gas is blown from the side of the table29toward the tip portions of the chucks28ato28cfor drying the chucks28ato28c. As a result, it is possible to prevent the washing solution blown by the drying gas from being attached to, for example, the table29.

The operation of the liquid processing apparatus1of the construction described above will now be described with reference toFIG. 5showing a flow chart of the liquid processing. In the first step, the number of wafers to be processed, i.e., the number of carriers C, is determined (step1). In this example, two carriers C each housing 25 wafers W in a horizontal state forms a single lot, and 5 lots of wafers W are subjected to a liquid processing.

Two carriers C1and C2forming a single lot are disposed on the carrier delivery section5(step2). Then, the shutter14is opened, and the carrier C1is transferred into the carrier stock section6by using the carrier transfer device12(step3). It is desirable to close the shutter14after the carrier C1is transferred into the carrier stock section6so as to prevent dust, etc. from entering the carrier stock section6.

The carrier C1transferred into the carrier stock section6is disposed on the inspection/delivery stage5(step4), followed by opening the lid of the carrier C1by the lid opening/closing mechanism17and subsequently opening the window portion16, thereby inspecting the number and the housed state of the wafers W housed in the carrier C1by the wafer inspecting device18(step5).

Where an abnormality has not been detected in the housed state of the wafers W in the carrier C1, the window portion16and the lid of the carrier C1are closed, and the carrier C1is disposed on any of the carrier holding members13arranged in the carrier stock section6. The disposed position of the carrier C1is stored in the carrier transfer device control section90(step6). Then, the carrier C2is introduced into the carrier stock section6in accordance with steps3to6described above so as to inspect the housed state of the wafers W in the carrier C2. Where an abnormality has not been found, the carrier C2is also disposed on any of the carrier holding members13, and the disposed position is stored in the carrier transfer device control section90.

Where an abnormality has been found in the housed state of the wafers W in the carrier C1in step5, a liquid processing is not applied to the wafers W in the carrier C1, and the carrier C1is returned to the carrier delivery section5so as to remove the carriers C1and C2from the carrier delivery section5(step8). Also, where an abnormality has been found in the housed state of the wafers W in the carrier C2in step5, the carrier C2is returned to the carrier delivery section5. At the same time, the carrier C1, which was temporarily stored, is also returned to the carrier delivery section5. Then, the carriers C1and C2are removed from the carrier delivery section5(step8). The operations of steps2to8described above are also applied to the remaining carriers C, i.e., carriers C3to C10, (step9).

Since a predetermined time is required for the inspection of the number and housed state of the wafers W in the carrier C1, it is desirable to operate the carrier transfer device12to transfer successively the carriers C2to C10to predetermined positions within the carrier stock section6by utilizing the inspection time of the wafers W in stock C1such that, as soon as the inspection of the wafers W in the carrier C1is finished, the carrier C2housing the wafers W that are to be inspected in the next step are transferred from the stored position in the carrier stock section6into the inspection/delivery stage15.

It was customary in the past that, where an abnormality has not been found in the wafers W housed in the carrier C1, these wafers were transferred by the wafer delivery device19from the carrier C1into the wafer vertical holding mechanism21b, and the transfer of the wafers W housed in the carrier C2was awaited. In the conventional method, however, it was necessary to return the wafers W transferred to the wafer vertical holding mechanism21bback to the carrier delivery section5for housing these wafers W in the carrier C1in the case where it was necessary to suspend the liquid processing because, for example, the number of wafers W in the carrier C2was insufficient. As a result, the processing time was delayed.

Also, in the case where, for example, the number of wafers W housed in the next carrier C3is insufficient, though the liquid processing was finished without problem in respect of the wafers W housed in the carriers C1and C2, it is impossible to apply the liquid processing to the wafers W in the carriers C3and C4, resulting in failure to apply the liquid processing to the wafers in the 10 carriers C that were initially planned to be subjected to the liquid processing. In this case, it is necessary to prepare new wafers or to change the process conditions for the processing of the wafers W in the 8 carriers C. The occurrence of such a situation is undesirable in terms of the supervision of the production.

In the present invention, the state of the wafers W housed in all the carriers C is inspected in advance in the steps1to9described above and, then, the liquid processing is started, making it unnecessary to return the wafers W. Also, where the number of wafers W is insufficient, the process conditions are changed in advance so as to facilitate the supervision of the production.

After a predetermined number of carriers C housing the wafers W to be processed are stored in the carrier stock section6by the operations up to step9, the liquid processing of the wafers W is started. Since the position of the carrier C1is stored in the carrier transfer device control section90, the carrier transfer device12is operated to transfer the carrier C1from the stored position to the inspection/delivery stage15(step10). Then, the lid of the carrier C1is opened and the window portion16is also opened. Under this condition, the arm19afor transferring the unprocessed wafer, which is included in the wafer delivery device19, is operated so as to take the wafers W out of the carrier C1and to transfer these wafers W to a predetermined position of the interface section3(step11). Incidentally, when the wafers W are taken out of the carrier C1, the inspection by the wafer inspecting device18need not be performed because the state of the wafers W in the carrier C1is confirmed in advance. However, it is possible to perform the inspection by the wafer inspecting device18for reconfirmation.

After the wafers W were taken out of the carrier C1, the window portion16and the lid of the carrier C are closed in the carrier stock section6. Under this condition, the carrier transfer device12is operated so as to return the vacant carrier C1from the inspection/delivery stage15back to the original storing position. Also, the carrier C2is moved to the inspection/delivery stage15. It should also be noted that, in the interface section3, the wafer W held by the arm19ais delivered to the posture changing mechanism21a. The posture of the wafer W is changed in the posture changing mechanism21aand, then, the wafer W is delivered to the wafer vertical holding mechanism21b. The arm19ais then rendered capable of gaining access to the carrier C2disposed on the inspection/delivery stage15so as to take the wafers W out of the carrier C2and deliver the wafers thus taken out to the posture changing mechanism21a. The posture of the wafers W are changed in the posture changing mechanism21aand, then, the wafers W are delivered to the wafer vertical holding mechanism21b. In this fashion, 50 wafers W are arranged in the wafer vertical holding mechanism21bat a pitch half the arranging pitch of the wafers W housed in the carriers C1and C2.

The wafer vertical holding mechanism21bis slid toward the wafer transfer device22so as to transplant the wafers W onto the chucks28ato28c. Since it is possible to transfer the wafers W, which are to be subjected to the liquid processing in the next step, into the wafer vertical holding mechanism21bafter the wafers W are transplanted into the wafer transfer device22, it is desirable to transfer the wafers W in the carriers C3and C4into, for example, the parking area9bafter initiation of the liquid processing applied to the wafers housed in the carriers C1and C2as described herein later in preparation for the next operation.

The wafer transfer device22holding the wafers W is moved along the guide rail23to the position of the first chemical solution tank31or the first water washing tank32included in the liquid processing unit7so as to transplant the wafers W onto the first transfer device37. Then, the liquid processing of the wafer W is started (step12). The liquid processing of the wafer W is carried out by, for example, the dipping of the wafer W in the first chemical solution tank31, followed by the water wash in the first water washing tank32, the dipping of the wafer W in the second chemical solution tank33, followed by the water wash in the second water washing tank34, and the dipping of the wafer W in the third chemical solution tank35, followed by the water wash in the third water washing tank36, in the order mentioned.

After initiation of such a liquid processing of the wafer W, the waiting time of the wafer transfer device22is generated in the period between, for example, the dipping of the wafer W in the first chemical solution tank31and the water wash in the first water washing tank32. Therefore, the wafer W that is to be processed in the nest step is received from the wafer vertical holding mechanism21bso as to be transferred to the parking area9bby utilizing the waiting time noted above. Then, after the wafer W that was subjected first to the liquid processing is transplanted from the first water washing tank32into the second transfer device38, the next wafer W disposed in the parking area9bis transplanted into the first transfer device37so as to apply the liquid processing to the wafer W in the first chemical solution tank31.

The particular operation described above permits shortening the tact time and improving the through-put. The wafer W can be transferred to the parking area9bin view of the timing of returning the wafer after the liquid processing back to the carrier stock section6. It is possible to dispose the wafer W that is to be processed in the next step in the parking area9a. It is also possible to dispose the wafer W that is to be processed in the next step in the parking area9band to dispose the wafer W that is to be processed after the processing in the next step in the parking area9a.

The wafer W after the processing in the liquid processing unit7is once transplanted to the wafer transfer device22and, then, to the transfer device25of the drying unit8for the drying treatment. The wafer W after the drying treatment is transplanted into the wafer transfer device22so as to be returned back to the interface section3. Then, the state of the wafer W is inspected by the inspecting sensor27. If an abnormality has been detected in the state of the wafer W, a countermeasure is taken. For example, a maintenance is performed by stopping the liquid processing apparatus1. In this fashion, it is possible to prevent the damage done to the wafer transfer device22and the wafer vertical holding mechanism21bas well as the breakage of the wafer W that are caused by the erroneous delivery of the wafer W into the wafer vertical holding mechanism21b.

The wafer W returned to the interface section3after completion of the liquid processing can be housed in the vacant carriers C1and C2disposed on the inspection/delivery stage15by the procedures opposite to those in the process of transferring the unprocessed wafer W from the carrier stock section6into the wafer transfer device22(step13). The carriers C1and C2housing the wafers W after the liquid processing are transferred into the carrier delivery section5and, then, to the next step (step14). In the processing in the steps10to14described above, the wafers W that are to be subjected to the liquid processing are successively transferred into the liquid processing section4in view of the timing of the returning transfer of the wafer W after the liquid processing. After completion of the liquid processing of the wafers W in all the carriers C1to C10, the processing of the wafers W in another lot is started.

In the case of using another carrier C differing from the carrier C housing the wafers W before the liquid processing in housing the wafers W after the liquid processing in the carrier C, the vacant carrier C from which the wafers W have been taken out is transferred into the carrier delivery section5and a substitute carrier C is transferred into the carrier stock section6. It is also possible to transfer a vacant carrier C into the carrier stock section6for the temporary storing in the carrier stock section6and, then, to transfer the vacant carrier C into the carrier delivery section5in view of the time during which the carrier transfer device12need not be operated, followed by transferring another carrier C for housing the wafers W after the liquid processing into the carrier stock section6. The transfer and storage of the carrier C for housing the wafers W after the liquid processing in the carrier stock section6can be performed by utilizing the time before the wafers W after the liquid processing are returned to the inspection/delivery stage15.

A liquid processing apparatus according to another embodiment of the present invention will now be described.FIG. 6is a plan view showing the construction of a liquid processing apparatus100according to another embodiment of the present invention. The liquid processing apparatus100differs from the liquid processing apparatus1described previously in the constructions of the carrier stock section6and the interface section3and equal to the liquid processing apparatus1in the constructions of the other portions (units). To be more specific, the liquid processing apparatus100differs from the liquid processing apparatus1in that, in the apparatus100, a carrier retreat device60is newly arranged in the carrier stock section6, and that a wafer delivery/posture changing device70is arranged in the interface section3in place of the wafer delivery device19and the posture changing mechanism21ain the wafer transplanting device21. Such being the situation, the carrier retreat device60and the wafer delivery/posture changing mechanism70will now be described.

FIGS. 7A to 7Ccollectively show the construction of the carrier retreat device60arranged in the carrier stock section6. The carrier retreat device60is a mechanism for temporarily retreating the carrier C disposed on the inspection/delivery stage15into a region above the inspection/delivery stage15. In the following description, the position of the carrier C disposed on the inspection/delivery stage15is called an inspecting position, and a position above the inspecting position, to which the carrier C is moved upward by the carrier retreat device60for the temporary storage, is called a retreat position. The retreat position is not limited to a region above the inspecting position. For example, it is also possible for a region sideward of the inspecting position to constitute the retreat position.

The carrier retreat device60comprises a carrier holding section61for holding the carrier C, a slide arm62for sliding the carrier holding section61in the Y-direction, a guide63mounted to the wall of the carrier stock section6and extending in the Z-direction, and an arm holding section64holding the slide arm62and slidable along the guide63in the Z-direction. It is possible to use, for example, an air cylinder or a belt transfer mechanism as a driving mechanism (not shown) of the slide arm62and the arm holding section64.

In the liquid processing apparatus100, a carrier C′ having a projecting portion81, which is substantially T-shaped in cross section, formed on the upper surface as shown inFIGS. 7A to 7Cis used as the carrier C on condition that the carrier retreat device60is used. The projecting portion81comprises a columnar section81aand an umbrella section81b.

The carrier holding section61is substantially L-shaped. If the slide arm62is operated, the carrier holding section61gains access in the Y-direction to the projecting portion81on the upper surface of the carrier C′ in the inspecting position so as to be inserted into the clearance between the umbrella section81band the upper surface of the carrier C′, as shown inFIG. 7A. Then, if the arm holding section64is moved upward in the Z-direction along the guide63under the state that the carrier holding section61is kept inserted into the clearance between the umbrella section81band the upper surface of the carrier C′, as shown inFIG. 7B, the carrier holding section61abuts against the umbrella section81bso as to move upward the carrier C′ in the Z-direction, thereby moving the carrier C′ to the retreat position. Incidentally, the shape of the carrier holding section61is not limited to a substantial L-shape. For example, it is possible for the carrier holding section61to be substantially U-shaped as far as the carrier holding section61can be inserted into the clearance between the umbrella section81band the upper surface of the carrier C′.

As shown inFIG. 7C, the arm12aof the carrier transfer device12gains access to the lower side of the carrier C′ in the retreat position so as to hold the carrier C′. If the carrier holding section61is slightly moved downward such that the carrier holding section61does not abut against the umbrella section of the projecting portion81, or if the slide arm62is shrunk by slightly moving upward the arm12aof the carrier transfer device12, it is possible to withdraw the carrier holding section61from below the umbrella section81b. The carrier C′ held by the arm12aof the carrier transfer device12is transferred to the carrier holding member13in a predetermined position.

The wafer delivery/posture changing device70arranged in the interface section3will now be described in detail.FIGS. 8A and 8Bcollectively show the construction and operation of the wafer delivery/posture changing device70. The wafer delivery/posture changing device70comprises a plurality of support plates71arranged substantially in parallel a predetermined distance apart from each other, a plate holding section72for holding the support plates71, a wafer holding transfer guide73movably mounted on the side of the plate holding section72of the support plates71, a plate swinging mechanism74for collectively swinging the plural support plates71by a predetermined angle, a plate sliding mechanism75for sliding the support plates71in the X-direction, and a lift mechanism76for sliding the plate sliding mechanism75in the Z-direction.

The plate holding section72is joined to the plate sliding mechanism75by a joining tool82. InFIGS. 8A and 8B, a reference numeral77denotes a driving actuator for the plate sliding mechanism75, a reference numeral78denotes a driving actuator for the lift mechanism76, and a reference numeral79denotes a driving actuator for the wafer holding transfer guide73. The driving actuator79permits the two wafer holding transfer guides73to be slid simultaneously in the X-direction.

FIG. 9is a cross sectional view showing the construction of the support plate71. A support pin71aabutting against the wafer W is formed in a predetermined position on the front and back surfaces of the support plate71, and a holding pin71bis formed in substantially the tip portion of the support plate71on the side of the carrier stock section6. The tip of the holding pin71bis bent toward the plate holding section72. The wafer holding transfer guide73is slidable in the X-direction, and grooves73afor holding the wafers W are formed in the wafer holding transfer guide73on the side of the support plate71. These grooves73are formed at the positions and the pitch conforming with the positions and the pitch of the wafers W held by the support plates71.

The front and back sides of the support plate71are in symmetry in construction. Under the ordinary state, the wafer W is held by the surface caused to form the upper surface by the plate swinging mechanism74. It follows that it is possible to use, for example, the upper surface of the support plate71shown inFIG. 9for transferring the unprocessed wafer W, and the lower surface of the support plate71shown inFIG. 9to swing the support plate71to cause the lower surface to form the upper surface for transferring the wafer W after the liquid processing.

The wafer W under an abutting state against the support pin71acan be taken out of the carrier C′ by operating the plate sliding mechanism75to permit the support plate71to be inserted into the carrier C′ in the inspecting position and slightly moving upward the support plate71by operating the lift mechanism76, followed by withdrawing the support plate71from the carrier C′ from the particular state by operating the plate sliding mechanism75. If the wafer holding transfer guide73is slid from this state toward the tip portion of the support plate71, the wafer W is held by the holding pin71band the groove portion73aformed in the wafer holding transfer guide73. It follows that the movement of the wafer W is limited not only in the horizontal direction but also in the Z-direction.

Even if the plate swinging mechanism74is driven to swing the support plate71holding the wafer W by 90°, the wafer W is not disengaged from the support plate71and, thus, is not dropped. Also, since no member abuts against the lower end portion of the wafer W that is held substantially vertical, it is possible to transplant easily the wafer W onto the wafer vertical holding mechanism21b. In this case, the wafers W are held in the wafer vertical holding mechanism21bat the pitch equal to the arranging pitch of the wafers W within the carrier C′.

The wafers W can be transplanted from the wafer delivery/posture changing device70to the wafer vertical holding mechanism21bby, for example, moving downward the plate sliding mechanism75, etc. and the support plate71by operating the lift mechanism76so as to store the wafers W in the predetermined grooves83formed in the wafer vertical holding mechanism21b, and by moving upward the support plate71after the holding of the wafers W is released by retreating the wafer holding transfer guide73. The wafers W after the liquid processing can be transplanted from the wafer vertical holding mechanism21bto the wafer delivery/posture changing device70by the procedure opposite to that described above. However, careful attentions should be paid to the situation that the surface of the support plate71facing the wafer W form the predetermined surface for transferring the wafers W after the liquid processing.

It should be noted that the wafer vertical holding mechanism21bis slidable in the Y-direction. Therefore, the wafers W housed in two carriers C′ can be held in the wafer vertical holding mechanism21bat a pitch half the arranging pitch of the wafers W within the carrier C′, if the wafer vertical holding mechanism21bis slid in the Y-direction by a distance equal to half the arranging pitch of the wafers W within the carrier C′ when the wafers W in a certain carrier C′ are transplanted to the wafer vertical holding mechanism21band, then, the wafers W in another carrier C′ are transplanted to the wafer vertical holding mechanism21b. The wafers W are transplanted between the wafer vertical holding mechanism21band the wafer transfer device22as in the liquid processing apparatus1.

In the case of using the wafer delivery/posture changing device70, it is possible to decrease the arranging area of the apparatus, compared with the case of using the wafer delivery device19and the posture changing device21a, making it possible to decrease the footprint. Also, since the number of times of delivering the wafer W is decreased, it is possible to prevent the damage done to the wafer W and to the apparatus by the erroneous delivery.

How to transfer the carrier C′ within the carrier stock section6in the case of using the carrier retreat device60will now be described with reference toFIGS. 10A to 10I. The following description covers the case of transferring two carriers C′, i.e., carriers C1′ and C2′, housing the wafers because the liquid processing of the wafer W has not yet been started, and two additional carriers C′, i.e., carriers C3′ and C4′, which are rendered vacant because the liquid processing has already been started, under the state that at least four carriers C′ have already been transferred by the carrier transfer device12into the carrier stock section6so as to be disposed on the carrier holding members13in predetermined positions and the liquid processing has already been started in respect of the wafers W housed in predetermined carriers C′.

It is assumed that the wafers W housed in the carriers C1′ and C2′ have already been inspected to confirm that there is no abnormality when these carriers C1′ and C2′ are transferred into the carrier stock section6. For facilitating the description,FIGS. 10A to 10Ishow that the carriers C1′ to C4′ are positioned close to each other, and that the storing positions of the carriers C1′ to C4′ are close to the inspection/delivery stage15. However, these drawings do not show the actual storing positions of the carriers C1′ to C4′. Also, all the storing positions of the carriers C1′ to C4′ are not close to the inspection/delivery stage15. In other words, the carriers C1′ to C4′ are stored in the optional carrier holding members13.

FIG. 10Ashows the initial state. From this state, the carrier C1′ is transferred by the carrier transfer device12to the inspection/delivery stage15in order to transfer the wafers W housed in the carrier C1′ into the interface section3and, then, the wafers W are inspected again by the wafer inspecting device18by opening the lid of the carrier C1′ and the window portion16(FIG. 10B). Since the inspection takes a predetermined time, the carrier transfer device12transfers the carrier C2′ to a position close to the inspecting position by utilizing the inspecting time (FIG. 10B).

If it has been confirmed after inspection of the carrier C1′ that there is no abnormality, the wafers W are taken out of the carrier C1′ by the wafer delivery/posture changing device70, followed by closing the lid of the carrier C1′ and the window portion16and subsequently moving upward the carrier C1′ to the retreat position by operating the carrier retreat device60(FIG. 10C). Incidentally, the wafer delivery/posture changing device70should be put in a state that the wafers W taken out of the carrier C1′ can be transplanted into the wafer vertical holding mechanism21band that the device70is capable of gaining access to the carrier C2′ that is to be disposed on the inspection/delivery stage15in the next step.

Since the inspecting position, i.e., the inspection/delivery stage15, is rendered vacant by the movement of the carrier C1′ to the retreat position, the carrier transfer device12holding the carrier C2′ disposes the carrier C2′ on the inspection/delivery stage15. Then, the lid of the carrier C2′ and the window portion16are opened so as to inspect again the wafer W by using the wafer inspecting device18. Also, the carrier transfer device12receives the vacant carrier C1′ in the retreat position and returns the received vacant carrier C1′ back to the original storing position. Further, the carrier transfer device12holds the carrier C3′ and transfers the carrier C3′ from its storing position to a position close to the inspecting position (FIG. 10D).

If it has been confirmed after inspection of the carrier C2′ that there is no abnormality, the wafers W are taken out of the carrier C2′ by operating the wafer delivery/posture changing device70, followed by closing the lid of the carrier C2′ and the window portion16and subsequently moving upward the carrier C2′ to the retreat position by operating the carrier retreat device60(FIG. 10E). In the interface section3, the wafer delivery/posture changing device70transplants the wafers W taken out of the carrier C2′ to the wafer vertical holding mechanism21band further delivers the wafers W from the wafer vertical holding mechanism21bto the wafer transfer device22. The wafer transfer device22transfers the wafers W to the first transfer device37of the liquid processing section4or to the parking areas9aand9band, then, receives the wafers W after the liquid processing and the drying treatment from the transfer device25or the parking areas9aand9bso as to transplant the received wafers W to the wafer vertical holding mechanism21b. In this fashion, the apparatus should be rendered ready for transplanting the wafers W from the wafer vertical holding mechanism21bto the wafer delivery/posture changing device70.

In the carrier stock section6, the inspecting position is rendered vacant because the carrier C2′ is moved to the retreat position. Therefore, the carrier transfer device12holding the carrier C3′ disposes the carrier C3′ on the inspection/delivery stage15. Concerning the carrier C3′, the lid of the carrier C3′ and the window portion16are opened so as to transfer the wafers W after the liquid processing from the wafer delivery/posture changing device70into the carrier C3′, and the housed state of the wafers W are inspected by the wafer inspecting device18. Also, the carrier transfer device12receives the carrier C2′ in the retreat position from the carrier retreat device60and returns the received carrier C2′ to the original storing position. Further, the carrier transfer device12holds the carrier C4′ and transfers the carrier C4′, from the storing position to a position close to the inspecting position (FIG. 10F).

After the inspection in the carrier C3′ has been finished, the lid of the carrier C3′ and the window portion16are closed, and the carrier C3′ is moved to the retreat position by the carrier retreat device60(FIG. 10G). Then, the carrier transfer device12holding the carrier C4′ disposes the carrier C4′ on the inspection/delivery stage15, followed by receiving the carrier C3′ in the retreat position from the carrier retreat device60and returning the received carrier C3′ to the original storing position (FIG. 10H). In the inspecting position, the lid of the carrier C4′ and the window16are opened, and the wafers W after the liquid processing are transferred from the wafer delivery/posture changing device70into the carrier C4′ for inspection of the housed state of the wafers W by the wafer inspecting device18.

After the inspection of the carrier C4′ has been finished, the lid of the carrier C4′ and the window portion16are closed, and the carrier transfer device12transfers the carrier C4′ from the inspecting position to the original storing position (FIG. 10I), thereby finishing the predetermined processing applied to the wafers W housed in the carriers C1′ to C4′.

By arranging the carrier retreat device60as in the liquid processing apparatus100, the carrier transfer device12can be operated even while a certain carrier C is being inspected by the wafer inspecting device18so as to shorten the transfer time of the carrier C in the carrier stock section6and, thus, to improve the through-put.

The carrier C or C′ is transferred into the carrier stock section6and is moved within the carrier stock section6as described above in each of the liquid processing apparatuses1and100according to the embodiments of the present invention. However, the manner of transferring the carrier C or C′ into the carrier stock section6and moving the carrier C or C′ within the carrier stock section6is not limited to the manner described above.

When it comes to the case where two carriers C, i.e., first and second carriers C, are processed as a single lot in, for example, the liquid processing apparatus1, it is possible to employ any of the two methods described below in the case where the number of lots to be processed is not determined, though the combination of the carriers C is determined.

In the first method, the number and state of wafers housed in the first carrier C are inspected first and, where there is no problem, the first carrier C is stored in a predetermined position in the carrier stock section6. On the other hand, where the number of wafers has been found to be short in the inspection of the first carrier C, the first carrier C is returned to the carrier delivery section5, and the next lot is inspected without inspecting the second carrier C forming a pair with the first carrier C.

Where there is no problem in the first carrier C, the number and state of wafers housed in the second carrier C are inspected. Where there is no problem in the wafers W housed in the second carrier C, the wafer delivery device19transfers the wafers W from the second carrier C into the interface section3and, then, into the wafer vertical holding mechanism21b. After the vacant second carrier C, from which the wafers W were taken out, is disposed on any of the carrier holding members13arranged in the carrier stock section6, the first carrier C that were inspected previously is moved to the inspection/delivery stage15and the number and state of the wafers W are inspected again, as required. Then, the wafers W are transferred into the interface section3and, then, into the wafer vertical holding mechanism21b.

The 50 wafers W housed in the first and second carriers C held by the wafer vertical holding mechanism21bare transplanted into the wafer transfer device22so as to start the liquid processing. While the liquid processing is being carried out, the carrier C constituting the lot that is to be processed in the next step can be similarly inspected. On the other hand, the carriers after the inspection can be stored one by one in the carrier stock section6, or the wafers W can be transferred toward the parking areas9aand9b.

In the second method, the first carrier C and the second carrier C are stored first in predetermined positions within the carrier stock section6. Then, the first carrier C is moved to the inspection/delivery stage15so as to inspect the number and state of wafers W housed in the first carrier C. Where there is no problem, the first carrier C is returned to the original storing position within the carrier stock section6. Then, the second carrier C is moved to the inspection/delivery stage15so as to inspect the number and state of wafers W housed in the second carrier C. Where there is no problem, the second carrier C is returned again back to the original storing position within the carrier stock section6.

Where the number of wafers W has been found to be short in the inspection of the first carrier C, the first carrier C is transferred into the carrier delivery section5. The second carrier C is also transferred into the carrier delivery section5. Then, the inspection of the next lot is started.

Where there is no problem in any of the first and second carriers C, the first carrier C is moved first to the inspection/delivery stage15for inspection of the number and state of wafers W housed in the first carrier C, as required. Where there is no problem in the inspection, the wafer delivery device19takes the wafers W out of the first carrier C and transfers the wafers W taken out of the first carrier C to the wafer vertical holding mechanism21b. After the vacant first carrier C, from which the wafers W were taken out, is returned to the original storing position within the carrier stock section6, the second carrier C is moved to the inspection/delivery stage15for inspection again of the number and state of wafers W housed in the second carrier C, as required. Where there is no problem in the inspection, the wafer delivery device19takes the wafers W out of the second carrier C and transfers the wafers W thus taken out to the wafer vertical holding mechanism21b.

In this fashion, the 50 wafers W housed in the first and second carriers C held by the wafer vertical holding mechanism21bare transplanted onto the wafer transfer device22, and the liquid processing is started. While the liquid processing is being carried out, the carrier C constituting the lot that is to be processed in the next step can be similarly inspected. On the other hand, the carriers after the inspection can be stored in the carrier stock section6, or the wafers W can be transferred toward the parking areas9aand9b.

Where there are a plurality of additional carriers C housing wafers that are to be processed and a pair of carriers C forming a single lot are not formed in advance, it is possible to form a lot within the liquid processing apparatus1for recording the information. In this case, where there is no problem in the first carrier C such as shortage of the number of wafers, the wafers W are taken out of the first carrier C on the spot and transferred to the wafer vertical holding mechanism21b. The vacant first carrier C is stored in a predetermined position within the carrier stock section6. Where shortage in the number of wafers has been confirmed in the wafers W housed in the second carrier C, the second carrier C is returned to the carrier delivery section5or, after temporarily stored in the carrier stock section6, returned to the carrier delivery section5at a predetermined timing without applying a liquid processing to the wafers W housed in the second carrier C.

Where it has been confirmed in respect of the third carrier C that there is no shortage in the number of wafers W and that it is possible to start application of the liquid processing to the wafers W without problem, the wafers W are taken out of the third carrier C and transferred to the wafer vertical holding mechanism21b. In this fashion, a single lot is formed by the first and third carriers C and recording is made to that effect. It is possible to perform such a one-by-one processing by using the liquid processing apparatuses1and100.

In each of the embodiments described above, the technical idea of the present invention is applied to a semiconductor wafer. However, it is also possible to apply the technical idea of the present invention to other substrates such as a substrate for a liquid crystal display device (LCD).

The embodiments described above are simply intended to clarify the technical concept of the present invention. Of course, the present invention should not be limited to the embodiments described above in interpreting the technical scope of the present invention. The present invention can be worked in variously modified fashions within the spirit of the present invention and within the scope defined by the accompanying claims.