JP2019083337A - Substrate processing device, substrate transfer method, and computer-readable storage medium for storing substrate transfer program - Google Patents

Abstract

To improve throughput of a substrate processing device.SOLUTION: There are provided a substrate processing device, a substrate transfer method, and a substrate transfer program for, on the basis of a housing state of a substrate W housed in a carrier C, transferring the substrate W from the carrier C by using a first substrate transfer part 29 and a second substrate transfer part 30, therein when it is determined that the substrate W cannot be carried out of the carrier C by simultaneously driving the first substrate transfer part 29 and the second substrate transfer part 30 from the housing state of the substrate W, whether or not the substrate W can be carried out of the carrier C by driving only the second substrate transfer part 30 is determined, and when it is determined that the substrate W can be carried out of the carrier C by driving only the second substrate transfer part 30, the substrate W is carried out of the carrier C by driving only the second substrate transfer part 30.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a substrate processing apparatus and a substrate transfer method for transferring a substrate to and from a carrier containing a plurality of substrates, and a computer-readable storage medium storing a substrate transfer program.

  When manufacturing semiconductor components, flat panel displays and the like, a substrate processing apparatus is used to perform various processing such as cleaning processing and etching processing on a substrate such as a semiconductor wafer or a liquid crystal substrate.

  In this substrate processing apparatus, a plurality of (for example, 25) substrates before and after processing are carried in or out in a state of being accommodated in a carrier. The carrier is formed by arranging the substrate holding members holding the substrates horizontally one by one in the inside up and down, and horizontally holding the plurality of substrates at an interval in the vertical direction.

  The substrate processing apparatus is provided with a substrate storage state detection unit for detecting a storage state of the substrate stored in the carrier (for example, the distance between the upper and lower substrates, etc.). In addition, the substrate processing apparatus is provided with a substrate transfer unit for simultaneously transferring a plurality of (for example, five) substrates to and from the carrier (for example, refer to Patent Document 1).

  Then, in the substrate processing apparatus, when unloading the substrate from the carrier, the substrate accommodation state detection unit is used to detect the accommodation state of the substrate accommodated in the carrier. Thereafter, based on the detection result, it is determined whether or not a plurality of substrates can be simultaneously carried out of the carrier using the substrate transport unit. Thereafter, when it is determined that the substrates can be simultaneously carried out, forks provided for holding the substrates provided in the substrate conveyance unit are inserted between the substrates accommodated in the carrier, and the substrates are held by the respective forks. A plurality of substrates are carried out simultaneously from the carrier. On the other hand, when it is determined that the plurality of substrates can not be simultaneously unloaded from the carrier, the operator is notified, and the processing is stopped until the return work by the operator is completed.

JP, 2014-175608, A

  However, in the above-described conventional substrate processing apparatus, when it is determined that the plurality of substrates can not be simultaneously discharged from the storage state of the substrates stored in the carrier, the subsequent processing is temporarily stopped until the recovery work by the operator is completed. Therefore, the throughput of the substrate processing apparatus may be reduced.

Therefore, in the present invention, when it is determined from the detection result of the substrate accommodation state detection unit that the first substrate conveyance unit and the second substrate conveyance unit can be driven simultaneously to carry out the substrate from the carrier, (1) simultaneously driving the first substrate conveyance unit and the second substrate conveyance unit to carry out the substrate from the carrier, and simultaneously driving the first substrate conveyance unit and the second substrate conveyance unit to carry out the substrate from the carrier When it is determined that the second substrate transport unit can not be driven, it is determined whether the second substrate transport unit can be driven to determine whether the substrate can be unloaded from the carrier, and only the second substrate transport unit can be driven to unload the substrate from the carrier. When it was judged that it was possible, only the second substrate transport unit was driven to carry out the substrate from the carrier.
In addition, when it is determined that only the second substrate transport unit can not be driven out of the carrier to drive the substrate, the transport operation of the first substrate transport unit and the second substrate transport unit is stopped.
In addition, it is carried out depending on whether or not a space sufficient to insert a fork for holding a substrate provided in the first substrate conveyance unit or the second substrate conveyance unit between the substrates accommodated in the carrier is maintained. I decided to decide if I could do it.
In addition, it is stored whether the first substrate transport unit and the second substrate transport unit are used at the same time or only the second substrate transport unit is used when unloading the substrate from the carrier, and when unloading the substrate from the carrier, When only the second substrate transport unit is driven to unload the substrate from the carrier, also when loading the substrate into the carrier, only the second substrate transport unit is driven to load the substrate into the carrier.

  In the present invention, the throughput of the substrate processing apparatus can be improved.

The top view which shows a substrate processing apparatus. The plane sectional view (a) and side sectional view (b) which show a substrate accommodation state detection part. Side surface sectional drawing which shows a 1st and 2nd board | substrate conveyance part. 6 is a flowchart showing a substrate transfer program (when unloading a substrate). The flowchart which shows a board | substrate conveyance program (at the time of board | substrate carrying-in).

  Hereinafter, specific configurations of a substrate processing apparatus and a substrate transfer method (substrate transfer program) used in the substrate processing apparatus according to the present invention will be described with reference to the drawings. In the following description, a substrate processing system that functions as a substrate processing apparatus according to the present invention will be described as an example.

  FIG. 1 is a view showing a schematic configuration of a substrate processing system according to the present embodiment. In the following, in order to clarify the positional relationship, the X axis, the Y axis, and the Z axis orthogonal to one another are defined, and the positive direction of the Z axis is the vertically upward direction.

  As shown in FIG. 1, the substrate processing system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are provided adjacent to each other.

  The loading / unloading station 2 includes a carrier placement unit 11 and a transport unit 12. A plurality of substrates C, in the present embodiment, a plurality of carriers C accommodating a semiconductor wafer (hereinafter, wafer W) in a horizontal state are mounted on the carrier mounting portion 11.

  The transport unit 12 is provided adjacent to the carrier placement unit 11 and includes a substrate transport device 13 and a delivery unit 14 inside. The substrate transfer apparatus 13 includes a wafer holding mechanism that holds the wafer W. In addition, the substrate transfer apparatus 13 can move in the horizontal direction and the vertical direction and can pivot around the vertical axis, and transfer the wafer W between the carrier C and the delivery unit 14 using the wafer holding mechanism. Do.

  The processing station 3 is provided adjacent to the transport unit 12. The processing station 3 includes a transport unit 15 and a plurality of processing units 16. The plurality of processing units 16 are provided side by side on both sides of the transport unit 15.

  The transport unit 15 includes a substrate transport device 17 inside. The substrate transfer apparatus 17 includes a wafer holding mechanism that holds the wafer W. The substrate transfer device 17 can move in the horizontal and vertical directions and can pivot about the vertical axis, and transfer the wafer W between the delivery unit 14 and the processing unit 16 using the wafer holding mechanism. I do.

  The processing unit 16 performs predetermined substrate processing on the wafer W transferred by the substrate transfer device 17.

  The substrate processing system 1 further includes a control device 4. Control device 4 is, for example, a computer, and includes control unit 18 and storage unit 19. The storage unit 19 stores programs for controlling various processes performed in the substrate processing system 1. The control unit 18 controls the operation of the substrate processing system 1 by reading and executing the program stored in the storage unit 19.

  The program may be recorded in a storage medium readable by a computer, and may be installed in the storage unit 19 of the control device 4 from the storage medium. Examples of the computer-readable storage medium include a hard disk (HD), a flexible disk (FD), a compact disk (CD), a magnet optical disk (MO), and a memory card.

  In the substrate processing system 1 configured as described above, first, the substrate transfer device 13 of the loading / unloading station 2 takes out the wafer W from the carrier C placed on the carrier placement unit 11 and receives the taken-out wafer W Place it on the crossing section 14. The wafer W placed on the delivery unit 14 is taken out of the delivery unit 14 by the substrate transfer device 17 of the processing station 3 and carried into the processing unit 16.

  The wafer W carried into the processing unit 16 is processed by the processing unit 16, then carried out of the processing unit 16 by the substrate transfer device 17 and placed on the delivery unit 14. Then, the processed wafer W placed on the delivery unit 14 is returned to the carrier C of the carrier placement unit 11 by the substrate transfer device 13.

  Here, in the carrier C, as shown in FIG. 2, a thin plate-like substrate support 21 is formed inside the hollow box-like main body 20 opened at the rear. The substrate supports 21 are formed at three locations, such as the inner right and left side portions and the inner rear portion of the main body 20, at equal intervals in the vertical direction. Thus, the carrier C horizontally holds the plurality of wafers W at an interval in the vertical direction by supporting the edge portion of the wafer W from the bottom by the three substrate supports 21 arranged vertically. Can.

  The loading / unloading station 2 is also provided with a substrate accommodation state detection unit 22 for detecting the accommodation state of the wafer W accommodated in the carrier C. As shown in FIG. 2, the substrate accommodation state detection unit 22 horizontally connects the arm 24 with the light emitter 23 attached thereto and the arm 26 with the light receiver 25 attached thereto by the connector 27, and the elevator 27 is connected to the connector 27. It is attached. The substrate accommodation state detection unit 22 raises and lowers the light emitter 23 and the light receiver 25 by the elevation mechanism 28 to accommodate the wafer W accommodated inside the carrier C (for example, the upper and lower positions of each wafer W). And the thickness of each wafer W, the interval between the wafers W arranged vertically, and the like are detected.

  Further, the substrate transfer apparatus 13 is provided with first and second substrate transfer units 29 and 30 for transferring (loading and unloading) the wafer W between the carrier C and the delivery unit 14. The first and second substrate transfer units 29 and 30 are vertically aligned on the upper portion of the base 31. The base 31 is attached to an upper portion of a traveling body 32 capable of traveling in the Y direction inside the transport unit 12 via a support 33. The support 33 is connected to an elevation mechanism 34 for raising and lowering the base 31 (the first and second substrate transfer units 29 and 30) and a rotation mechanism 35 for rotating the base 31 (the first and second substrate conveyance portions 29 and 30).

  The first substrate transfer unit 29 has four forks 36 for holding the wafer W. The first substrate transport unit 29 is attached to the support 37 in a state in which four forks 36 are horizontally spaced at equal intervals in the vertical direction, and the first advancing and retracting mechanism 38 is attached to the support 37.

  The second substrate transfer unit 30 has only one fork 39 for holding the wafer W. The second substrate transport unit 30 is attached to the support 40 with the fork 39 in a horizontal state, and the second advancing and retracting mechanism 41 is attached to the support 40.

  The first and second substrate transfer units 29 and 30 arrange the forks 36 and 39 in the vertical direction at equal intervals. Thus, when the first substrate transfer unit 29 and the second substrate transfer unit 30 are simultaneously driven, up to five wafers W can be transferred simultaneously with the carrier C. Specifically, by simultaneously driving the first advancing and retracting mechanism 38 and the second advancing and retracting mechanism 41, the upper four forks 36 and the lower one fork 39 are simultaneously advanced to the inside of the carrier C, and further, The wafer W is supported by driving the lifting mechanism 34, and then the forks 36 and 39 are retracted from the inside of the carrier C by simultaneously driving the first advancing and retracting mechanism 38 and the second advancing and retracting mechanism 41. Thus, five wafers W can be simultaneously unloaded from the carrier C. During normal times, the five wafers W are simultaneously transported in consideration of throughput, but only the second substrate transport unit 30 is driven when it is desired to transport only one evaluation substrate or the like. The wafer W can be loaded onto the carrier C by the reverse operation of the above unloading operation.

  In the substrate processing system 1, as shown in FIG. 4, the wafer W is transported between the carrier C and the delivery unit 14 in the transport unit 12 in accordance with the substrate transport program stored in the storage unit 19.

  First, the substrate processing system 1 detects the storage state of the wafer W stored in the carrier C using the substrate storage state detection unit 22 (substrate storage state detection step S1).

  In this substrate accommodation state detection step S1, the control unit 18 drives the lift mechanism 28 to move the light emitter 23 and the light receiver 25 from the upper end to the lower end of the carrier C, and the light emitted from the light emitter 23 is received by the light receiver 25. Thus, the storage state of the wafer W is detected. Here, the substrate accommodation state detection unit 22 measures the vertical position of each wafer W accommodated in the carrier C, the thickness of each wafer W, and the distance between the wafers W arranged vertically, and stores these data in the storage unit 19. Remember.

  Next, the substrate processing system 1 determines whether the wafer W can be unloaded from the carrier C by using the first substrate transfer unit 29 and the second substrate transfer unit 30 simultaneously (first determination step S2). ).

  In the first determination step S2, all the forks 36 and 39 of the first and second substrate transport units 29 and 30 are accommodated in the carrier C based on the substrate accommodation state data stored in the storage unit 19 by the control unit 18 It is judged by whether it can be inserted between the wafers W lined up and down. That is, when all the forks 36 and 39 of the first and second substrate transfer units 29 and 30 are simultaneously inserted between the wafers W lined up and down accommodated in the carrier C, one of the forks 36 and 39 When there is a possibility that the clearance between the lower surface and the upper surface of the wafer W can not be maintained and there is a possibility of contact, the wafer W is unloaded from the carrier C using the first substrate transfer unit 29 and the second substrate transfer unit 30 simultaneously. I can not do that.

  If it is determined in the first determination step S2 that the wafer W can be unloaded from the carrier C using the first substrate transfer unit 29 and the second substrate transfer unit 30 simultaneously, the first substrate transfer unit 29 and At the same time, the five wafers W are unloaded from the carrier C simultaneously with the second substrate transport unit 30 and transported to the delivery unit 14 (first unloading step S3).

  On the other hand, when it is determined in the first determination step S2 that the wafer W can not be unloaded from the carrier C by using the first substrate transfer unit 29 and the second substrate transfer unit 30 simultaneously, the first and second It is determined whether or not the wafer W can be unloaded from the carrier C using only the second substrate transport unit 30 for the five wafers W that could not be unloaded by the substrate transport units 29 and 30 (second determination step) S4).

  In the second determination step S4, the fork 39 of the second substrate transfer unit 30 is arranged between the wafers W lined up and down accommodated in the carrier C based on the data of the substrate accommodation state stored in the storage unit 19 by the control unit 18 It is judged whether it can be inserted into That is, when the forks 39 of the second substrate transfer unit 30 are inserted between the wafers W lined up and down accommodated in the carrier C, the clearance between the lower surface of the forks 39 and the upper surface of the wafer W can not be maintained. If there is a possibility that the wafer W may come into contact with the substrate C, it is determined that the wafer W can not be unloaded from the carrier C using the second substrate transport unit 30.

  If it is determined in the second determination step S4 that the wafer W can be unloaded from the carrier C using the second substrate transport unit 30, then the total amount of the wafers C one by one from the carrier C using the second substrate transport unit 30. The five wafers W are unloaded and transferred to the delivery unit 14 (second unloading step S5).

  On the other hand, when it is determined in the second determination step S4 that the wafer W can not be unloaded from the carrier C using the second substrate transfer unit 30, the operator is notified by voice, light, etc. (notification step) S6).

  In the notification step S6, the transfer operation of the wafer W is stopped until it is released by the operator.

  The substrate processing system 1 performs the processing from the first determination step S2 to the notification step S6 described above for all the wafers W accommodated in the carrier C. At that time, the maximum number (in this case, five) of the wafers C accommodated in the carrier C can be transported by the first and second substrate transport units 29 and 30, and the first judgment is made for each section. The processing from step S2 to the notification step S6 is performed, and the processing is ended when the wafers W in all the sections have been unloaded (termination step S7).

  The substrate processing system 1 unloads the wafer W from the carrier C to the delivery unit 14 as described above. On the other hand, when the wafer W is transferred from the delivery unit 14 to the carrier C, the substrate processing system 1 simultaneously transfers five wafers W using the first substrate transfer unit 29 and the second substrate transfer unit 30 simultaneously. By doing this, the transport time can be shortened and the throughput can be improved. However, for example, when carrier C receives external pressure and substrate support 21 is deformed, the distance between upper and lower wafers W can not be maintained at a certain level or more inside carrier C. In such a case, not only can five wafers W be simultaneously unloaded using the first substrate transport unit 29 and the second substrate transport unit 30 simultaneously when unloading the wafer W, but also the loading of the wafer W At the same time, contact between the forks 36 and 39 and the wafer W may occur, and the wafer W may not be carried in. Therefore, the first substrate carrier 29 and the second substrate carrier 30 are simultaneously used to carry five wafers W simultaneously. Can not do it. Therefore, when the wafer W is unloaded from the carrier C, only the second substrate transfer unit 30 is driven to unload the wafer W from the carrier C (when the second unloading step S5 is performed), the wafer is transferred to the carrier C. Also when loading W, only the second substrate transfer unit 30 is driven to load the wafer W onto the carrier C. Thereby, the wafer W can be reliably carried into the carrier C.

  Specifically, as shown in FIG. 5, the substrate processing system 1 uses the first and second substrate transfer units 29 and 30 simultaneously when unloading the wafer W from the carrier C or only the second substrate transfer unit 30. Is stored in the storage unit 19, and when the wafer W is transferred from the delivery unit 14 to the carrier C, the storage at the time of unloading is called from the storage unit 19, and the first and second substrate transfer units 29 and 30 are stored. At the same time, it is determined whether the five wafers W have been simultaneously unloaded (third determination step S8).

  When five wafers W are simultaneously unloaded using the first and second substrate transport units 29 and 30 simultaneously, the carriers from the delivery unit 14 using the first and second substrate transport units 29 and 30 simultaneously At the same time, the five wafers W are loaded into C (first loading step S9). On the other hand, when the five wafers W are not simultaneously unloaded using the first and second substrate transport units 29 and 30 simultaneously (the wafers W were unloaded one by one using only the second substrate transport unit 30) In the case of (5), a total of five wafers W are carried in one by one from the delivery unit 14 onto the carrier C using the second substrate transfer unit 30 (second transfer-in step S10).

  The processing from the third determination step S8 to the second loading step S10 is performed for each section of the carrier C, and the processing is ended when the wafers W of all sections have been loaded (end determination step S11).

  As described above, in the substrate processing system 1, the first substrate transfer unit 29 and the second substrate transfer unit 30 are simultaneously driven from the storage state of the wafer W stored in the carrier C to move the carrier C to the wafer A case of unloading W and a case of unloading the wafer W from the carrier C by driving only the second substrate transfer unit 30 are selected. When it is determined that the first substrate transfer unit 29 and the second substrate transfer unit 30 can not be simultaneously driven out of the carrier C to drive the first substrate transfer unit 29 and the second substrate transfer unit 30, only the second substrate transfer unit 30 is driven. It is determined whether the wafer W can be unloaded from the carrier C, and when it is determined that the wafer W can be unloaded, only the second substrate transport unit 30 is driven to unload the wafer W from the carrier C. Thus, the transfer of the wafer W can be continuously performed even when the wafer W can not be unloaded from the carrier C in the related art, so that the throughput of the substrate processing system 1 can be improved. The number of wafers W transferable by the first substrate transfer unit 29 and the number of wafers W transferable by the second substrate transfer unit 30 may be the same. Further, when it is not necessary to transport only one wafer W, the number of wafers W that can be transported by the second substrate transport unit 30 may be plural. However, if the number of wafers W that can be transferred by the second substrate transfer unit 30 is smaller than the number of wafers W that can be transferred by the first substrate transfer unit 29, it is determined that unloading is possible in the second determination step S4. It is preferable that the number of wafers W that can be transferred by the second substrate transfer unit 30 is one, because the possibility of transfer is the highest.

W wafer (substrate)
C Carrier 1 substrate processing system (substrate processing equipment)
22 Substrate accommodation status detection unit
29 1st substrate transport unit
30 Second substrate transfer unit

Claims (13)

A substrate accommodation state detection unit for detecting the accommodation state of the substrate accommodated in the carrier;
A first substrate transport unit and a second substrate transport unit configured to transport the substrate to the carrier;
A control unit that controls the first substrate transfer unit and the second substrate transfer unit based on the detection result of the substrate accommodation state detection unit;
Have
From the detection result of the substrate accommodation state detection unit, the control unit determines that the first substrate conveyance unit and the second substrate conveyance unit can be driven simultaneously to carry out the substrate from the carrier Simultaneously driving the first substrate transport unit and the second substrate transport unit to carry out the substrate from the carrier;
On the other hand, when it is determined that the first substrate transport unit and the second substrate transport unit can not be simultaneously carried out to carry the substrate out of the carrier, only the second substrate transport unit is driven. If it is determined that the substrate can be unloaded from the carrier, and it is determined that only the second substrate transport unit can be driven to unload the substrate from the carrier, the second substrate transport unit A substrate processing apparatus characterized in that only the substrate is driven out of the carrier by driving.   The transfer operation of the first substrate transfer unit and the second substrate transfer unit when the control unit determines that it is not possible to drive the second substrate transfer unit and carry the substrate out of the carrier. The substrate processing apparatus according to claim 1, wherein:   The control unit has an interval sufficient to insert a fork for holding the substrates provided in the first substrate transfer unit and the second substrate transfer unit between the substrates accommodated in the carrier. 3. The substrate processing apparatus according to claim 1, wherein it is determined whether or not it can be carried out based on whether it is held or not. It is stored whether the first substrate transport unit and the second substrate transport unit are simultaneously used or only the second substrate transport unit is used when unloading the substrate from the carrier.
When only the second substrate transport unit is driven to unload the substrate from the carrier when unloading the substrate from the carrier, the second substrate transport unit also when loading the substrate into the carrier The substrate processing apparatus according to any one of claims 1 to 3, wherein control is performed so as to drive only the to carry the substrate into the carrier.   The substrate processing apparatus according to any one of claims 1 to 4, wherein the first substrate transport unit is configured to simultaneously transport more substrates than the second substrate transport unit.   The substrate processing apparatus according to claim 5, wherein the second substrate transport unit is configured to transport one sheet of the substrate. A first substrate transport unit that simultaneously transports a plurality of the substrates based on the storage status of the substrates stored in the carrier detected by the substrate storage status detection unit, and a second substrate transport unit that transports one of the substrates A substrate transfer method for transferring the substrate to the carrier using
When it is determined from the detection result of the substrate accommodation state detection unit that the first substrate conveyance unit and the second substrate conveyance unit can be driven simultaneously to carry out the substrate from the carrier, (1) simultaneously driving the first substrate transport unit and the second substrate transport unit to carry out the substrate from the carrier;
On the other hand, when it is determined that the first substrate transport unit and the second substrate transport unit can not be simultaneously carried out to carry the substrate out of the carrier, only the second substrate transport unit is driven. If it is determined that the substrate can be unloaded from the carrier, and it is determined that only the second substrate transport unit can be driven to unload the substrate from the carrier, the second substrate transport unit And driving the substrate from the carrier to drive the substrate.   When it is determined that only the second substrate transport unit can be driven to carry the substrate out of the carrier, the transport operation of the first substrate transport unit and the second substrate transport unit may be stopped. The substrate transfer method according to claim 7, characterized in that   Whether or not a space sufficient to insert a fork for holding the substrates provided in the first substrate transfer unit and the second substrate transfer unit between the substrates accommodated in the carrier is maintained 9. The substrate transfer method according to claim 7, wherein it is determined whether or not it is possible to carry out the substrate. It is stored whether the first substrate transport unit and the second substrate transport unit are simultaneously used or only the second substrate transport unit is used when unloading the substrate from the carrier.
When only the second substrate transport unit is driven to unload the substrate from the carrier when unloading the substrate from the carrier, the second substrate transport unit also when loading the substrate into the carrier The substrate transfer method according to any one of claims 7 to 9, wherein control is performed to drive only the to carry the substrate into the carrier.   The substrate transfer method according to any one of claims 7 to 10, wherein the first substrate transfer unit simultaneously transfers more substrates than the second substrate transfer unit.   The substrate transfer method according to claim 11, wherein the second substrate transfer unit transfers one sheet of the substrate. A substrate accommodation state detection unit for detecting the accommodation state of the substrate accommodated in the carrier;
A first substrate transport unit and a second substrate transport unit configured to transport the substrate to the carrier;
A computer readable storage medium storing a substrate transfer program for causing a substrate processing apparatus having the
When it is determined from the detection result of the substrate accommodation state detection unit that the first substrate conveyance unit and the second substrate conveyance unit can be driven simultaneously to carry out the substrate from the carrier, (1) simultaneously driving the first substrate transport unit and the second substrate transport unit to carry out the substrate from the carrier;
On the other hand, when it is determined that the first substrate transport unit and the second substrate transport unit can not be simultaneously carried out to carry the substrate out of the carrier, only the second substrate transport unit is driven. If it is determined that the substrate can be unloaded from the carrier, and it is determined that only the second substrate transport unit can be driven to unload the substrate from the carrier, the second substrate transport unit A computer readable storage medium storing a substrate transfer program, comprising: driving the substrate only from the carrier.

Images