JP3904843B2 - Substrate detection apparatus, substrate processing apparatus, and substrate detection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate detection device, and more particularly to a substrate detection device for detecting a glass substrate, a semiconductor wafer, or the like used in a liquid crystal display panel, a plasma display panel, or the like.
[0002]
The present invention relates to a substrate processing apparatus, and more particularly to a substrate processing apparatus that performs predetermined processing on glass substrates, semiconductor wafers, and the like used in liquid crystal display panels, plasma display panels, and the like.
[0003]
The present invention relates to a substrate detection method in a substrate processing apparatus, and more particularly to a substrate detection method in a substrate processing apparatus that performs predetermined processing on a glass substrate, a semiconductor wafer, or the like used for a liquid crystal display panel, a plasma display panel, or the like.
[0004]
[Prior art]
In a manufacturing process of a glass substrate (FPD substrate) for a liquid crystal display device or a plasma display device (PDP), a semiconductor wafer, etc., a substrate processing apparatus that forms a resist film on the surface of the substrate and performs exposure and development is necessary. . This substrate processing apparatus is an apparatus (inline system) that connects a plurality of processing units to enable consistent processing. For example, in a photolithography process, it is connected to an exposure machine to perform pre-coating cleaning, coating, exposure, and development. There is a coater / developer device that can continuously perform the above.
[0005]
In such a substrate processing apparatus, for example, in order to evaporate water droplets after cleaning the substrate, the substrate is heated with a hot plate, and then cooled with a cooling plate. When a substrate is heated or cooled by a hot plate or a cooling plate, the substrate is placed on the plate by a transfer device, and the substrate is lifted from the plate by the transfer device after the heating or cooling process. In such heating or cooling processing, it is preferable to perform heat treatment or transfer operation while confirming that the substrate is placed or lifted on the hot plate or cooling plate, and detects the presence or absence of the substrate on the plate. There is a need to. Conventionally, the distance between the substrate and the plate is detected by a sensor (for example, a photo sensor) embedded in the plate, and if the detected value is smaller than a preset threshold value, it is determined that the substrate is on the plate, and the detected value Is larger than a preset threshold value, it is determined that the substrate is lifted away from the plate (no substrate on the plate).
[0006]
[Problems to be solved by the invention]
By the way, when this type of substrate is subjected to heat treatment such as heating or cooling, the substrate warps due to the heat. When the substrate is warped, the distance between the substrate and the sensor increases even when the substrate is on the plate, and the substrate may not be detected. Although it is conceivable to increase the above threshold value in order to ensure detection of a warped substrate, the threshold value should be increased because it must be determined that there is no substrate when the substrate is lifted by the transport mechanism. There are also restrictions.
[0007]
In particular, glass substrates for liquid crystal display devices and PDPs have a large area and the warpage of the substrate is correspondingly large. If the glass substrate becomes larger or thinner in the future, the warpage of the substrate will become even larger. . If the amount of warpage when the substrate is on the plate is larger than the distance by which the substrate is lifted by the transport mechanism or the difference becomes so small that the two cannot be distinguished, the threshold value of the sensor as described above is increased. Therefore, substrate detection is impossible. In addition, this problem can be solved by the above-described method of appropriately setting the threshold if the distance by which the substrate is lifted by the transport mechanism is sufficiently large, but in reality, the time for transport cannot be increased or the apparatus The above-mentioned method cannot be employed due to the size limitation.
[0008]
An object of the present invention is to make it possible to reliably detect the state of placement and lifting of a substrate on a plate even when the substrate is warped.
[0009]
[Means for Solving the Problems]
A substrate detection device according to claim 1 is a substrate detection device that detects a state of a substrate placed on a placement table, a sensor that detects the presence height of the substrate at a specific position of the placement table, and a sensor detection First comparison means for comparing the result with the first threshold, second comparison means for comparing the sensor detection result with a second threshold different from the first threshold, and detection results of the first and second comparison means And evaluation means for judging the state of the substrate on the mounting table.
[0010]
Here, since the state of the substrate is evaluated using a plurality of threshold values, it is possible to reliably determine the mounting state of the substrate.
[0011]
According to a second aspect of the present invention, in the substrate detection apparatus according to the first aspect, the evaluation means evaluates the detection results of the first and second detection means to determine the state of warpage of the substrate.
[0012]
A substrate processing apparatus according to claim 3 is a substrate processing apparatus that performs a predetermined process on a substrate, and a substrate table on which the substrate can be mounted, and a substrate detection device that detects a state of the substrate mounted on the substrate table The substrate detection apparatus includes a sensor that detects the height of the substrate at a specific position on the mounting table, a first comparison unit that compares the detection result of the sensor with a first threshold, and a detection result of the sensor. A second comparing means for comparing with a second threshold different from the first threshold; and an evaluating means for evaluating the detection results of the first and second comparing means and judging the state of the substrate on the mounting table.
[0013]
Here, since the state of the substrate is evaluated using a plurality of threshold values, it is possible to reliably determine the mounting state of the substrate.
[0014]
A substrate processing apparatus according to a fourth aspect is the substrate processing apparatus according to the third aspect, wherein the evaluation means evaluates the detection results of the first and second detection means to determine the state of warpage of the substrate.
[0015]
A substrate processing apparatus according to a fifth aspect is the substrate processing apparatus according to the third or fourth aspect, wherein the transfer means is movable to a first position where the substrate is placed on the placement table and a second position where the substrate is lifted from the placement table. And a control means for controlling the transport means, and the evaluation means judges the state of the substrate on the mounting table with reference to the control state of the transport means by the control means.
[0016]
Thereby, it is possible to determine the state of the substrate and the state of warping on the mounting table while referring to whether the transporting state by the transporting unit is the substrate mounting state or the lifting state.
[0017]
A substrate processing apparatus according to a sixth aspect is the substrate processing apparatus according to the fifth aspect, wherein the first threshold value is a specific position when the maximum amount of warpage that may occur in the substrate placed on the placement table is possible. The second threshold value is the minimum value of the substrate height at a specific position when the transport means is lifted by moving to the second position.
[0018]
Accordingly, the state of the substrate can be reliably determined in consideration of the lifted state of the substrate and the warped state of the substrate.
[0019]
The substrate processing apparatus according to a seventh aspect is the substrate processing apparatus according to the sixth aspect, wherein the first threshold value can be set higher than the second threshold value.
[0020]
As a result, even when the amount of warping of the substrate is larger than the height of lifting by the transport means, it is possible to determine the state of the substrate reliably by setting them appropriately.
[0021]
A substrate processing apparatus according to an eighth aspect of the present invention is the substrate processing apparatus according to any one of the fifth to seventh aspects, wherein the transfer means is moved to the first position when the substrate processing apparatus is reset, and the first and second comparison means Evaluate the detection results. Thereby, it is confirmed that the evaluation result is “a state where no substrate exists on the mounting table”.
[0022]
A substrate detection method according to claim 9 is a substrate detection method for detecting a state of a substrate in a substrate processing apparatus that performs a predetermined process on a substrate placed on a mounting table, and includes first to third steps. Yes. In the first stage, it is detected whether or not the substrate exists within a first distance from the mounting table. In the second stage, it is determined whether or not the substrate exists within a second distance shorter than the first distance from the mounting table. In the third stage, the detection results in the first and second stages are evaluated to determine the state of the substrate. The substrate detection method according to the ninth aspect has the same effects as the substrate detection apparatus according to the first aspect.
[0023]
The substrate detection method according to a tenth aspect further includes a fourth step of evaluating the detection results of the first and second steps and evaluating the warpage of the substrate in the substrate detection method according to the ninth aspect. The substrate detection method according to the tenth aspect has the same effects as the substrate detection apparatus according to the second aspect.
[0024]
The substrate detection method according to an eleventh aspect is the substrate detection method according to the ninth or tenth aspect, wherein the substrate processing apparatus is movable between a first position where the substrate is placed on the placement table and a second position where the substrate is lifted from the placement table. And a control means for controlling the transport means. In the third stage, the state of the substrate on the mounting table is determined with reference to the control state of the transfer means by the control means. The substrate detection method according to the eleventh aspect has the same effects as the substrate processing apparatus according to the fifth aspect.
[0025]
A substrate detection method according to a twelfth aspect is the substrate processing apparatus according to the eleventh aspect, wherein the first distance is a specific position when a warp occurring in the substrate mounted on the mounting table is a maximum amount that can occur. The second distance is the minimum height of the substrate at the specific position and the distance between the mounting table when the transport means is lifted by moving to the second position. The substrate detection method according to the twelfth aspect has the same effects as the substrate processing apparatus according to the sixth aspect.
[0026]
In the substrate detection method according to the thirteenth aspect, the first distance is set longer than the second distance. The substrate detection method according to the thirteenth aspect has the same effects as the substrate processing apparatus according to the seventh aspect.
[0027]
A substrate detection method according to a fourteenth aspect is the substrate detection method according to any one of the eleventh to thirteenth aspects, wherein the transfer means is moved to the first position when the substrate processing apparatus is reset, and the first and second comparison means It further includes a fifth stage for evaluating the detection result. The substrate detection method according to the fourteenth aspect has the same effects as the substrate processing apparatus according to the eighth aspect.
[0028]
DETAILED DESCRIPTION OF THE INVENTION
[Substrate processing equipment]
One embodiment (first embodiment) of the substrate processing system of the present invention is shown in FIGS. FIG. 1 is a plan view of the substrate processing apparatus 1, and FIG. 2 is a block diagram of a substrate processing system including a control device 2 connected to the substrate processing apparatus 1.
[0029]
As shown in FIG. 1, the substrate processing apparatus 1 is a coater / developer apparatus in which a plurality of processing units are connected to enable consistent processing. The substrate processing apparatus 1 is connected to an exposure machine 2 and is applied before resist application in a photolithography process. It is designed to continuously perform from washing to coating / exposure / development.
[0030]
The substrate processing apparatus 1 includes processing units such as a cleaning unit 10, a dehydration bake unit 20, a coating unit 30, a prebake unit 40, an I / F unit 50, a development unit 60, a post bake unit 70, a conveyor unit 80, and an indexer unit 90. I have. The substrate processing apparatus 1 takes out a glass substrate to be processed (hereinafter referred to as a substrate) from the cassette 3 placed on the indexer unit 90, sends it to each processing unit, and stores the substrate after each processing step in the same cassette 3. Unicassette system can be adopted. Removal from the cassette 3 and storage in the cassette 3 are performed by an indexer robot 90R that is provided with an arm that can hold and turn a substrate and is movable along the row of the cassette 3.
[0031]
The cleaning unit 10 is a set of single-wafer processing units, and includes a carry-in unit, a water washing unit, a drying unit, and a carry-out unit. From the carry-in part to the carry-out part, the cleaning process is performed while the substrate is conveyed by a conveyor. In addition, a roller conveyor with a small dust generation property corresponding to the clean room is adopted as the conveyor. The dehydration bake unit 20 is a set of single-wafer processing units, and includes a carry-in unit, a heating unit, a cooling unit, and a carry-out unit. The heating unit includes a plurality of hot plates, and heats the substrate in stages with each plate. The cooling unit is composed of a plurality of cooling plates, and the substrate is cooled in stages with each plate. From the carry-in unit to the carry-out unit, heating and cooling processes are performed while the substrate is transported by a so-called intermittent transfer device that has a plurality of hands and sequentially feeds the substrate to the adjacent processing unit. The coating unit 30 is a set of single-wafer processing units, and includes a carry-in unit, a coating unit, a drying unit, an edge rinse unit, and a carry-out unit. The application unit is a device that applies a resist to the substrate, the drying unit is a device that dries the resist on the substrate, and the edge rinse unit is a device that removes the resist at the edge of the substrate. From the carry-in part to the carry-out part, resist coating, resist drying, and resist removal at the edge part are sequentially performed while the substrate is transported by the intermittent transfer device. The pre-bake unit 40 is a set of single-wafer processing units, and includes a carry-in unit, a heating unit, a cooling unit, and a carry-out unit. The heating unit is composed of a plurality of hot plates, and heats the substrate in stages with each plate. The cooling unit is composed of a plurality of cooling plates, and cools the substrate in stages with each plate. From the carry-in section to the carry-out section, heating and cooling processes are performed while the substrate is transferred by the intermittent transfer device. The developing unit 60 is a set of single-wafer processing units, and includes a carry-in unit, a developing unit, a water washing unit, a drying unit, and a carry-out unit. From the carry-in section to the carry-out section, development processing, cleaning processing, and drying processing are sequentially performed while the substrate is transported by the conveyor. The post bake unit 70 is a single wafer processing unit, and includes a carry-in unit, a heating unit, a cooling unit, and a carry-out unit. The heating unit includes a plurality of hot plates, and heats the substrate in stages with each plate. The cooling unit is composed of a plurality of cooling plates, and cools the substrate in stages with each plate. From the carry-in section to the carry-out section, heating and cooling processes are performed while the substrate is transferred by the intermittent transfer device. The conveyor unit 80 includes a conveyor for transporting the substrate, and the conveyor is connected to the conveyor of the carry-out section of the post-bake unit 70 and reaches the indexer section 90. The substrate sent out from the carry-out section of the post-bake unit 70 to the conveyor unit 80 is transported by the conveyor of the conveyor unit 80, is transported to the indexer section 90, is received by the indexer robot 90R, and is stored in the cassette 3 of the indexer section 90. Is done. The I / F unit 50 is a mechanism for transferring the substrates in order between the substrate processing apparatus 1 and the exposure machine 2. Generally, the I / F unit 50 is a transport robot for transporting the substrate or a buffer (cassette or the like) for adjusting the tact time. ).
[0032]
[Heating section and cooling section]
An example of a heating unit provided in the dewatering bake unit 20, the pre-bake unit 40, and the post-bake unit 70 is shown. FIG. 2 is a plan view, and FIG. 3 is a configuration block diagram. Since the structure of the cooling unit is the same as that of the heating unit, the following description is for cooling. Part Is also true.
[0033]
As shown in FIG. 2, the heating unit mainly includes hot plates 101 a to 101 c, conveyors 102 and 103, a movable frame 104, a conveying claw 105, and pushers 127 and 109 a to c and 128. The hot plates 101a to 101c are devices that heat a substrate placed on the plate. At the four corners of the hot plates 101a to 101c, pushers 109a to 109c are provided so as to be freely retracted and retracted from small holes formed on the surfaces of the hot plates 101a to 101c. These pushers 109a-c are the surfaces of the hot plates 101a-c. Et In this configuration, the substrate placed so as to protrude is lifted upward, and the substrate held downward is placed on the hot plates 101a to 101c. The conveyor 102 is a mechanism for delivering a substrate from the upstream processing unit to the foremost hot plate 101a, and the conveyor 103 is a mechanism for delivering the substrate from the last hot plate 101c to the downstream processing unit. is there. Pushers 127 and 128 are provided on the conveyors 102 and 103, respectively, and operate in the same manner as the above-described pushers 109a to 109c. The transport claw 105 rotates with respect to the substrate lifted by the pushers 127, 109a to c and 128, and enters the lower side thereof, along the surfaces of the hot plates 101a to 101c with the arrows in FIG. As shown, it is pivotable. Further, the transport claw 105 has a tip portion. In A recess 106 is provided, and the corner of the substrate matches the recess 106. A pair of movable frames 104 are provided on both sides of the hot plates 101a to 101c and the conveyors 102 and 103, and are movable along the substrate transport direction. A plurality of conveying claws 105 are provided on the upper surfaces of the pair of movable frames 104. Two conveyance claws 105 along the substrate conveyance direction and two opposite to each other across the hot plates 101a to 101c and the conveyors 102 and 103 constitute a conveyance nail group 105a to 105d. Each of the transport claws 105a to 105d transports the substrate while supporting the four corners of the substrate.
[0034]
Control means 120 is connected to these hot plates 101a to 101c, conveyors 102 and 103, movable frame 104, conveying claw 105, and pushers 127 and 109a to c and 128, as shown in FIG. The control means 120 includes a microcomputer for controlling these operations, a memory for storing control conditions, and the like. Connected to the control means 120 is a substrate detection device 150 for detecting the distance from the substrates on the hot plates 101a to 101c.
[0035]
[Substrate detector]
The substrate detection device 150 includes a sensor 151 that detects the distance between the substrate and the surface of the hot plates 101a to 101c, the presence / absence and state of the substrate on the hot plates 101a to 101c based on the output of the sensor 151, and whether or not the substrate is transported. And an evaluation means for evaluating the status of the corresponding hot plate. One sensor 151 is embedded in each of the hot plates 101a to 101c. As shown in FIG. 4, the evaluation unit 152 includes a comparison unit 153 and a calculation unit 154. The comparison unit 153 includes a first comparison unit 153a and a second comparison unit 153b, and threshold values x1 and x2 are set for each. The first comparison means 153a compares the output of the sensor 151 with the threshold value x1, and outputs an ON or OFF signal. The second comparison unit 153b compares the output of the sensor 151 with the threshold value x2, and outputs an ON or OFF signal. The computing means 154 evaluates the situation such as the presence or absence of the substrate using the ON or OFF signals from the first comparison means 153a and the second comparison means 153b.
[0036]
A substrate detection algorithm in the substrate detection apparatus 150 will be described with reference to FIGS. First, the substrate detection algorithm when the substrate warpage is large will be described. Next, it will be shown that the substrate can be detected using the substrate detection apparatus 150 of the present embodiment even when there is no substrate warpage.
[0037]
FIG. 5 is a schematic cross-sectional view of a substrate with a large warp and a hot plate 101. Here, in order to explain the influence of the warpage, the warpage of the substrate is shown with extreme emphasis. FIG. 5A shows a state where the substrate is placed on the hot plate 101, and FIG. 5B shows a state where the substrate is lifted by the pusher 109. Here, x1 and x2 are defined as follows. x1 is a state in which the substrate is warped by the heat treatment when the substrate is placed on the hot plate 101, and the substrate and the sensor when the warpage reaches the maximum amount that can occur depending on the process conditions to be treated. 151 is the maximum distance. x2 is the minimum value of the distance between the substrate and the sensor 151 when the substrate is lifted by the pusher 109, and this is caused by the deflection of the lifted substrate due to its own weight or heat treatment, and remains until lifted. This value includes the effects of warping. These x1 and x2 are experimentally determined according to the process conditions to be processed.
[0038]
First, a configuration and operation for evaluating the state of a hot plate such as the presence or absence of a substrate in the case where processing is performed under process conditions in which the substrate is warped by heat treatment will be described. Here, a case will be described where numerical values experimentally determined for x1 and x2 are x2 <x1. In this case, the first comparison unit 153a and the second comparison unit 153b are configured as follows using x1 as the threshold value of the first comparison unit 153a and x2 as the threshold value of the second comparison unit 153b.
[0039]
That is, the first comparing means 153a adjusts so that an ON signal is output when the distance x between the substrate and the sensor 151 is less than or equal to x1, and an OFF signal is output when the distance x is greater than x1. The second comparison means 153b adjusts so that an OFF signal is output when the distance x between the substrate and the sensor 151 is x2 or more, and an ON signal is output when the distance x is less than x2. These setting relationships are shown in FIG. 6. Here, the output of the comparison means 153 when the substrate is placed on the hot plate 101 (a) and when the substrate is lifted by the pusher 109 is shown. . However, since the first comparison unit 153a outputs an OFF signal when the distance x is larger than x1, it is necessary to adjust the sensitivity of the sensor so as not to detect the cover attached to the hot plates 101a to 101c.
[0040]
In order to determine that the “substrate is correctly placed” when the substrate is placed on the hot plate 101, the distance x must be less than or equal to x1. When the substrate warpage is relatively large, the distance x is less than x1 and less than x2. Up Thus, the output of the first comparison means 153a is ON and the output of the second comparison means 153b is OFF (i). When the substrate warpage is relatively small, the distance x is smaller than x1 and smaller than x2, the output of the first comparison means 153a is ON, and the output of the second output means 153b is ON (ii). Therefore, when the substrate is placed on the hot plate 101, it may be determined that “the substrate is correctly placed” in the case of i and ii.
[0041]
On the other hand, when the substrate is lifted by the pusher 109, the distance x must be greater than or equal to x2 in order to determine that the substrate has been lifted correctly. Further, when the substrate is lifted by the pusher 109, the warp due to heat becomes small, so that the distance x does not exceed x1. Therefore, in this case, the distance x is equal to or less than x1 and equal to or greater than x2, and the first comparison unit 153a outputs ON and the second comparison unit 153b outputs OFF (iii).
[0042]
In the above i and iii, the outputs of the first comparing means 153a and the second comparing means 153b are the same, but by obtaining the control state of the raising / lowering of the pusher 109 from the control means 120, the cases of i and iii And can be distinguished. When it is received from the control means 120 that the substrate is placed on the hot plate 101 (that is, when the pusher 109 is lowered), when the first comparison means 153a is ON and the second comparison means 153b is OFF , “Determine that the substrate is correctly placed”. On the other hand, when it is received from the control means 120 that the substrate has been lifted by the pusher 109, if the first comparison means 153a is ON and the second comparison means 153b is OFF, “the substrate has been lifted correctly”. to decide.
[0043]
By using the outputs of the first comparison unit 153a and the second comparison unit 153b set as described above, and obtaining and referring to the control state information of the pusher 109 from the control unit 120, the control calculation unit 154 obtains the corresponding hot The status of the plate can be evaluated. The contents of the situation evaluation by the computing means 154 and the control operation of the apparatus according to it are as follows.
[0044]
(A) When the pusher 109 is controlled to be lowered to place the substrate on the hot plate
(A-1) When the first comparison means 153a is ON and the second comparison means 153b is ON
Since this output shows consistently that the distance between the substrate and the sensor 151 is less than x2, “the substrate is normally placed on the hot plate” and “there is no or little thermal warping of the substrate”. State. In this case, the control unit 120 continues the hot plate process as it is.
[0045]
(A-2) When the first comparison means 153a is ON and the second comparison means 153b is OFF
This output shows that the distance between the substrate and the sensor 151 is not less than x2 and not more than x1, so that “the substrate is normally placed on the hot plate” and “the thermal warp of the substrate is large. Is the state. Also in this case, since the substrate is not damaged or the conveyance is not failed, the control unit 120 continues the processing on the hot plate as it is.
[0046]
(A-3) When the first comparison means 153a is OFF and the second comparison means 153b is ON
In this case, the output of the first comparison unit 153a and the output of the second comparison unit 153b are contradictory, and a threshold adjustment error of the first comparison unit 153a and the second comparison unit 153b is considered. In this case, the control means 120 receives the evaluation result, stops the apparatus, and outputs an alarm to the operator.
[0047]
(A-4) When the first comparison means 153a is OFF and the second comparison means 153b is OFF
Since this output indicates that the substrate is not placed on the hot plate, it is considered that the substrate has been damaged or has failed to be transported. On the other hand, the first comparison means 153a and the second comparison means A threshold adjustment error of 153b is conceivable. In any case, in this case, the control unit 120 receives the evaluation result, stops the apparatus, and outputs an alarm to the operator.
[0048]
(B) When controlling the pusher 109 to lift the substrate from the hot plate
(B-1) When the first comparison means 153a is ON and the second comparison means 153b is OFF
This output shows that the distance between the substrate and the sensor 151 is not less than x2 and not more than x1, without contradiction. From the definition of the distance x2, OFF of the second comparison means 153b indicates that the substrate is normally lifted up to a distance x2 or more. In this case, the control unit 120 continues the transport operation as it is.
[0049]
(B-2) When the first comparison means 153a is ON and the second comparison means 153b is ON
This output indicates that the distance between the substrate and the sensor 151 is less than x2. This is a state in which the distance between the substrate and the hot plate is short. For example, when the pusher 109 is lifted, the substrate is damaged by piercing the substrate or the like, or the first comparison unit 153a or the second comparison unit 153b. The threshold adjustment error may be considered. In this case, the control means 120 receives the evaluation result, stops the apparatus, and outputs an alarm to the operator.
[0050]
(B-3) When the first comparison means 153a is OFF and the second comparison means 153b is ON
In this case, the output of the first comparison unit 153a and the output of the second comparison unit 153b are contradictory, and a threshold adjustment error of the first comparison unit 153a and the second comparison unit 153b is considered. In this case, the control means 120 receives the evaluation result, stops the apparatus, and outputs an alarm to the operator.
[0051]
(B-4) When the first comparison means 153a is OFF and the second comparison means 153b is OFF
Although this output indicates that there is no substrate on the hot plate, a threshold adjustment error of the first comparison unit 153a is considered. In this case, the control means 120 receives the evaluation result, stops the apparatus, and outputs an alarm to the operator.
[0052]
FIG. 7 shows the output of the first comparison means 153a and the second comparison means 153b, the situation evaluation, and the algorithm of the apparatus operation.
[0053]
In both cases (a-2) and (a-3) of FIG. 7, it is determined that “the substrate is normally placed”, but the degree of warpage of the substrate is determined based on the output of the second comparison means 153b. can do. That is, if the output of the second comparison means 153b is ON as in (a-2), it can be determined that the distance x between the substrate and the mounting table is smaller than x2 and the warpage of the substrate is also small. On the other hand, if the output of the second comparison means 153b is OFF as in (a-3), it can be determined that the distance x between the substrate and the mounting table is greater than x2 and the substrate is warped.
[0054]
The following control can be performed using this result. That is, in the heating unit, the temperature of the hot plate 101 can be controlled so as to reduce the warpage of the substrate. In addition, the degree of warpage of the substrate can be reported to an external host computer, which can be used to create a recipe on the host computer. Also, by evaluating the warpage of the substrate, the relationship with defects due to thermal distortion that occurs on the substrate, and the amount of warpage due to the substrate material The I can grasp it. In addition, the warpage of the substrate can be reported to the downstream apparatus, which can be used for selecting a chemical solution and adjusting the liquid temperature.
[0055]
Also, in this device, when resetting the device and returning to the origin, or when starting the entire line that was stopped, is the substrate used in the previous process left on the hot plate 101 and left unattended? In order to confirm this, it is desirable to provide a step of confirming the presence or absence of the substrate. Specifically, in this embodiment, at such times, all the pushers 109a to 109c are once lowered. If the outputs of the first comparison unit 153a and the second comparison unit 153b are both OFF for all the hot plates 101, the evaluation unit 152 and the control unit 120 determine that there is no residual substrate, and Continue driving. If there is a hot plate 101 for which the output of either the first comparison means 153a or the second comparison means 153b is ON, the evaluation means 152 and the control means 120 determine that there is a residual substrate and stop the apparatus, Give an alarm to check the board.
[0056]
When the residual substrate is found and removed, the operator can continue the operation of the apparatus by performing the same confirmation process again. If there is no residual substrate even if it is confirmed, an abnormal setting such as a threshold adjustment error of the first comparison unit 153a or the second comparison unit 153b is considered, so a solution such as optimal adjustment is taken, The control means 120 does not resume the operation of the apparatus until the same confirmation process is performed again. It should be noted that such a residual substrate checking step is not limited to when the apparatus is returned to the origin or started, but can be configured to be performed immediately before receiving the substrate from the upstream apparatus during the operation of the apparatus.
[0057]
Moreover, it is preferable in the following points if the confirmation process of the presence or absence of a board | substrate as mentioned above is provided. That is, in this type of device, if the occurrence of an alarm frequently occurs, it is troublesome for the operator of the device. For example, the output of the first comparison means 153a is always an ON signal and the output of the second comparison means 153b so that no alarm is generated. It is conceivable that an erroneous driving operation is performed such as setting each threshold value so that the signal is always an OFF signal, or short-circuiting or opening the signal line to the comparison means. If the apparatus is operated in such a state, the alarm may not be issued even if the alarm must be issued, so that the substrate processing may not be performed normally. However, if the above-described substrate presence / absence confirmation process is executed, an alarm is issued before the operation of the apparatus is started if an attempt is made to operate with such an incorrect threshold setting or incorrect signal line wiring. It is possible to prevent an operator's erroneous driving operation.
[0058]
In order to simplify the sensitivity adjustment work of the sensor 151, that is, the work of setting the threshold values for the first comparison means 153a and the second comparison means 153b, x1, x2 for the first comparison means 153a and the second comparison means 153b. The relationship may be fixed so that either the first comparison unit 153a or the second comparison unit 153b adopts x1 as the threshold value and the other uses x2 as the threshold value. In this case, the algorithm may be changed so that (a-3) and (b-3) are determined as normal operations and the processing operation is continued. In this case, all cases (a-1), (a-2), (a-3), (b-1), and (b-3) are determined to be normal operations. Thus, there is no need to consider the magnitude relationship between x1 and x2 as will be described later, and the same detection and determination algorithm can be applied regardless of whether the amount of warpage of the substrate is large or small, and switching of the algorithm becomes unnecessary.
[0059]
Moreover, the algorithm of FIG. 7 can also be simplified and used as a modification of the said embodiment. That is, in this modification, when a signal indicating that the substrate is placed on the hot plate 101 is received in FIG. 7, the output of either the first comparison unit 153a or the second comparison unit 153b is ON. If it is determined that “the substrate is correctly placed” and a signal indicating that the substrate is lifted by the pusher 109 is received, either the first comparison unit 153a or the second comparison unit 153b is OFF. If there is, it is determined that “the substrate is lifted correctly”. In this case, the alarm is not issued in the cases of (a-3), (b-3), and (b-4). However, in these cases, the thresholds x1 and x2 are misadjusted. If there are no minor adjustment errors, a simplified algorithm is sufficient.
[0060]
The amount of warpage of the substrate varies depending on process conditions to be processed, such as the substrate material, the temperature setting of the heating unit, and the temperature setting of the cooling unit. The process condition to be processed may be such that the substrate warpage is small and x1 <x2. When the experimentally determined values of x1 and x2 are x1 <x2, the respective values are set as threshold values, and if the following algorithm shown in FIG. Device hardware similar to the larger case Ye It can be used as it is. That is, when it is received from the control means 120 that the substrate is placed on the hot plate 101, only when the output of the first comparison means 153a and the output of the second comparison means 153b are both ON, the “substrate is placed normally. Otherwise, it is judged abnormal and an alarm is output. On the other hand, when it is received from the control means 120 that the substrate is lifted by the pusher 109, it is determined that “the substrate is lifted normally” only when the outputs of the first comparison means 153a are both OFF. Determines that it is abnormal and outputs an alarm. When the algorithm is changed in this way, the same hardware can be used even when x1 <x2.
[0061]
Note that x1 = x2 may be considered, but in this case, the status of the corresponding hot plate can be evaluated as follows.
[0062]
(E) When the pusher 109 is controlled to be lowered to place the substrate on the hot plate
(E-1) When the first comparison means 153a is ON and the second comparison means 153b is ON
It is determined that the substrate has been successfully placed on the hot plate.
[0063]
(E-2) When the first comparison means 153a is ON and the second comparison means 153b is OFF
In this case, it may occur due to a slight adjustment difference in the threshold value, so that it is determined that it has been placed normally.
[0064]
(E-3) When the first comparison means 153a is OFF and the second comparison means 153b is ON
In this case as well as (e-3), it can be caused by a slight adjustment difference of the threshold value, so that it is determined that it has been placed normally.
[0065]
(E-4) When the first comparison means 153a is OFF and the second comparison means 153b is OFF
In this case, it is determined as abnormal, the apparatus is stopped, and an alarm is issued to the operator.
[0066]
(F) When controlling to raise the pusher 109 to lift the substrate from the hot plate
(F-1) When the first comparison means 153a is OFF and the second comparison means 153b is OFF
In this case, it is determined that the substrate has been lifted normally.
[0067]
(F-2) When the first comparison means 153a is ON and the second comparison means 153b is ON
In this case, it is determined as abnormal, the apparatus is stopped, and an alarm is issued to the operator.
[0068]
(F-3) When the first comparison means 153a is ON and the second comparison means 153b is OFF
In this case, since it may occur due to a slight adjustment difference in the threshold value, it is determined that it has been lifted normally.
[0069]
(F-4) When the first comparison means 153a is OFF and the second comparison means 153b is ON
In this case as well as (f-3), it can be caused by a slight adjustment difference of the threshold value, so that it is determined that it has been lifted normally.
[0070]
In the above embodiment, the sensor 151 may be arranged on the hot plates 101a to 101c. In addition, the sensor 151 may be an optical means, or a means using ultrasonic waves, magnetism, capacitance, or the like. In the present embodiment, one sensor is provided for each of the hot plates 101a to 101c and two systems of outputs are output therefrom, but a plurality of sensors may be used to provide separate sensors for each comparison means. Good. In this embodiment, the sensor 151 is embedded in the surface of the hot plates 101a to 101c. However, the present invention is not limited to this. For example, the surface of the hot plates 101a to 101c is viewed from above the hot plates 101a to 101c. It may be provided and indirectly measure the distance between the surface of the hot plates 101a to 101c and the substrate by measuring the height of the substrate.
[0071]
[Operation]
Processing of the substrate in the heating unit including the substrate detection device 150 as described above will be described with reference to FIGS. When the substrate W1 is transported from the upstream processing unit to the conveyor 102, the pushers 127, 109a to c, 128 are simultaneously raised, and the pusher 127 lifts the substrate W1. Each of the transport claws 105 simultaneously rotates in the direction of the arrow in FIG. 2, and the concave portions 106 at the tip of the transport claws 105 are aligned with the four corners of the substrate W1 to hold the substrate W1. After the substrate W1 is held by the transport claw group 105a, the pushers 127, 109a to c, 128 are lowered, the movable frame 104 moves in the transport direction, and the transport claw group 105a is positioned at both ends of the hot plate 101a. It moves and the substrate W1 is transported to the upper side of the hot plate 101a. Here, the pushers 127, 109a to c, 128 are raised again, and the pushers 109a support the four corners of the substrate W1. Next, each of the transport claws 105 rotates to return to the original position and leaves the substrate W1. Thereafter, the pushers 127, 109a to c, 128 are simultaneously lowered, and the substrate W1 is placed on the hot plate 101a. Then, the movable frame 104 also moves to the opposite side to the transport direction and returns to the original position. When the substrate detection device 150 determines that “substrate is normally placed” on the hot plate 101a, the substrate W1 starts to be heated on the hot plate 101a. During this time, the next substrate W2 is carried into the conveyor 102.
[0072]
When the heat treatment in the hot plate 101a is completed, the pushers 127, 109a to c, 128 are simultaneously lifted to lift the substrates W1 and W2. Here, when the substrate detection device 150 determines that the substrate is normally lifted by the hot plate 101a, the transport claws 105 are simultaneously rotated to hold the substrates W1 and W2, and then the pushers 127, 109a to c, 128 are moved. Descend simultaneously. With the substrates W1 and W2 held by the transfer claws 105, the movable frame 104 moves in the transfer direction, the substrate W1 moves above the hot plate 101b, and the substrate W2 moves above the hot plate 101a. Next, the pushers 127, 109a to c, 128 are simultaneously lifted to hold the substrates W1, W2, and then the transport claws 105 are simultaneously rotated to return to the original positions. Next, the pushers 127, 109a to c, 128 are simultaneously lowered, and the substrate W1 is placed on the hot plate 101b and the substrate W2 is placed on the hot plate 101a. When it is determined that the substrate is normally placed on the hot plates 101a and 101b, a heat treatment is performed. During this time, the next substrate W3 is transferred to the conveyor 103.
[0073]
The above procedure is repeated, and the substrate is sequentially heated in the hot plates 101a to 101c.
[0074]
According to the substrate detection device 150 of the present embodiment, even when the substrate is warped, the state of the substrate can be reliably detected using the two threshold values x1 and x2. Thereby, a heating or cooling process can be performed in a state where the substrate is reliably placed on the plate. Further, since it is confirmed that the substrate has been lifted by the pusher 109 and the substrate is conveyed by the conveyance claw 105, the substrate can be reliably conveyed. Furthermore, an alarm can be issued when the threshold value of the comparison means is set incorrectly.
Further, according to the operation method of the present embodiment, even if an operator performs an incorrect operation, an alarm can be issued before the operation of the apparatus is started, and an erroneous operation can be prevented in advance.
[0075]
In the above-described embodiment, the heating unit having a configuration in which the substrate is sequentially fed between the plurality of hot plates and heated for a predetermined heating time over the plurality of hot plates has been described. For example, the present invention can be applied to a heating unit having a configuration in which a plurality of hot plates are provided in upper and lower stages, each hot plate is heated for a predetermined heating time, and each hot plate is operated in parallel. Moreover, although the said embodiment demonstrated taking the case of the hot plate which heat-processes a board | substrate, this invention is applicable to the cooling plate which cools a board | substrate, for example. In still other applications, the present invention can be applied to applications where the presence or absence of a substrate and its state are detected by a mounting table.
[0076]
【The invention's effect】
According to the present invention, even when the warpage of the substrate is large, it is possible to reliably detect the state of placement or lifting of the substrate using the two threshold values. Thereby, a heating or cooling process can be performed in a state where the substrate is reliably placed on the plate. In addition, since it is confirmed that the substrate is lifted by the transport means and transport to the next plate is started, the substrate can be transported reliably.
[0077]
According to another aspect of the present invention, since the degree of warpage of the substrate can be grasped, the temperature can be controlled to reduce the warpage of the substrate in the heating unit and the cooling unit based on the warp of the substrate. . In addition, the degree of warpage of the substrate can be reported to an external host computer, which can be used to create a recipe on the host computer. In addition, by evaluating the warpage of the substrate, it is possible to grasp a problem due to thermal distortion generated in the substrate and the amount of warpage due to the substrate material. In addition, the warpage of the substrate can be reported to the downstream apparatus, which can be used for selecting a chemical solution and adjusting the liquid temperature.
[Brief description of the drawings]
FIG. 1 is a plan view of a substrate processing apparatus.
FIG. 2 is a plan view of the heating unit.
FIG. 3 is a configuration block diagram of a heating unit.
FIG. 4 is a block diagram of a substrate detection device.
FIG. 5 is a diagram illustrating a distance between a substrate and a mounting table.
FIG. 6 shows the output from the comparison means.
FIG. 7 shows a substrate detection algorithm.
FIG. 8 shows a substrate detection algorithm (when warping is small).
FIG. 9 shows a substrate detection algorithm (when two threshold values are equal).
[Explanation of symbols]
1 Substrate processing equipment
2 Exposure machine
3 cassettes
10 Cleaning unit
20 Dewatering bake unit
30 Application unit
40 pre-baked units
50 I / F section
60 Development unit
70 Post bake unit
80 conveyor units
90 Indexer
90R indexer robot
101a-c hot plate
102, 103 conveyor
104 Movable frame
105 Transport claw
105a-d Transport claw group
106 recess
109a-c, 127, 128 pushers
120 Control means
151 sensor
152 Evaluation means
153 Comparison means
153a / b first / second comparison means
154 Calculation means

Claims (14)

A substrate detection device for detecting a state of a substrate placed on a placement table,
A sensor for detecting the presence height of the substrate at a specific position of the mounting table;
First comparison means for comparing the detection result of the sensor with a first threshold;
A second comparison means for comparing a detection result of the sensor with a second threshold different from the first threshold;
Evaluation means for evaluating the detection results of the first and second comparison means and determining the state of the substrate in the mounting table;
A substrate detection apparatus comprising: The evaluation means evaluates the detection results of the first and second detection means to determine the state of warping of the substrate;
The substrate detection apparatus according to claim 1. A substrate processing apparatus for performing predetermined processing on a substrate,
A mounting table on which the substrate can be mounted;
A substrate detection device for detecting the state of the substrate placed on the mounting table,
The substrate detection apparatus includes:
A sensor for detecting the presence height of the substrate at a specific position of the mounting table;
First comparison means for comparing the detection result of the sensor with a first threshold;
A second comparison means for comparing a detection result of the sensor with a second threshold different from the first threshold;
Evaluation means for evaluating the detection results of the first and second comparison means and determining the state of the substrate in the mounting table;
A substrate processing apparatus. The evaluation means evaluates the detection results of the first and second detection means to determine the state of warping of the substrate;
The substrate processing apparatus according to claim 3. Transport means movable to a first position for placing the substrate on the mounting table and a second position for lifting the substrate from the mounting table;
And a control means for controlling the transport means,
The evaluation means refers to the control state of the transport means by the control means to determine the state of the substrate in the mounting table;
The substrate processing apparatus of Claim 3 or 4. The first threshold is:
The height of the substrate at the specific position when the maximum amount of warpage that can occur in the substrate placed on the mounting table is possible,
The second threshold is:
The substrate processing apparatus according to claim 5, wherein the substrate processing apparatus is a minimum value of a substrate existing height at the specific position when the transport unit is lifted by moving to the second position. The first threshold can be set higher than the second threshold.
The substrate processing apparatus according to claim 6. When the substrate processing apparatus is reset, the transfer means is moved to the first position, and the detection results of the first and second comparison means are evaluated;
The substrate processing apparatus according to claim 5. A substrate detection method for detecting a state of a substrate in a substrate processing apparatus that performs a predetermined process on a substrate mounted on a mounting table,
A first step of detecting whether a substrate is present within a first distance from the mounting table;
A second stage for detecting whether or not a substrate is present within a second distance shorter than the first distance from the mounting table;
A third step of evaluating the detection results in the first and second steps and determining the state of the substrate;
A substrate detection method for a substrate processing apparatus including: A fourth step of evaluating the detection results of the first and second steps and evaluating the warpage of the substrate;
The substrate detection method of the substrate processing apparatus according to claim 9. The substrate processing apparatus further includes a transport unit that is movable to a first position for placing the substrate on the mounting table and a second position for lifting the substrate from the mounting table, and a control unit that controls the transport unit.
In the third step, the state of the substrate in the mounting table is determined with reference to the control state of the transport unit by the control unit.
The substrate detection method of the substrate processing apparatus of Claim 9 or 10. The first distance is
The distance between the substrate and the mounting table at the specific position when the maximum amount of warpage that can occur in the substrate mounted on the mounting table is possible,
The second distance is
The substrate detection of the substrate processing apparatus according to claim 9, wherein the substrate detection apparatus has a minimum height of the substrate at the specific position and a distance of the mounting table when the transport means is lifted by moving to the second position. Method. The first distance is set longer than the second distance,
The substrate detection method of the substrate processing apparatus according to claim 12.   14. The method according to claim 11, further comprising a fifth step of moving the transport unit to the first position and evaluating the detection results of the first and second comparison units when the substrate processing apparatus is reset. A substrate detection method for a substrate processing apparatus.

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