JP5912455B2 - Substrate crack detection method and ion beam irradiation apparatus operating method based on the substrate crack detection method - Google Patents

Description

  The present invention is used for manufacturing a flat panel display (liquid crystal display, organic EL display, etc.) by irradiating a substrate with an ion beam and performing processes such as ion implantation and ion beam alignment processing on the substrate. The present invention relates to a technique for detecting a substrate crack in an ion beam irradiation apparatus.

  In recent years, the size of a substrate for a display has been increased with an increase in the size of the display. Such a large substrate is likely to be bent or warped during substrate transportation. For this reason, there is a possibility that the portion where the bending or warping occurs collides with the arm of the transfer robot, the wall surface of the vacuum container, or the like, and the substrate is cracked.

  As a technique for detecting such a substrate crack, a technique described in Patent Document 1 is used. In the technique disclosed in Patent Document 1, optical sensors are individually arranged below both ends and the center of a glass substrate conveyed in one direction, and the light output from each optical sensor is glass. The light is reflected by reflecting plates arranged opposite to each other across the place where the substrate passes, and is received by each optical sensor to generate a signal. And comparing the signal generated by the optical sensor provided below the central portion of the glass substrate and the signal generated by the optical sensor provided below both ends of the glass substrate, It is judged whether there is a crack in the substrate.

JP 2005-156539 A (paragraphs 0021 to 0022, FIGS. 1 to 3)

  In the case of a rectangular substrate such as a flat panel, substrate cracking is likely to occur at the edges. Therefore, in Patent Document 1, a method of detecting whether or not there is a substrate crack by using an optical sensor arranged below the both ends of the substrate is used. However, when the substrate size is increased, the substrate is warped and warped, and there is a concern that the substrate may be cracked at locations other than both ends of the substrate.

  When such a large substrate is used in the ion beam irradiation apparatus, the substrate surface is charged up (charged) by irradiating the substrate with the ion beam. If the ion beam has a positive charge, the substrate is positively charged up. In order to suppress this charge-up, electrons have been conventionally supplied to the substrate surface by a plasma flood gun or an electron source. However, when the substrate size becomes large, electrons are sufficiently supplied over the entire surface of the substrate. Depending on the location on the substrate surface, the charge-up associated with the irradiation of the ion beam concentrates and discharge occurs at that location. In the worst case, the substrate may be broken.

  In consideration of the above-mentioned concerns, it is conceivable to increase the number of photosensors disclosed in Patent Document 1 so that it is possible to detect substrate cracks occurring at locations other than both ends of the substrate. Increases the cost of the system related to substrate crack detection.

  Also, as the number of photosensors increases, the failure rate of the entire substrate crack detection system increases, so a special process to check whether each photosensor operates normally before substrate crack detection is performed However, in this case, the configuration related to substrate crack detection becomes complicated.

  In consideration of the above-described problems, the present invention provides a substrate crack detection method capable of detecting a substrate crack over a wide range using an inexpensive and simple configuration in an ion beam irradiation apparatus. With one purpose.

  Another object of the present invention is to provide a method of operating an ion beam irradiation apparatus based on the substrate crack detection method.

One of the substrate cracking detection methods according to the present invention includes a processing chamber in which a substrate to which an ion beam is irradiated is disposed, and one in the processing chamber that supports the substrate and faces the back surface of the substrate. A substrate support member having the above-described opening, and an irradiation region in which at least a part of the ion beam is irradiated onto the substrate by driving the substrate support member in a direction intersecting the ion beam, and the ion beam A substrate driving mechanism that transports the substrate to a non-irradiated region that is not irradiated on the substrate and performs ion beam irradiation processing on the entire surface of the substrate, and a position on the downstream side of the substrate where the ion beam is irradiated And has a dimension substantially the same as or larger than the dimension of the substrate in a direction orthogonal to the traveling direction of the ion beam and the transport direction of the substrate. An ion beam irradiation apparatus having a beam current measuring instrument, while the substrate to the exposure area is conveyed, based on the measurement values of constantly measured beam current by the beam current measuring instrument, the substrate It is characterized by detecting the presence or absence of cracks.

  Usually, in ion beam irradiation devices such as ion implantation devices and ion beam alignment devices, the beam current of the ion beam is measured with a beam current measuring instrument when the device is started up so that the measurement result has a desired current amount and current density distribution. The parameters of the beam optical system (ion source, extraction electrode system, etc.) arranged in the beam path are adjusted. In the substrate crack detection method of the present invention, since the substrate crack detection is conventionally performed using the beam current measuring instrument provided in the ion beam irradiation apparatus, the apparatus standing before the substrate crack detection is performed. It is possible to confirm whether or not the beam current measuring instrument, which is a means for detecting a substrate crack, is operating normally during the adjustment. Therefore, a special configuration or process for confirming whether the means for detecting substrate cracking is operating normally is not required.

  In addition, the configuration used in the substrate crack detection method of the present invention is special for substrate crack detection because only the configuration of the beam current measuring instrument and the substrate support member conventionally used in the ion beam irradiation apparatus needs to be changed. The cost is low because no additional members are required. Furthermore, since the beam current measuring device is disposed at a position where the ion beam is irradiated and an opening is formed on the surface of the substrate support member facing the back surface of the substrate, a change from the conventional apparatus configuration can be easily performed. be able to. In addition, in the direction orthogonal to the ion beam traveling direction and the substrate transport direction, the beam current measuring device is substantially the same size as or larger than the substrate size. Substrate crack detection can be performed.

  Others of the substrate crack detection method according to the present invention are the regions in the irradiation region, except for the transition region where a part of the ion beam is irradiated on the substrate in the transport direction of the substrate, When the measured value of the beam current measured by the beam current measuring instrument exceeds a predetermined threshold, it is determined that the substrate is cracked.

  Measurement of the beam current measured by the beam current measuring instrument when there is no crack in the irradiation area, except for the transition area where a part of the ion beam is irradiated onto the substrate in the substrate transport direction. The value is a substantially constant value. For this reason, if a predetermined threshold value (constant value) is set and it is determined that there is a substrate crack when the measured value exceeds this value, it is possible to easily determine the substrate crack. Can do.

  Further, the beam current measuring device may be composed of one Faraday cup.

  By using a single Faraday cup, the configuration used for substrate crack detection can be simplified.

  On the other hand, the beam current measuring device may be composed of a plurality of Faraday cups.

  By using a plurality of Faraday cups, it is possible to specify the location where the substrate is cracked.

  One of the operation methods of the ion beam irradiation apparatus according to the present invention is to stop irradiation of the ion beam to the substrate when it is detected that the substrate is broken by the substrate crack detection method described above. It is a feature.

  By using the above operation method in combination with substrate crack detection, even if a member supporting the back surface of the substrate is exposed due to substrate cracking, the member is thermally deformed by being irradiated with an ion beam for a long time. Can be suppressed. In addition, when using a substrate support member having an insulating support pin that supports the back surface of the substrate, the irradiation of the ion beam to the substrate is stopped even when the support pin is exposed due to substrate cracking. The ion beam is not irradiated on the support pin for a long time. Thereby, it can be expected to reduce the adverse effect on the insulating properties of the support pins.

  In another operation method of the ion beam irradiation apparatus according to the present invention, after detecting that the substrate is broken by the substrate crack detection method described above, the irradiation of the ion beam to the substrate is stopped. The ion beam generation is stopped at the ion beam generation source.

  By using the above operation method in combination with substrate crack detection, the ion beam collides with the side wall of the vacuum vessel and the beam optical system (extraction electrode system, mass analysis magnet, etc.) arranged on the beam path. Sputtering that occurs can be prevented.

  Further, in the operation method of the ion beam irradiation apparatus described above, the substrate driving mechanism may transport the substrate while decelerating the substrate for a predetermined distance or a predetermined time after detecting that the substrate is cracked. desirable.

  By carrying the substrate while decelerating, the load on the substrate due to the sudden stop of the substrate support member can be reduced. This can be expected to prevent the substrate from falling off the substrate support member and the failure of the substrate drive mechanism.

  On the other hand, in the operation method of the ion beam irradiation apparatus described above, after the substrate driving mechanism detects that the substrate is cracked, the substrate is moved to a position where conveyance of the substrate is started at the time of ion beam irradiation processing. May be transported.

  By using the configuration described above, after cleaning the cracked substrate, it is not necessary to adjust the position of the transport system and return the substrate support member to the initial position immediately after performing ion beam irradiation processing on the new substrate. The next substrate can be conveyed to perform ion beam irradiation treatment.

  In the present invention, since a conventional method is used to detect a substrate crack using a beam current measuring instrument provided in an ion beam irradiation apparatus, it is detected at the time of start-up adjustment performed prior to the detection of a substrate crack. It is possible to confirm whether the beam current measuring instrument as the means is operating normally. Moreover, since it is only necessary to change the configuration of the beam current measuring instrument and the substrate support member conventionally used in the ion beam irradiation apparatus, the cost is low because no special additional member is required for substrate crack detection. That's it. Further, since the beam current measuring device is disposed at a position where the ion beam is irradiated and an opening is formed on the surface of the substrate support member facing the back surface of the substrate, the change from the conventional apparatus configuration can be easily performed. . In addition, in the direction perpendicular to the ion beam traveling direction and the substrate transport direction, the beam current measuring device is substantially the same size as or larger than the main surface size of the substrate. It is possible to detect substrate cracks over a wide range.

It is a top view showing an example of the ion beam irradiation apparatus concerning this invention. An example of the board | substrate support member and board | substrate drive mechanism of FIG. 1 is represented. (A) is a perspective view of a board | substrate support member, (B) is sectional drawing of a board | substrate drive mechanism. It is an example of the beam current measuring device described in FIG. (A) represents a beam current measuring instrument composed of one Faraday cup, and (B) represents a beam current measuring instrument composed of a plurality of Faraday cups. It is an example about board | substrate conveyance in the ion beam irradiation apparatus of FIG. (A) represents a state when the substrate is transported from the left side to the right side of the drawing, and (B) represents a change in the beam current value measured during the substrate transport described in (A). It is another example about board | substrate conveyance in the ion beam irradiation apparatus of FIG. (A) represents a state when the substrate is transported from the right side to the left side of the drawing, and (B) represents a change in the beam current value measured during the substrate transportation described in (A). In the example shown in FIG. 4, an example in which the substrate is cracked is shown. (A) shows a state when a partially broken substrate is conveyed from the left side to the right side of the drawing, and (B) shows a change in the beam current value measured during substrate conveyance described in (A). Represent. The example shown in FIG. 4 represents an example in which the beam current measuring device is composed of a plurality of Faraday cups. (A) shows the state when the substrate is transferred from the left side to the right side of the drawing, and (B) shows the change in the total beam current value measured for all Faraday cups during the substrate transfer described in (A). Represent. (C) represents the change of the beam current value measured by one Faraday cup. The measurement result of the beam current measured by each Faraday cup shown in FIG. 7 is represented. In the example shown in FIG. 7, an example in which the dimension of the beam current measuring instrument is larger than the dimension of the substrate is shown. (A) represents a state when the substrate is transported from the left side to the right side of the drawing, and (B) represents a change in the beam current value measured during the substrate transport described in (A). FIG. 6 is a plan view illustrating a modification example of the substrate support member illustrated in FIG. 2. (A) is a substrate support member having one square-shaped opening, (B) is a substrate support member having two square-shaped openings, and (C) is a cross-section formed obliquely. It is the board | substrate support member made. It is sectional drawing showing an example of the ion source and extraction electrode system which are described in FIG.

  FIG. 1 shows an example of an ion beam irradiation apparatus according to the present invention. This type of ion beam irradiation apparatus is conventionally known as an ion implantation apparatus. The outline of the apparatus configuration will be described below.

  In the ion beam irradiation apparatus 1, plasma is generated by the ion source 2, and the extraction beam system 4 disposed adjacent to the ion source 2 extracts the ion beam 3 having desired energy from the plasma. Thereafter, the ion beam 3 extracted by the extraction electrode system 4 enters the mass analysis magnet 5, where mass analysis is performed.

  The ion beam 3 extracted by the extraction electrode system 4 includes various ion species. Some ion beam irradiation apparatuses perform an ion beam irradiation process by irradiating the substrate 8 only with desired ion species. In this example, such an apparatus is assumed, and the mass analysis is performed by the illustrated mass analysis magnet 5 and the analysis slit 6 disposed on the downstream side (the traveling direction side of the ion beam 3). Only the ion beam 3 including the ion species is configured to pass through the analysis slit 6. If the energy of the ion beam is the same, there is a difference in the deflection amount of the ion beam including each ion species passing through the mass analysis magnet 5 depending on the mass of the ion species. Using this difference in deflection amount, mass analysis is performed by appropriately changing the magnetic field generated in the mass analysis magnet 5 so that the ion beam containing the desired ion species passes through the analysis slit 6. .

  The ion beam 3 that has passed through the analysis slit 6 is introduced into the processing chamber 7. In the processing chamber 7, the substrate support member 9 that supports the substrate 8 is driven by a substrate driving mechanism 14 described later, whereby the substrate 8 is reciprocated and conveyed in the direction of the arrow shown in the drawing. By this conveyance, the ion beam 3 is irradiated onto the substrate 8 and the ion beam irradiation processing to the substrate 8 is performed. Examples of the substrate 8 include a substrate such as a glass substrate or a silicon wafer on which a semiconductor element is formed. In this embodiment, a rectangular substrate is taken as an example, but the shape of the substrate may be circular.

  A substrate transfer chamber (not shown) is connected to the processing chamber 7 via a valve 10, and the substrate 8 is carried in and out between the processing chamber 7 and the substrate transfer chamber. The processing chamber 7 is provided with a beam current measuring device 11 at a position downstream of the substrate 8 (on the traveling direction side of the ion beam 3) and irradiated with the ion beam 3.

  The ion beam irradiation apparatus 1 has a control device 12. When the ion beam 3 is irradiated to the beam current measuring device 11, the beam current measuring device 11 measures the beam current of the ion beam 3, and the measurement result is transmitted as a signal S1 to the control device 12 through an electric circuit (not shown). Is done. The control device 12 that has received the signal S1 outputs control signals S2 to S4 based on the signal. Based on these control signals S <b> 2 to S <b> 4, operation parameters of the ion source 2, extraction electrode system 4, and mass analysis magnet 5 are adjusted.

  An example of the substrate support member 9 shown in FIG. 1 is depicted in FIG. In this example, the substrate support member 9 is mainly composed of a frame 15 having a thickness in the traveling direction of the ion beam 3, and the substrate 8 is disposed inside the frame 15. Here, the illustration of the substrate 8 is omitted for simplification of the drawing.

  A permanent magnet 19 for maintaining the posture of the substrate support member 9 is provided above the frame body 15. A slider 20 for driving the substrate support member 9 by a substrate driving mechanism 14 described later is attached below the frame 15.

  A plurality of openings 18 (shown hatched portions) and a substantially well-shaped crossing portion 16 are formed on the opposite surface of the frame 15 to the substrate back surface (the surface on the back side of the surface irradiated with the ion beam). Has been. A plurality of support pins 17 are provided on the crossing portion 16, and the back surface of the substrate 8 (not shown) is supported by the support pins 17.

  In this invention, if the opening part 18 is formed in the frame 15 which comprises the board | substrate support member 9, it will not be restricted to the structure of the board | substrate support member 9 shown here. For example, two frames that sandwich the substrate 8 from the front and back are prepared, and the substrate 8 may be supported from both sides. With such a configuration, it can be expected that the substrate 8 is prevented from falling off from the substrate support member 9. Further, when the substrate is transported, the substrate 8 may collide with the inner side surface of the frame body 15 and an impact may be given to the substrate 8, so a shock absorbing damper is attached along the inner side surface of the frame body 15. You may make it leave.

  FIG. 2B illustrates an example of the substrate driving mechanism 14. Two permanent magnets 24 for holding the posture of the substrate support member 9 are supported on the ceiling of the processing chamber 7, and the permanent magnets attached above the substrate support member 9 between the permanent magnets 24. 19 is arranged. The opposing surfaces of the permanent magnets are configured to have the same polarity, and the posture of the substrate holding member 9 that supports the substrate 8 is maintained by the repulsive force acting between the permanent magnets. .

  The slider 20 attached below the frame 15 is an elongated round bar, and this is supported so as to be movable on a rotating member 21 disposed in the processing chamber 7. The rotating member 21 is locked to a substantially central portion of the support shaft 22. One end of the support shaft 22 is connected to a motor 23 disposed outside the processing chamber 7, and the other end of the support shaft 22 is The bearing 25 provided in the processing chamber 7 is rotatably supported. With this configuration, by rotating the motor 23, the rotating member 21 is rotated via the support shaft 22 connected to the motor 23, and the slider 20 can be moved to the back or front of the page. it can. A plurality of drive units each including the rotation member 21, the support shaft 22, the motor 23, and the bearing 25 are provided along the back or front of the page.

  An example of the beam current measuring instrument 11 shown in FIG. 1 is depicted in FIGS. 3 (A) and 3 (B). In FIG. 3A, a single Faraday cup 26 having a large measurement part (a hatched area in the figure) is depicted. Such a Faraday cup 26 may be used as the beam current measuring device 11.

  On the other hand, a multipoint Faraday 27 including a plurality of Faraday cups as shown in FIG. When such a multipoint Faraday 27 is used, when a substrate crack occurs, in addition to detecting the substrate crack, it is possible to specify which portion on the substrate is cracked.

  FIG. 4A shows the state when the substrate 8 is transported from the left side to the right side of the paper surface in the ion beam irradiation apparatus shown in FIG. 1, and the measurement of the beam current measured by the Faraday cup 26 at that time is shown. FIG. 4B shows how the value changes. Note that, when the dimension of the substrate support member 9 is larger than the dimension of the substrate 8 in the transport direction of the substrate 8, the measurement results of the beam current values described later will be slightly different, but here for the sake of simplicity of explanation. For convenience, the dimensions of both members are the same, or the dimensions of the substrate support member 9 are smaller than the dimensions of the substrate 8.

  In FIG. 4A, the traveling direction of the ion beam 3 is a direction from the front side to the back side, and the transport direction of the substrate 8 is a direction from the left side to the right side of the paper. And when the board | substrate 8 is conveyed, the Faraday cup 26 is arrange | positioned rather than the board | substrate 8 in the paper surface back side so that it may not interfere with the Faraday cup 26. FIG. These positional relationships can be easily understood with reference to FIG.

  When the substrate 8 is transported from the left side to the right side of the paper, the ion beam 3 is not irradiated onto the substrate 8 until the front end surface of the substrate 8 is irradiated to the ion beam 3 from the transport start position. Therefore, in this invention, the area | region between this is called the non-irradiation area | region. While the front end surface of the substrate 8 is located in this non-irradiation region, all the ion beams 3 irradiated to the substrate 8 during the ion beam irradiation processing are irradiated to the Faraday cup 26. For this reason, as shown in FIG. 4B, the measured value of the beam current is a constant value.

  When the front end surface of the substrate 8 is transferred beyond the non-irradiation region, a part of the ion beam 3 starts to be irradiated onto the substrate 8. At this time, as shown in FIG. 4B, the measured value of the beam current starts to gradually decrease. When the substrate 8 is further transported and the ion beam 3 is completely blocked in the transport direction of the substrate 8, the measured value of the beam current becomes zero as shown in FIG. Thereafter, when the substrate 8 is further transferred and the ion beam 3 blocked by the substrate 8 gradually leaks from the rear end surface of the substrate 8 toward the Faraday cup 26, the beam current is changed as shown in FIG. The measured value starts to increase gradually. The measured value of the beam current continues to increase until the substrate 8 is transported to a position where the ion beam 3 is not irradiated on the rear end surface of the substrate 8. As described above, the substrate 8 is irradiated with at least a part of the ion beam 3 after the ion beam 3 starts to be irradiated on the front end surface of the substrate 8 until the ion beam 3 is not irradiated on the rear end surface of the substrate 8. Has been. Therefore, in this invention, the area | region between this is called the irradiation area | region. Further, in the irradiation region, there is a region where only a part of the ion beam 3 is irradiated onto the substrate 8 in the transport direction of the substrate 8. In the present invention, this region is called a transition region.

  After reaching the position where the rear end surface of the substrate 8 is not irradiated with the ion beam 3, the transfer of the substrate 8 is completed (in this example, the position of the substrate 8 indicated by the broken line is the transfer end position). The substrate 8 is not irradiated with the ion beam 3. Therefore, in the present invention, the region between these is also called a non-irradiated region as in the previous example.

  As described above, as the substrate 8 is transported, the substrate 8 passes through the non-irradiation region, the irradiation region, and the non-irradiation region in order. In addition, the dimension of the ion beam 3 is larger than the dimension of the substrate 8 in a direction orthogonal to the transport direction of the substrate 8 and the traveling direction of the ion beam 3. Therefore, the ion beam irradiation process can be performed on the entire surface of the substrate 8 by transporting the substrate 8 as described in this example.

  Further, the Faraday cup 26 is configured so that the dimension of the Faraday cup 26 is substantially the same as or larger than the dimension of the substrate 8 in the direction orthogonal to the traveling direction of the ion beam 3 and the transport direction of the substrate 8. . By using such a Faraday cup 26, it becomes possible to measure and adjust the beam currents of all the ion beams 3 irradiated on the substrate 8. Further, by using the Faraday cup 26 having such dimensions, it is possible to detect a substrate crack over a wide range. In this example, the Faraday cup 26 is described as an example of the beam current measuring device 11, but the present invention is not limited thereto, and another one may be used. However, considering that substrate crack detection is performed over a wide range, it is desirable that the dimensional relationship with the substrate 8 is as described above.

  In FIG. 4A, the example in which the substrate 8 is transported from the left side to the right side of the paper has been described. In contrast, FIG. 5A shows an example in which the substrate 8 is transported from the right side to the left side of the drawing. In FIG. 5A, the substrate 8 and the Faraday are transported except that the transport direction of the substrate 8 is opposite to that in the example of FIG. The relationship between the arrangement and dimensions of the cup 26 and the like is the same as in the example of FIG. The measurement result of the beam current measured by the Faraday cup 26 shown in FIG. 5B is also the same as that shown in FIG. Therefore, the overlapping description is omitted here.

  As can be seen from FIGS. 5A and 5B, when the transport direction of the substrate 8 is different, the positions of the above-described regions with respect to the ion beam 3 and the Faraday cup 26 are different. However, the meaning of each area remains the same. While the substrate 8 having no cracks is conveyed in one direction, the non-irradiation region is a region where the ion beam 3 is not irradiated on the substrate 8, and the irradiation region is at least of the ion beam 3 on the substrate 8. A part of the ion beam 3 is irradiated on the substrate 8, and a part of the ion beam 3 is irradiated on the substrate 8. 4A and 5A, the respective regions are illustrated with reference to the position where the front end surface of the substrate 8 is transported. However, other locations (for example, the rear end surface) of the substrate 8 are illustrated. ) On the basis of the above, of course, there is a difference in the location where the above-described areas are illustrated. However, even in this case, the meaning of each area is not changed.

  FIG. 6A illustrates a state where the substrate 8 having a part of the crack is transferred in the example of FIG. In this figure, the positional relationship among the substrate 8, the ion beam 3, and the Faraday cup 26 is the same as the example of FIG. In addition, the meanings of the drawn regions are the same.

  As shown in FIG. 2A, the substrate support member 9 of the present invention has an opening 18 on the surface facing the back surface of the substrate 8. By adopting such a configuration, the ion beam 3 that is originally irradiated onto the substrate 8 is broken through the opening 18 that is opposed to the cracked portion of the substrate 8 because the substrate 8 is broken. The beam current measuring device 11 is irradiated. Therefore, as shown in FIG. 6B, the measured value of the beam current in the irradiation region is different from that shown in the example of FIG. Actually, it passes through the cracked location of the substrate 8 depending on the location where the substrate is cracked, the shape of the transition portion 16 provided with the support pins 17 supporting the back surface of the substrate 8 and the shape of the frame 15. It is conceivable that the ion beam 3 is partially blocked, but here, in order to simplify the explanation, the ion beam 3 passing through the place where the substrate 8 is cracked is all irradiated to the beam current measuring device 11. It will be explained as a thing.

  It is possible to detect that the substrate is cracked based on the difference in the measured values of the beam current. Specifically, an experiment is performed in advance on data relating to the increase or decrease of the beam current in the irradiation region when there is no substrate crack, or the beam current value at the time of starting adjustment of the substrate dimensions, substrate driving speed, and ion beam irradiation apparatus When performing the ion beam irradiation process, the calculation is performed based on the beam current amount of the ion beam irradiated onto the substrate. Then, while the substrate crack detection is performed, the reference data and the actual measurement value are compared. For example, when a deviation of 10% occurs from the reference data, the substrate is cracked. It can be considered to make a judgment. Moreover, what is necessary is just to carry out using the control apparatus 12 shown in FIG. Similarly, in another discrimination method related to substrate crack detection, which will be described later, the control device 12 may be used.

  Further, when attention is paid to a region other than the transition region in the irradiation region (in other words, a region where the substrate 8 completely blocks the ion beam 3 irradiated to the beam current measuring instrument 11 in the transport direction of the substrate 8), the substrate When there is no crack, the measured value of the beam current to be measured is a constant value (zero in the examples of FIGS. 4B and 5B). Therefore, if the measured value of the beam current measured when the substrate 8 is transported in this region exceeds a certain threshold value, it may be determined that the substrate is cracked. . In this case, as compared with the previous example, the processing related to the determination of the substrate cracking is simple. For example, when there is no substrate cracking, the beam current is not detected in the examples of FIGS. 4 and 5 when the substrate 8 is transported through this region. Therefore, when the substrate 8 is transported through this region, it is determined that the substrate is cracked when the beam current is detected (the measured value of the beam current is greater than zero). Also good. In addition, referring to the measurement result in FIG. 6B, it may be considered that the position of the transition region described on the left side of FIG. 6A is shifted, this description is not an error. These areas are areas set on the assumption that there is no substrate cracking.

  FIG. 7A shows an example in which a multipoint Faraday 27 is used in place of the Faraday cup 26 used in the example of FIG. In this case, the total measurement result depicted in FIG. 7B is the sum of the measurement results for each Faraday cup depicted in FIG. 7C. Is used to detect a substrate crack based on the method described in the above example.

  On the other hand, by comparing the measurement results of the individual Faraday cups, it is possible to identify the substrate crack detection and the location where the substrate is cracked. FIG. 8 shows the measurement results of the beam currents measured by the seven Faraday cups constituting the multipoint Faraday 27 described in FIG.

  The measurement results of the beam currents arranged in the vertical direction on the paper surface illustrated in FIG. 8 correspond to the individual Faraday cups illustrated in FIG. When the measurement results as depicted in FIG. 8 are obtained, the measurement results of the individual Faraday cups are compared. Then, in the measurement result with the Faraday cup located on the uppermost side of the paper, it can be seen that the measured value of the beam current at the center of the irradiation region is significantly different from the measurement results with other Faraday cups. Based on this comparison, it can be determined that a crack has occurred near the upper central portion of the substrate 8 corresponding to the upper Faraday cup.

  Also, rather than comparing the measurement results at each Faraday cup, prepare some reference data (threshold value, etc.) as in the method described above, and compare this with the measurement results at each Faraday cup. Then, the substrate crack may be detected.

  In order to detect the state of the ion beam 3 while the substrate 8 is irradiated with the ion beam 3, the dimension of the beam current measuring instrument 11 is set in the direction orthogonal to the traveling direction of the ion beam 3 and the transport direction of the substrate 8. The case where it is made larger than the dimension of the board | substrate 8 can be considered. In that case, as shown in FIG. 9, the measured value of the beam current in the region excluding the transition region in the irradiation region does not become zero. However, there is no change to the constant value, so in such a case, a threshold value that is slightly higher than that value is set as the reference value, and if it exceeds that value, the substrate will crack. You can judge that you are doing.

  The shape of the opening 18 formed in the substrate support member 9 is not limited to the shape shown in FIG. For example, the opening 18 illustrated in FIGS. 10A to 10C may be formed in the substrate support member 9. The larger the shape of the opening 18 is, the larger the substrate crack detection area is. However, as the shape of the opening 18 is larger, the support on the back surface of the substrate becomes insufficient. For this reason, the shape of the opening 18 may be appropriately determined in consideration of the size and rigidity of the substrate in consideration of the support of the back surface of the substrate and the detection range of the substrate crack.

  If irradiation of the ion beam 3 is continuously performed in a state where the substrate 8 is cracked, the member supporting the back surface of the substrate is exposed due to the substrate cracking, and the ion beam 3 is irradiated to the member for a long time. There is concern about deformation due to the heat of the ion beam. Further, when the substrate support member 9 including the insulating support pins 17 that support the back surface of the substrate is used, the support pins 17 are exposed due to the substrate cracking, and the ion beam 3 is irradiated on the support pins 17 for a long time. As a result, there is a concern that the insulating properties of the support pins 17 are adversely affected. Therefore, when it is detected that the substrate 8 is cracked, it is necessary to immediately stop the irradiation of the ion beam 3 to the substrate 8.

  In stopping the irradiation of the ion beam 3 onto the substrate 8, in the ion beam irradiation apparatus 1 shown in FIG. 1, the deflection amount of the ion beam 3 is changed by the mass analysis magnet 5, and the ion beam 3 is placed in the processing chamber 7. It is conceivable that the power source is not introduced, or various power sources provided in the ion source 1 and the extraction electrode system 4 are stopped so that the ion beam 3 is not extracted. In this case, as shown in FIG. 1, the control device 12 that has received the signal S <b> 1 representing the measurement result of the beam current measuring instrument 11 determines whether or not the substrate 8 is cracked. When it is determined that there is a control signal, the control signals S2 to S4 are generated to control the power source provided in each member.

  The ion beam irradiation apparatus 1 to which the present invention is applied is not limited to the configuration shown in FIG. If the ion beam irradiation apparatus 1 includes another means for stopping the introduction of the ion beam 3 into the processing chamber 7, it may be used. For example, a mechanical shutter is provided on the upstream side of the processing chamber 7 and is operated to prevent the introduction of the ion beam 3 into the processing chamber 7 and to irradiate the substrate 8 with the ion beam 3. You may make it stop.

  When it is detected that the substrate is cracked, it is necessary to open the processing chamber 7 to the atmosphere and remove the broken substrate. A valve capable of spatially separating the processing chamber 7 from the upstream beam path is provided so that maintenance work in the processing chamber 7 is not hindered by the valve. If the configuration is such that the introduction of the ion beam 3 into the processing chamber 7 can be blocked, the generation of the ion beam 3 may be continued. It is desirable to stop the generation itself.

  Further, when the deflection amount of the ion beam 3 by the mass analysis magnet 5 is changed and the ion beam 3 collides with an analysis tube provided in the mass analysis magnet 5 or the side wall of the vacuum vessel on the downstream side, the collided portion is There is a concern that the material may be sputtered and an early member replacement is required. From this, it is desirable to stop the generation of the ion beam 3 itself when the substrate crack is detected.

  Hereinafter, a method for stopping the generation of the ion beam 3 by the ion source 2 and the extraction electrode system 4 that are the generation source of the ion beam 3 will be described based on specific configurations of the ion source 2 and the extraction electrode system 4. .

  A configuration example of the ion source 2 and the extraction electrode system 4 is depicted in FIG. FIG. 11 is a cross-sectional view, and a plasma generation vessel 36, electrodes 30 to 33 constituting the extraction electrode system 4, and a permanent magnet 29 for generating a cusp magnetic field have lengths toward the front side of the paper. ing.

  This type of ion source is called a bucket-type ion source, and a plurality of permanent magnets 29 for generating a cusp magnetic field are arranged around the plasma generation vessel 36 constituting the ion source 2. A cusp magnetic field is generated in the plasma generation container 36 by the permanent magnet 29.

  A gas source 28 for introducing ionized gas is connected to the plasma generation vessel 36 via a flow rate controller (mass flow controller) (not shown). In addition, a plurality of filaments 34 are attached to one side surface via an insulator so that the tips protrude into the plasma generation container 36. A filament power supply VF is connected between the terminals of these filaments 34, and current is passed through the filaments 34 using the filament power supply VF, whereby the filaments 34 are heated and thermionic electrons are emitted. The thermoelectrons emitted from the filament 34 collide with the ionized gas supplied from the gas source 28, and the ionized gas is ionized to generate plasma 35. The thermoelectrons emitted from the plasma 35 and the filament 34 are confined in the plasma generation container 36 by the cusp magnetic field described above.

  The extraction electrode system 4 is composed of four electrodes 30 to 33. Each of the electrodes 30 to 33 is a flat plate electrode having a rectangular plane, and a large number of holes or slits for extracting an ion beam are formed on the surface thereof. Moreover, each electrode 30-33 is electrically attached independently with respect to the insulation flange which is not shown in figure. Each electrode will be briefly described. The acceleration electrode 30 disposed on the plasma generation container 36 side is an electrode for determining the energy of the ion beam 3 extracted from the plasma generation container 36, and the extraction electrode 31 generates a potential difference with the acceleration electrode 30. The electrode is used to extract the ion beam 3 from the plasma 35 by the action of an electric field. The suppression electrode 32 is an electrode used to suppress the inflow of electrons from the downstream side, and the ground electrode 33 is an electrode that is electrically grounded to fix the potential.

  The potentials of the electrodes 30 to 33 constituting the plasma generation container 36, the filament 34, and the extraction electrode system 4 are set using the illustrated power supplies V1 to V5. When it is detected that the substrate is cracked, the voltage applied to the acceleration electrode 30 and the extraction electrode 31 is made zero by turning off the power supply V2, the power supply V3, and the power supply V5 shown in the figure, and the ion beam 3 It is conceivable that the drawer of the machine is stopped. In this way, the generation of the ion beam 3 itself can be stopped. At this time, it is desirable to turn off other power sources at the same time. Also, it is better to stop the gas supply to the ion source 2 together.

  While stopping the irradiation of the ion beam 3 on the substrate 8, it is necessary to stop the conveyance of the substrate 8. However, when the conveyance of the substrate 8 is stopped, if the stop operation is started immediately after detecting that the substrate is cracked, the substrate driving mechanism 14 may be damaged due to a load due to inertial force. Further, when the substrate is cracked, the substrate 8 may not be sufficiently clamped with respect to the substrate support member 9, and in such a state, the substrate 8 may be detached from the substrate support member 9. Absent. Furthermore, since there is a possibility that a part of the broken substrate 8 enters the substrate driving mechanism 14, if the distance until the substrate 8 is stopped is too long, the substrate driving mechanism 14 may be broken. Therefore, in consideration of the above-mentioned concerns, it is desirable to stop the substrate 8 after it has been transported for a predetermined distance or for a predetermined time while decelerating the transport speed of the substrate 8.

  Further, when it is detected that the substrate is cracked, the broken substrate may be transported to a position where the substrate support member 9 is disposed at the start of the ion beam irradiation process in consideration of the transport cycle of the substrate 8. desired. If there is variation in the stop position of the substrate support member 9, a complicated control program for determining the stop position of the substrate support member 9 and returning it to the initial position in preparation for the next substrate transfer after cleaning of the broken substrate Is required. On the other hand, as described above, when there is no substrate cracking, the substrate 8 is cracked to a position at which the next substrate 8 starts to be transported (currently the same position as the position at which the transport of the substrate subjected to the ion beam irradiation process is started) If the substrate is transported, a new substrate can be transported smoothly after cleaning the cracked substrate, and the transport system control program can be simplified.

<Other variations>
The ion beam irradiation apparatus 1 in FIG. 1 is an apparatus having a mass analysis function, but may be an apparatus not having a mass analysis function. In this case, the illustrated mass analysis magnet 5 and analysis slit 6 are not necessary. Further, as an example of the ion source 2, a bucket type ion source is shown in FIG. 11, but the present invention is not limited to this, and a conventionally known burner type ion source or indirectly heated ion source may be used. Further, the number of electrodes constituting the extraction electrode system 4 does not have to be four, and may be one or more. In that case, the voltage applied to the electrode used for extraction of the ion beam 3 may be set to zero at the timing when it is detected that the substrate is broken.

  Further, in the above-described embodiment, it has been described that the substrate crack is determined by the control device 12, but instead, the operator of the ion beam irradiation device determines the substrate crack and operates various power sources. It may be left. In that case, for example, it is conceivable to prepare a monitor that can visually recognize the output from the beam current measuring instrument 11 and to output the measurement result of the beam current measuring instrument 11 to this monitor.

  Further, although an example in which the substrate 8 is reciprocally conveyed is described in FIG. 1, the substrate 8 may be conveyed in any one direction.

  In the embodiments described so far, an example in which a single substrate is transported has been described. However, the substrate crack detection method of the present invention can be applied even when a plurality of substrates are transported. For example, a large substrate support member that supports a plurality of substrates may be prepared, and the opening 18 as described in the above embodiments may be formed at a location where the back surface of each substrate is supported. For the configuration other than the substrate support member, the device configuration described so far may be used. In this case, it is better to use the multipoint Faraday 27 as the configuration of the beam current measuring instrument 11. This makes it possible to immediately know which substrate has cracked.

  In the embodiments described so far, as an example of the ion beam 3, a ribbon beam having a substantially rectangular cross section has been described as an example. However, instead of this, the cross section may have a square shape. Alternatively, it may be circular. Further, the size of the ion beam may be an ion beam having a size that covers the entire surface of the substrate irradiated with the ion beam. In addition, when such an ion beam is used, the substrate transport system may be configured to temporarily stop the substrate at a position where the ion beam is irradiated when the substrate is irradiated with the ion beam. In addition, a system in which a spot-like ion beam is scanned with a scanner to form an ion beam larger than the size of the substrate in one direction and the substrate is irradiated with the ion beam may be used.

  Of course, various improvements and modifications other than those described above may be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Ion beam irradiation apparatus 2 ... Ion source 3 ... Ion beam 4 ... Extraction electrode system 7 ... Processing chamber 8 ... Substrate 9 ... Substrate support member 11 ... Beam Current measuring instrument 14 ... substrate driving mechanism 18 ... opening

Claims (8)

A processing chamber in which a substrate irradiated with an ion beam is disposed;
A substrate support member that supports the substrate in the processing chamber and has one or more openings on a surface facing the back surface of the substrate;
By driving the substrate support member in a direction intersecting the ion beam, an irradiation region where at least a part of the ion beam is irradiated onto the substrate and a non-irradiation region where the ion beam is not irradiated onto the substrate are formed. A substrate driving mechanism for transporting the substrate and performing ion beam irradiation treatment on the entire surface of the substrate;
The ion beam is disposed at a position downstream of the substrate and irradiated with the ion beam, and is substantially the same as the size of the substrate in a direction orthogonal to the traveling direction of the ion beam and the transport direction of the substrate. Or an ion beam irradiation apparatus equipped with a beam current measuring instrument having a larger dimension,
A substrate crack detection method, comprising: detecting whether or not a substrate is cracked based on a measurement value of a beam current constantly measured by the beam current measuring instrument while the substrate is being transported into the irradiation region. .   The measured value of the beam current measured by the beam current measuring instrument in the region within the irradiation region, excluding the transition region where a part of the ion beam is irradiated on the substrate in the transport direction of the substrate. The substrate crack detection method according to claim 1, wherein the substrate is determined to be broken when the value exceeds a predetermined threshold. The substrate crack detection method according to claim 1, wherein the beam current measuring instrument is used for adjustment of the ion beam performed when the ion beam irradiation apparatus is started up.   3. The substrate crack detection method according to claim 1, wherein the beam current measuring device is configured by a plurality of Faraday cups.   5. The ion beam irradiation characterized by stopping irradiation of the ion beam to the substrate when it is detected by the substrate crack detection method according to claim 1, wherein the substrate is broken. How to operate the device.   6. The method of operating an ion beam irradiation apparatus according to claim 5, wherein when the irradiation of the substrate with the ion beam is stopped, the generation of the ion beam is stopped at the source of the ion beam.   The operation of the ion beam irradiation apparatus according to claim 5 or 6, wherein the substrate driving mechanism transports the substrate while decelerating the substrate for a predetermined distance or a predetermined time after detecting that the substrate is cracked. Method. 7. The substrate driving mechanism, after detecting that the substrate is broken, transports the substrate to a position where the transport of the substrate is started during the ion beam irradiation process. An operation method of the ion beam irradiation apparatus described.

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