Ingot V-notch evaluation device

Abstract

To provide a V-notch evaluation device for an ingot of a single crystal for a semiconductor device that makes it easy to inspect the measurement accuracy.SOLUTION: The ingot V-notch evaluation device includes a laser displacement meter 11 that includes a light-emitting unit and a light-receiving unit and that scans the shape of a V-notch, moving means for moving an ingot or the laser displacement meter 11 relative to the ingot in the longitudinal direction of the ingot, data processing means for processing V-notch shape data obtained by scanning of the laser displacement meter 11, and standard sample moving means 40 that holds a standard sample 30 with V-notches 32, 33, 34 formed for evaluation and can be moved to an inspection position where the V-notch shape of the standard sample 30 is measured and inspected by the laser displacement meter 11 and to a storage position where it does not interfere with the ingot being moved by the moving means.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an ingot V-notch evaluation device. [Background technology]

[0002] Conventionally, a V-notch has been formed at the edge of a silicon wafer as a mark indicating the crystal orientation. This V-notch is formed by grinding the outer periphery of a grown silicon single crystal ingot, forming a V-shaped groove in the longitudinal direction of the ingot using a grinding stone or the like, and then slicing the ingot to the thickness of the silicon wafer. If the grinding wheel is deteriorated or chipped, the V-notch in the silicon wafer cannot maintain its normal shape, and this can lead to wafer cracks originating from the V-notch during the subsequent wafer processing process.

[0003] For this reason, Patent Document 1 discloses an ingot V-notch evaluation device that can measure the entire shape of a V-notch formed in the longitudinal direction of an ingot and can make a high-precision pass / fail determination. This ingot V-notch evaluation device comprises an optical measurement means having a light-emitting unit and a light-receiving unit, which scans the shape of the V-notch, a moving means for moving the ingot and the optical measurement means relatively in the longitudinal direction of the ingot, and a data processing means for processing V-notch shape data obtained by scanning with the optical measurement means, and the data processing means comprises a shape data acquisition unit for acquiring V-notch shape data measured by the optical measurement means, an evaluation data generation unit for performing coordinate transformation on the acquired V-notch shape data and generating evaluation data for evaluating the V-notch shape, and a pass / fail judgment unit for judging the pass / fail of the V-notch shape based on the generated evaluation data. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7035923 Summary of the Invention [Problem to be solved by the invention]

[0005] In the V-notch evaluation device, if the measurement accuracy is reduced due to, for example, dust adhering to the light-receiving section, there is a possibility that a normal V-notch may be erroneously determined to be abnormal, or a V-notch with a defect may be erroneously determined to be normal. For this reason, in order to maintain and manage the measurement accuracy of the V-notch evaluation device, there is a demand for a device that can easily check the measurement accuracy of the V-notch evaluation device, for example, during a pre-work inspection. An object of the present invention is to provide a V-notch evaluation device for semiconductor single crystal ingots that can easily check measurement accuracy. [Means for solving the problem]

[0006] The present invention provides an ingot V-notch evaluation device for evaluating a V-notch formed in the longitudinal direction of a semiconductor single crystal ingot, comprising: an optical measurement means having a light-emitting unit and a light-receiving unit and scanning the shape of the V-notch; a moving means for moving the ingot or the optical measurement means relatively in the longitudinal direction of the ingot; a data processing means for processing V-notch shape data obtained by scanning with the optical measurement means; and a standard sample moving means for holding a standard sample on which a V-notch for inspection has been formed and which can be moved to an inspection position and a storage position, wherein the inspection position is a position where the V-notch shape of the standard sample can be measured by the optical measurement means, and the storage position is a position where it does not interfere with the ingot being moved by the moving means.

[0007] In the ingot V-notch evaluation device of the present invention, it is preferable that the standard sample has a plurality of V-notches formed therein.

[0008] In the ingot V-notch evaluation device of the present invention, the plurality of V-notches preferably include a V-notch for determining normality and a V-notch for determining abnormality.

[0009] In the ingot V-notch evaluation device of the present invention, the standard sample moving means is preferably configured to include a support and a rotating frame that is rotatably mounted on the support and can be moved to the inspection position and the storage position, and that holds the standard sample, and the rotating frame is preferably configured to be fixable to the support at both the inspection position and the storage position.

[0010] In the ingot V-notch evaluation device of the present invention, it is preferable that the standard sample moving means is configured to include a holding stage on which the standard sample is held, and a moving device that slides and moves the holding stage between the inspection position and the storage position.

[0011] In the ingot V-notch evaluation device of the present invention, it is preferable that the data processing means comprises a shape data acquisition unit that acquires V-notch shape data measured by the optical measurement means, an evaluation data generation unit that performs coordinate transformation on the acquired V-notch shape data and generates evaluation data for evaluating the V-notch shape, and a pass / fail judgment unit that judges the pass / fail of the V-notch shape based on the generated evaluation data. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing the structure of a semiconductor single crystal ingot processing device including a V-notch evaluation device according to one embodiment of the present invention. FIG. [Figure 2] FIG. 2 is a schematic diagram showing the arrangement of the V-notch evaluation device and processing device. [Figure 3] FIG. 2 is a schematic diagram showing the structure of an optical measurement means in the V-notch evaluation device. [Figure 4] FIG. 2 is a functional block diagram showing the structure of a data processing means in the V-notch evaluation device. [Figure 5] 10 is a graph showing shape data of a V-notch scanned by the optical measurement means. [Figure 6]10 is a graph showing evaluation data generated by an evaluation data generating unit in the V-notch evaluation device. [Figure 7] 1A and 1B are diagrams showing a standard sample placed in the V-notch evaluation device, where (A) is a top view and (B) is a side view. [Figure 8] FIG. 10 is a front view showing a state in which a standard sample moving means for holding a standard sample in the V-notch evaluation device has been moved to an inspection position. [Figure 9] FIG. 10 is a side view showing a state in which a standard sample moving means for holding a standard sample in the V-notch evaluation device has been moved to an inspection position. [Figure 10] FIG. 10 is a front view showing the standard sample moving means moved to a storage position. [Figure 11] FIG. 10 is a side view showing the standard sample moving means moved to a storage position. [Figure 12] 4 is a flowchart showing a V-notch processing method in the embodiment. [Figure 13] 4 is a flowchart showing a normal inspection method for the V-notch evaluation device in the embodiment. [Figure 14] 4 is a flowchart showing an abnormality inspection method for the V-notch evaluation device in the embodiment. [Figure 15] FIG. 10 is a diagram showing a modified example of a standard sample placed in the V-notch evaluation device. DETAILED DESCRIPTION OF THE INVENTION

[0013] FIG. 1 shows a V-notch evaluation device 1 according to an embodiment of the present invention. The V-notch evaluation method using the V-notch evaluation device 1 is carried out after grinding the outer periphery of a grown semiconductor single crystal ingot SI and completing the V-notch VN processing, before sending it to the next slicing process. A typical semiconductor single crystal is a silicon single crystal, and the V-notch evaluation device 1 of the present invention can be used to evaluate V-notches formed in silicon single crystal ingots SI. Furthermore, the V-notch evaluation device 1 of the present invention can also be used to evaluate V-notches formed in semiconductor single crystal ingots other than silicon single crystals, as long as they can be measured using the optical measurement means described below. 2, the grown semiconductor single crystal ingot SI is sent from the stocker 2 to the grinders 7A to 7D. The grinders 7A to 7D grind the outer periphery of the ingot SI and process a V-notch VN. The ingot SI that has been machined to have a V-notch VN is evaluated by a V-notch evaluation device 1. The V-notch evaluation device 1 is placed between the stocker 2 and the long length station 8, or between the stocker 2 and the grinders 7C and 7D. The long length station 8 is a place where the ingot SI sent from the stocker 2 is temporarily stored.

[0014] As shown in Figure 1, the delivery control of ingots SI from stocker 2 to grinders 7A to 7D and long length station 8 is performed by delivery workstation 3, and when the number of ingot SI is input into delivery workstation 3, the number is output to the carry-out device 4. The unloading device 4 unloads the ingot SI corresponding to the number input from the stocker 2, with the ingot SI placed on the holding frame 6, to the unloading yard. Based on a command from the operation system 5, the ingots SI are carried out from the carrying-out yard to the grinders 7A to 7D and the long length station 8.

[0015] The V-notch evaluation device 1 is placed on the unloading yard and evaluates the V-notch VN machined on the ingot SI unloaded to the unloading yard. The V-notch evaluation device 1 includes a laser displacement meter 11, a frame 12, an air blow mechanism 13, and a V-notch analysis computer 14. The laser displacement meter 11, which serves as the optical measurement means, includes a light-emitting unit 11A, a light-receiving unit 11B, and a measurement value output cable 11C, as shown in Fig. 3. Note that the optical measurement means is not limited to the laser displacement meter 11, and may be anything that can measure the V-notch VN optically in a non-contact manner.

[0016] Although not shown, the light emitting unit 11A is equipped with a laser oscillator and a cylindrical lens, and converts the laser light emitted from the laser oscillator into a band-shaped laser light (illustrated in Figure 3) that gradually widens with distance, and irradiates the V-notch VN. Although not shown, the light receiving unit 11B is equipped with a focusing lens and a CMOS sensor, and the reflected light of the laser light irradiated from the light emitting unit 11A onto the V-notch VN is focused by the focusing lens of the light receiving unit 11B and imaged by the CMOS sensor to measure the shape of the V-notch VN.

[0017] The measurement data of the V-notch VN measured by the light receiving unit 11B is output to the V-notch analysis computer 14 via the measurement value output cable 11C. The laser displacement meter 11 of this embodiment can measure the V-notch VN at 64 kHz. By scanning the ingot SI and the laser displacement meter 11 while moving them relative to each other at a predetermined speed, the shape of the V-notch VN formed along the longitudinal direction of the ingot SI can be measured multiple times over the entire length in a short period of time.

[0018] The frame 12 serving as a holding means is made of a metal material having an inverted L-shape in a side view. The base end of the frame 12 in the direction of unloading the ingot SI is buried in the unloading yard, and the tip end of the frame 12 in the direction of unloading faces the ingot SI while floating in the air. A laser displacement meter 11 is suspended from the underside of the tip end of the frame 12, and the laser displacement meter 11 can scan the V-notch VN along the longitudinal direction of the ingot SI while viewed from above the ingot SI. Scanning of the V-notch VN by the laser displacement meter 11 is performed in response to a command from the operation system 5. This scanning is performed by the V-notch evaluation device 1 attached to the grinders 7C and 7D when the ingot SI processed by the grinders 7C and 7D is transported to the stocker 2. Furthermore, the V-notch evaluation device 1 attached to the long length station 8 performs this scanning when the ingot SI processed by the grinders 7A and 7B is returned to the stocker 2 and then transported from the stocker 2 to the long length station 8. That is, in this embodiment, the mechanism for transporting the ingot SI between the stocker 2 and the long length station 8 and the mechanism for transporting the ingot SI between the stocker 2 and the grinders 7C, 7D function as the moving means. However, the moving means is not limited to this, and may be configured by other transport mechanisms such as a belt conveyor, and the laser displacement meter 11 may be the moving means that can move in the longitudinal direction of the ingot SI.

[0019] The air blow mechanism 13, which serves as a foreign matter removal means, is provided on the base end side of the laser displacement meter 11 in the carry-out direction and is attached to the underside of the frame 12. The air blow mechanism 13 blows an air current onto the V-notch VN at a width corresponding to the laser scanning width of the laser displacement meter 11. By blowing an air current upstream of the laser displacement meter 11, dust and moisture that has adhered to the V-notch VN during the preceding peripheral grinding and notch forming processes can be blown away, allowing the laser displacement meter 11 to scan the surface of the V-notch VN in a clean state.

[0020] As shown in FIG. 4, the V-notch analysis computer 14 serving as a data processing means takes in the measurement values ​​of the V-notch VN output from the measurement value output cable 11C of the laser displacement meter 11 and determines the processed shape of the V-notch VN. The V-notch analysis computer 14 is composed of a general-purpose computer equipped with a processing unit 15 and a storage device 16 such as an SD memory or a hard disk. The V-notch analysis computer 14 is equipped with a shape data acquisition unit 17, an evaluation data generation unit 18, a pass / fail judgment unit 19, and an evaluation result recording unit 20 provided in the storage device 16, all of which are executed on the processing unit 15.

[0021] The shape data acquisition unit 17 acquires the measurement values ​​(V-notch shape data) of the V-notch VN output from the laser displacement meter 11 via the measurement value output cable 11C. Specifically, as shown in FIG. 5, the shape data acquisition unit 17 acquires the horizontal length position (widthwise position of the V-notch VN) and vertical position (depthwise position of the V-notch VN) of the V-notch VN as measurement values. Since the laser displacement meter 11 moves relatively to acquire measurement values ​​over the entire length of the V-notch VN, the shape data acquisition unit 17 acquires the horizontal and vertical positions over the entire length of the V-notch VN as measurement values. The acquired measurement values ​​are output to the evaluation data generation unit 18.

[0022] The evaluation data generation unit 18 performs coordinate transformation on the measurement values ​​of the V-notch VN acquired by the shape data acquisition unit 17 into a form that can be judged by the pass / fail judgment unit 19. The evaluation data generation unit 18 performs coordinate transformation on the acquired measurement values ​​using an affine transformation matrix that performs enlargement, reduction, translation, rotation, and skew, to generate evaluation data. Specifically, as shown in Fig. 6, the evaluation data generation unit 18 first performs rotational movement so that the machined surface of the V-notch VN faces directly upward. Next, the evaluation data generation unit 18 performs translational movement so that the bottom of the machined surface of the V-notch VN becomes the origin, thereby generating evaluation data. The generated evaluation data is output to the pass / fail judgment unit 19.

[0023] In this embodiment, the coordinate transformation by the evaluation data generation unit 18 is performed using an affine transformation matrix, but the present invention is not limited to this. For example, when scanning by the laser displacement meter 11 is performed from diagonally above the V-notch VN, the scanning plane is deformed into a trapezoidal shape with depth, so coordinate transformation may be performed using a projective transformation matrix. As described above, the present invention aims to determine the quality of the V-notch shape of the final product, a semiconductor single crystal wafer, while it is still in the ingot state. Therefore, it is preferable that the evaluation data be coordinate-transformed so that the V-notch shape will be the same as the V-notch shape that will appear on the sliced ​​surface in the subsequent slicing step.

[0024] The quality determination unit 19 determines the quality of the V-notch VN formed in the ingot SI based on the evaluation data generated by the evaluation data generation unit 18. Specifically, the quality determination unit 19 determines the quality of the V-notch VN by comparing the depth dimension of the V-notch VN, the width dimension of the V-notch VN, the angle of the inclined surface of the V-notch VN, and the shape of the V-notch VN with preset evaluation reference values. Note that the quality determination unit 19 is not limited to determining the quality based on these four items, and may, for example, determine the quality by evaluating only the depth dimension of the V-notch VN.

[0025] The V-notch evaluation device 1 is provided with a standard sample 30 used in inspection work to maintain and manage measurement accuracy, and standard sample moving means 40 for moving this standard sample 30 to an inspection position and a storage position. As shown in Fig. 7, the standard sample 30 is a block-shaped piece material cut from an ingot SI, and three V-notches 32, 33, and 34 are machined on a circular arc surface 31, which is the outer peripheral surface of the ingot SI. In this embodiment, the three V-notches 32, 33, and 34 are machined to conform to the standard depth dimension of the V-notch VN, and the central V-notch 32 is a standard V-notch machined to the standard median value of the depth dimension of the V-notch VN. The V-notch 33 on the left side of Fig. 7 is a non-standard V-notch machined to the lower outlier of the depth dimension of the V-notch VN, and the V-notch 34 on the right side is a non-standard V-notch machined to the upper outlier of the depth dimension. The depth dimension of each V-notch 32, 33, 34 is set according to the product specifications; for example, the standard value of the depth dimension of V-notch VN is 1.3±0.1 mm, the depth dimension of V-notch 32 is 1.3 mm, which is the standard median value, the depth dimension of V-notch 33 is 1.1 mm, which is smaller than the lower limit of the standard value, and the depth dimension of V-notch 34 is 1.5 mm, which is larger than the upper limit of the standard value. The intervals between the V-notches 32, 33, and 34 are set so that multiple V-notches 32, 33, and 34 do not fall within the measurement range of the laser displacement meter 11. In the standard sample 30 of this embodiment, the V-notches 32, 33, and 34 are formed at intervals of 20 mm. The size of the standard sample 30 is, for example, 80 mm in width, 30 mm in depth, and 15 mm in height, which is the minimum size that allows three V-notches 32, 33, and 34 to be formed at regular intervals.

[0026] The standard sample 30 is adhesively fixed to a stainless steel base plate 35. Positioning screw holes 36, 37, and 38 are formed in the base plate 35 in accordance with the positions of the V-notches 32, 33, and 34. Therefore, the screw holes 36, 37, and 38 are also formed at intervals of 20 mm, the same as the V-notches 32, 33, and 34.

[0027] As shown in FIGS. 8 to 11, the standard sample moving means 40 is configured to include a pair of support columns 41 fixed to the frame 12, and a rotating frame 45 attached to the support columns 41 so as to be rotatable. The support 41 includes a square cylindrical support body 411, a bracket 412 fixed to the upper end of the support body 411, and a support plate 413 fixed to the lower end of the support body 411. The support 41 is fixed to the lower surface of the frame 12 via the bracket 412. As shown in Fig. 9, the support plate 413 includes a first support piece 4131 extending downward and a second support piece 4132 extending horizontally. A first through hole 414 (see Fig. 11) is formed at the lower end of the first support piece 4131, and a second through hole 415 is formed at the tip of the second support piece 4132. Furthermore, above the first through hole 414 and at the same height as the second through hole 415, a through hole 416 is formed, through which a shoulder screw 42 serving as a rotation axis is inserted. An engagement plate 417 is fixed to the inner surface of this support plate 413.

[0028] The rotating frame 45 includes a pair of rotating arms 451 rotatably attached to the support plate 413 , and a holding arm 452 disposed between the rotating arms 451 . 9 and 11, a locking surface 4511 is formed at the tip of the rotating arm 451, which can lock onto the underside of the engagement plate 417 when the rotating frame 45 is rotated horizontally. Also, an elongated hole 4512 into which a shoulder screw 42 is inserted is formed at the tip of the rotating arm 451. As a result, the rotating frame 45 is attached to the support 41 so as to be rotatable about the shoulder screw 42 as a rotation axis and so as to be slidable by the shoulder screw 42 moving within the elongated hole 4512. Also, two holes 4513 and 4514 are formed at the middle position of the rotating arm 451.

[0029] 9 and 10, the holding arm 452 is formed with a holding piece 4521 capable of holding the edge of the base plate 35. The holding piece 4521 is formed by bending a part of the holding arm 452. The holding arm 452 also has holes formed therein that correspond to the screw holes 36, 37, and 38 formed in the base plate 35. This allows the standard specimen 30 to be fixed to the holding arm 452 via the base plate 35 by inserting the edge of the base plate 35 into the groove of the holding piece 4521 and then screwing a screw through the hole in the holding arm 452 into one of the screw holes 36, 37, or 38 of the base plate 35. The standard specimen 30 can be slid along the longitudinal direction of the holding arm 452 (the left-right direction in FIG. 8 ). The left-right position of the standard specimen 30 can be switched between three levels by selecting the screw hole 36, 37, or 38 that overlaps the hole formed in the center of the holding arm 452 in a plan view. Therefore, the V-notch to be positioned within the scanning range of the laser displacement meter 11 is not limited to V-notch 32 shown in FIG. 8 . By moving the standard specimen 30 to the right or left from the state shown in FIG. 8 , either V-notch 33 or V-notch 34 can be positioned within the scanning range of the laser displacement meter 11.

[0030] The standard sample moving means 40 moves to the inspection position and the storage position by rotating the rotating frame 45. That is, as shown in Figures 8 and 9, the rotating frame 45 is rotated downward about the shoulder screw 42 as the rotation axis, and the rotating frame 45 is slid downward so that the shoulder screw 42 is positioned on the upper end side of the elongated hole 4512. Then, the positioning pin 43 for fixing is inserted into the first through-hole 414 and the upper hole 4513, whereby the rotating frame 45 can be moved and fixed to the inspection position where the standard sample 30 can be measured by the laser displacement meter 11. Meanwhile, the positioning pin 43 is removed from the rotating frame 45 in the inspection position, and the rotating frame 45 is rotated horizontally by 90 degrees using the shoulder screw 42 as the rotation axis. The rotating frame 45 is then slid toward the engagement plate 417 so that the locking surface 4511 engages with the underside of the engagement plate 417 as shown in Figures 10 and 11. The rotating frame 45 is then moved so that the shoulder screw 42 is positioned at the end of the elongated hole 4512 on the holding arm 452 side, and the positioning pin 43 is inserted into the second through hole 415 and the hole 4514. This allows the rotating frame 45 to be moved and fixed to a storage position where the standard sample 30 and the rotating frame 45 do not interfere with the ingot SI.

[0031] Next, a method for V-notching an ingot SI will be described with reference to the flowchart shown in FIG. 12, including the steps of a method for evaluating a V-notch in an ingot SI. First, an ingot SI grown by a semiconductor single crystal growing apparatus is transferred to the grinders 7A to 7D, and the outer periphery of the ingot SI is ground by the grinders 7A to 7D (step S1). After the outer periphery of the ingot SI has been ground, a V-notch VN is formed over the entire length of the ingot SI in the longitudinal direction by the grinders 7A to 7D (step S2).

[0032] After the V-notch VN has been machined, the ingot SI is placed on the holding frame 6 and carried into the stocker 2 for storage (step S3). The operator operates the outgoing workstation 3 to unload the ingot SI together with the holding frame 6 from the stocker 2 (step S4) and place it in the unloading yard. At this time, the ingot number of the ingot SI output from the delivery workstation 3 is also output to the V-notch analysis computer 14.

[0033] The operator operates the operation system 5 to start carrying out the ingot SI to the long length station 8 (step S5). For this purpose, the ingot SI is placed in an unloading yard adjacent to the long length station 8 where the V-notch evaluation device 1 is located. After the ingot SI has been machined to have a V-notch VN by the grinders 7C and 7D, it is placed on the holding frame 6 and then placed directly in the unloading yard where the adjacent V-notch evaluation device 1 is located, without passing through the stocker 2. That is, after step S2, step S5 is performed without performing steps S3 and S4. After the ingot SI starts to be carried out, an air current is blown out from the air blowing mechanism 13 to remove foreign matter such as dust and moisture remaining in the V-notch VN (step S6). After the foreign matter is removed, the processed surface of the V-notch VN is scanned with the laser displacement meter 11 to measure the V-notch VN (step S7).

[0034] The scanning of the machined surface of the V-notch VN is carried out over the entire length of the V-notch VN (step S8), and once scanning of the entire length of the V-notch VN is completed, the shape data acquisition unit 17 of the V-notch analysis computer 14 acquires the measurement values ​​obtained by the laser displacement meter 11 (step S9). The evaluation data generating unit 18 generates evaluation data based on the acquired measurement values ​​(step S10). The quality determining unit 19 determines the quality of the ingot SI based on the generated evaluation data (step S11).

[0035] It is determined whether the V-notch VN of the ingot SI is within the specified range for judgment (step S12). For example, if the specified range for the depth of the V-notch VN is 1.3±0.1 mm, it is determined whether the measured depth of the V-notch VN is within the range of 1.2 mm or more and 1.4 mm or less. If the ingot SI is determined to be non-defective in step S12, the operation system 5 carries the ingot SI out to the next step, the slicing step (step S13). If it is determined to be a defective product, the V-notch analysis computer 14 outputs a message to the operation system 5, and the operation system 5 stops the delivery of the ingot SI and removes it (step S14). As a result of the above, the outer periphery of the ingot SI is ground and the V-notch is machined, and the machined V-notch VN is evaluated so that only non-defective products can be sent to the next process.

[0036] Next, an inspection method for inspecting the V-notch evaluation device 1 will be described based on the flowcharts shown in Figures 13 and 14. When inspecting the V-notch evaluation device 1, a standard sample 30 is measured instead of an ingot SI, and the measurement data is processed using the V-notch analysis computer 14 that is used when measuring the V-notch VN of the ingot SI. FIG. 13 shows a normal inspection method for checking whether the V-notch evaluation device 1 can normally evaluate a V-notch 32 whose depth dimension is within the standard, and is usually performed as part of a daily inspection before work begins. 14 shows a method for abnormality inspection to check whether the V-notch evaluation device 1 can correctly evaluate V-notches 33, 34 whose depth dimensions are out of specification as abnormal, and this method is performed during periodic inspections such as monthly inspections and annual inspections. Note that, like normal inspections, abnormality inspections may also be performed during daily inspections before work begins.

[0037] 13 starts, the inspection worker rotates the rotating frame 45, which has been fixed in the storage position, downward, moves it to the inspection position, and fixes it using the positioning pin 43 (step S21). Since the standard sample 30 is attached to the holding arm 452 of the rotating frame 45, the standard sample 30 also moves to the inspection position. Next, V-notch 32, whose depth dimension is within the standard, is set at a measurement position that can be scanned by laser displacement meter 11 (step S22). Specifically, holding arm 452 has three holes drilled therein that align with screw holes 36 to 38 in base plate 35, and standard sample 30 is positioned by aligning central screw hole 36 in base plate 35 with the central hole in holding arm 452 and screwing a positioning screw into screw hole 36 from below holding arm 452 through the hole in holding arm 452. Note that if V-notch 32 has already been set at the measurement position, it is only necessary to confirm the position of V-notch 32 in step S22.

[0038] Next, the V-notch 32 is measured by the laser displacement meter 11 (step S23). At this time, the scanning of the V-notch 32 of the standard sample 30 does not necessarily have to be performed over the entire length of the V-notch 32, and it is sufficient to scan only the amount necessary for data processing. When scanning of the V-notch 32 is completed, the shape data acquisition unit 17 of the V-notch analysis computer 14 acquires the measurement values ​​acquired by the laser displacement meter 11 (step S24). The evaluation data generating unit 18 generates evaluation data based on the acquired measurement values ​​(step S25). The pass / fail judgment unit 19 judges the pass / fail of the V-notch 32 of the standard sample 30 based on the generated evaluation data (step S26). Since the depth dimension of the V-notch 32 is within the standard, the pass / fail judgment unit 19 normally judges it to be pass. Therefore, the inspector checks whether the pass / fail judgment unit 19 has judged it to be pass (step S27).

[0039] If the result is judged to be good in step S27, the inspection worker determines that the V-notch evaluation device 1 is normal (step S28), and if the result is judged to be bad in step S27, the inspection worker determines that there is an abnormality in the V-notch evaluation device 1 (step S29). Thereafter, the inspector removes the positioning pins 43 that have been fixing the rotating frame 45, moves the rotating frame 45 to a storage position, and fixes it with the positioning pins 43, thereby completing the inspection (step S30). If an abnormality is determined in step S29, the inspection worker should check the cause of the abnormality in the V-notch evaluation device 1, and if the cause is dust adhering to the light receiving unit 11B, for example, he or she should take measures to address the cause of the abnormality, such as cleaning the laser displacement meter 11. After that, he or she should perform a normal inspection again, and after confirming that the V-notch evaluation device 1 is normal, he or she should proceed with the evaluation of the V-notch VN of the ingot SI.

[0040] 14 is started, the inspection worker rotates the rotating frame 45 downward, moves it to the inspection position, and fixes it using the positioning pin 43 (step S31). When an abnormality inspection is performed following a normal inspection, the inspection work can be continued without returning the rotating frame 45 to the storage position after the regular inspection is completed. Next, the V-notch 33, which has an out-of-standard depth dimension, is set as the measurement position of the laser displacement meter 11 (step S32). Specifically, the screw hole 37 on the left side of the base plate 35 is aligned with the central hole of the holding arm 452, and a positioning screw is screwed into the screw hole 37 from below the holding arm 452 through the hole in the holding arm 452, thereby positioning the standard sample 30.

[0041] Next, similar to steps S23 to S26 during normal inspection, the V-notch 33 is measured using the laser displacement meter 11 (step S33), and once scanning of the V-notch 33 is complete, the shape data acquisition unit 17 of the V-notch analysis computer 14 acquires the measurement values ​​acquired by the laser displacement meter 11 (step S34), and the evaluation data generation unit 18 generates evaluation data based on the acquired measurement values ​​(step S35). Note that, since each of the V-notches 32, 33, 34 is formed on one arcuate surface 31, the depth direction of the central V-notch 32 is a vertical direction perpendicular to the bottom surface of the standard sample 30, but the depth directions of the left and right V-notches 33, 34 are inclined with respect to the direction perpendicular to the bottom surface of the standard sample 30. For this reason, when measuring the V-notches 33, 34, the evaluation data generation unit 18 performs rotational movement so that the machined surfaces of the V-notches 33, 34 face directly upward, as in the case of measuring the V-notch VN, and then performs translational movement so that the bottoms of the machined surfaces of the V-notches 33, 34 become the origin, thereby generating evaluation data. The quality judging section 19 judges the quality of the V-notch 33 of the standard sample 30 based on the generated evaluation data (step S36). Next, the inspector checks whether the quality determining unit 19 has determined that the product is good (step S37). Since the V-notch 33 is out of specification, that is, its depth dimension is smaller than the standard, the quality determining unit 19 would normally determine that the product is bad.

[0042] Therefore, if the result is judged to be good in step S37, the inspection worker determines that there is an abnormality in the V-notch evaluation device 1 (step S38), and if the result is judged to be bad in step S37, the inspection worker determines that the V-notch evaluation device 1 is operating normally (step S39). Next, the inspector confirms whether the inspection may be terminated (step S40). In this embodiment, two non-standard V-notches 33 and 34 are formed in the standard specimen 30, and since the inspection of the V-notch 34 is to be performed after the inspection of the V-notch 33, the determination in step S40 is NO, and the V-notch 34, whose depth dimension is non-standard, is set as the inspection position of the laser displacement meter 11 (step S32). Specifically, the screw hole 38 on the right side of the base plate 35 is aligned with the central hole of the holding arm 452, and a positioning screw is screwed into the screw hole 38 from below the holding arm 452 through the hole in the holding arm 452, thereby positioning the standard specimen 30.

[0043] Thereafter, the processes of steps S33 to S36 are executed again. Next, the inspector checks whether the quality determining unit 19 has determined that the product is good (step S37). Since the V-notch 33 is out of specification, that is, its depth dimension is greater than the standard, the quality determining unit 19 would normally determine that the product is bad. Therefore, if the result is judged to be good in step S37, the inspection worker determines that there is an abnormality in the V-notch evaluation device 1 (step S38), and if the result is judged to be bad in step S37, the inspection worker determines that the V-notch evaluation device 1 is operating normally (step S39). Next, the inspection worker confirms whether it is OK to end the inspection (step S40), and if it is OK to end, the judgment in step S40 is Yes, and the inspection worker removes the positioning pin 43 that was fixing the rotating frame 45, moves the rotating frame 45 to a storage position and fixes it with the positioning pin 43 (step S41), thereby ending the inspection. Furthermore, if the non-standard V-notches 33 and 34 are judged to be normal in step S39, the inspection worker should check the cause of the abnormality in the V-notch evaluation device 1, take measures such as cleaning the laser displacement meter 11, and then perform the abnormality inspection again.After confirming that the V-notch evaluation device 1 is operating normally, the worker can then perform the evaluation work of the V-notch VN of the ingot SI.

[0044] According to this embodiment, the following effects are obtained. In this embodiment, a standard sample 30 is prepared by cutting from an ingot SI and machining V-notches 32, 33, and 34 for inspection, and a standard sample moving means 40 to which this standard sample 30 is fixed is installed in the V-notch evaluation device 1.Therefore, when inspecting the V-notch evaluation device 1, it is only necessary to rotate the rotating frame 45 of the standard sample moving means 40 to the inspection position and fix it with the positioning pin 43, so that the V-notch evaluation device 1 can be inspected quickly and easily. That is, one possible method is to prepare a sample ingot by machining a V-notch for inspection into a grown semiconductor single crystal ingot SI, and then transport this sample ingot from stocker 2 to V-notch evaluation apparatus 1 for inspection. However, this method requires securing a storage space for the sample ingot, and it also requires that the sample ingot be transported from stocker 2 to a position where it will be measured by V-notch evaluation apparatus 1, and then returned to stocker 2 after inspection, which increases the amount of work required. In contrast, in this embodiment, standard sample 30 is minimized to a size that can be attached to V-notch evaluation apparatus 1 and is fixed to rotating frame 45 of standard sample moving means 40, so that the amount of work required to move standard sample 30 to the inspection position can be minimized, thereby improving work efficiency during inspection.

[0045] In this embodiment, a plurality of V-notches are formed in the standard specimen 30, including a V-notch 32 for normality determination whose depth dimension is within the standard, and V-notches 33 and 34 for abnormality determination whose depth dimension is outside the standard. Therefore, using one standard specimen 30, it is possible to perform a normality inspection to check whether the V-notch 32 for normality determination can be correctly determined to be normal, and an abnormality inspection to check whether the V-notches 33 and 34 for abnormality determination can be correctly determined to be abnormal, and the measurement accuracy of the V-notch evaluation device 1 can be easily maintained and managed.

[0046] In this embodiment, the standard specimen moving means 40 is configured to include a support 41 and a rotating frame 45 to which the standard specimen 30 is attached, and the inspection work of the measurement accuracy can be performed simply by rotating the rotating frame 45 90 degrees from the storage position, moving it to the inspection position, and fixing it with the positioning pin 43, so that the inspection work can be started with a minimum of man-hours. Furthermore, by rotating the rotating frame 45 90 degrees from the inspection position, moving it to the storage position, and fixing it with the positioning pin 43, it is possible to prevent the standard specimen moving means 40 and the standard specimen 30 from interfering with the ingot SI when measuring the V-notch VN of the ingot SI thereafter, and the transition from the inspection work to the normal evaluation work can also be realized with a minimum of man-hours.

[0047] In this embodiment, the V-notch VN formed in the ingot SI is scanned along the longitudinal direction of the ingot SI by the laser displacement meter 11, and shape data of the machined surface of the V-notch VN can be acquired over the entire length of the V-notch VN. Therefore, the acquired shape data of the machined surface of the V-notch VN is used to generate evaluation data by coordinate transformation, and the entire V-notch VN can be evaluated, allowing for highly accurate pass / fail judgment of the V-notch VN. Furthermore, data measured by the laser displacement meter 11 for the V-notches 32, 33, and 34 of the standard sample 30 during inspection is processed and judged using the shape data acquisition unit 17, evaluation data generation unit 18, and pass / fail judgment unit 19, which process measurement data for the V-notch VN of the ingot SI, so that it is possible to judge not only defects in the laser displacement meter 11, but also defects in the shape data acquisition unit 17, evaluation data generation unit 18, and pass / fail judgment unit 19. Therefore, when the program is updated due to system improvements, etc., it is possible to check for program bugs by checking whether the V-notches 32, 33, and 34 of the standard sample 30 can be correctly judged.

[0048] Since the standard specimen 30 is made of a block cut out from a silicon single crystal ingot SI, it can be a silicon standard specimen 30 whose shape is stable and can be used for a long period of time as the standard specimen 30. In addition, the shape of the V-notch machined by a grinding wheel can be reproduced, and it is possible to easily form a V-notch 32 with a depth dimension within the standard and V-notches 33 and 34 with depth dimensions outside the standard.

[0049] In this embodiment, the V-notch VN of an ingot SI that has been V-notched can be evaluated for quality using a V-notch evaluation method for an ingot SI, thereby eliminating ingots with defects in the V-notch VN. Therefore, in the next slicing process, defective products due to defects in the V-notch VN can be eliminated, reducing unnecessary processing in the slicing process. In this embodiment, an air blowing mechanism 13 is provided in front of the scanning direction of the laser displacement meter 11. Therefore, after machining the V-notch VN of the ingot SI, dust and cutting water adhering to the V-notch VN can be removed, allowing scanning by the laser displacement meter 11 to be performed in a clean state, thereby improving the accuracy of measuring the V-notch shape.

[0050] [Variations] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and various improvements and design changes that do not deviate from the gist of the present invention are also included in the present invention. The standard sample is not limited to one made of the same material as a semiconductor single crystal ingot such as silicon, but may be made of a metal such as stainless steel or a synthetic resin, as long as it is a material that can form V-notches 32, 33, and 34 and can be measured by the laser displacement meter 11. The shape of the standard sample is not limited to that of the above embodiment, and for example, a standard sample 30B shown in Fig. 15 may be used. Standard sample 30B has three arcuate surfaces 31 formed thereon, each having the same curvature as the outer peripheral surface of ingot SI, and V-notches 32, 33, and 34 formed at the apex of each arcuate surface 31. With this standard sample 30B, when each V-notch 32, 33, and 34 is moved to a measurement position directly below laser displacement meter 11 by sliding it on holding arm 452, the orientation of each V-notch 32, 33, and 34 can be kept constant.

[0051] The number of V-notches formed in the standard specimen is not limited to 3. For example, the standard specimen may have one V-notch within the specification, or two or four or more V-notches. Furthermore, the V-notches formed in the standard specimens are not limited to those with depth dimensions that are within or outside the standard, and may be set based on the indices used to evaluate the V-notches. For example, if the evaluation indices include the width dimension of the V-notch VN, the angle of the inclined surface of the V-notch VN, and the shape of the V-notch VN, in addition to the depth dimension, standard specimens having V-notches that are within or outside the standard for each indices may be used. In this case, a different standard specimen may be prepared for each indices and attached to the holding arm 452, or multiple rotating frames 45 may be provided, with different standard specimens attached to each rotating frame 45, and the multiple rotating frames 45 may be moved sequentially to the inspection position for inspection.

[0052] The standard sample 30 was moved horizontally relative to the holding arm 452, but it may also be moved in an arc direction relative to the holding arm 452, and when each V-notch 33, 34 is moved to the measurement position, the opening direction of the V-notches 33, 34 may be set to face vertically, the same as the V-notch 32.

[0053] The standard sample moving means is not limited to the configuration of the above embodiment, and may be configured, for example, by a holding stage on which the standard sample 30 is held, and a moving device that slides the holding stage between an inspection position and a storage position. [Explanation of symbols]

[0054] 1...V-notch evaluation device, 2...storage, 3...delivery workstation, 4...carry-out device, 5...operation system, 6...holding frame, 7A...grinder, 7B...grinder, 7C...grinder, 7D...grinder, 8...long-length station, 11...laser displacement meter, 11A...light-emitting unit, 11B...light-receiving unit, 12...frame, 13...air blow mechanism, 14...V-notch analysis computer, 15...arithmetic processing unit, 16...storage device, 17...shape data acquisition unit, 18...evaluation data generation unit, 19...good / bad judgment unit, 2 0...evaluation result recording unit, 30...standard sample, 30B...standard sample, 31...arc surface, 32...V notch, 33...V notch, 34...V notch, 35...base plate, 40...standard sample moving means, 41...support, 42...step screw, 43...positioning pin, 45...rotating frame, 411...support main body, 412...bracket, 413...support plate, 417...engagement plate, 451...rotating arm, 452...holding arm, 4131...first support piece, 4132...second support piece, 4521...holding piece, SI...ingot, VN...V notch.

Claims

1. 1. An ingot V-notch evaluation device for evaluating a V-notch formed in the longitudinal direction of a semiconductor single crystal ingot, comprising: an optical measurement means having a light emitting unit and a light receiving unit, and scanning the shape of the V-notch; a moving means for relatively moving the ingot or the optical measuring means in the longitudinal direction of the ingot; a data processing means for processing V-notch shape data obtained by scanning with the optical measuring means; a standard sample moving means for holding a standard sample having a V-notch formed therein for inspection and capable of moving the standard sample to an inspection position and a storage position; the inspection position is a position where the V-notch shape of the standard sample can be measured by the optical measurement means, The storage position is a position that does not interfere with the ingots moved by the moving means. An ingot V-notch evaluation device.

2. 2. The ingot V-notch evaluation device according to claim 1, The standard sample has multiple V-notches formed therein. An ingot V-notch evaluation device.

3. 3. The ingot V-notch evaluation device according to claim 2, The plurality of V-notches include a V-notch for determining normality and a V-notch for determining abnormality. An ingot V-notch evaluation device.

4. 2. The ingot V-notch evaluation device according to claim 1, the standard sample moving means is configured to include a support column and a rotating frame that is rotatably provided on the support column and is movable between the inspection position and the storage position, and that holds the standard sample; The rotating frame is configured to be fixable to the support column at each of the inspection position and the storage position. An ingot V-notch evaluation device.

5. 2. The ingot V-notch evaluation device according to claim 1, The standard sample moving means comprises a holding stage on which the standard sample is held, and a moving device that slides the holding stage between the inspection position and the storage position. An ingot V-notch evaluation device.

6. 2. The ingot V-notch evaluation device according to claim 1, The data processing means a shape data acquisition unit that acquires V-notch shape data measured by the optical measurement means; an evaluation data generating unit that performs coordinate transformation on the acquired V-notch shape data and generates evaluation data for evaluating the V-notch shape; a quality determination unit that determines whether the V-notch shape is good or bad based on the generated evaluation data; Equipped with An ingot V-notch evaluation device.

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