TWI852697B - Evaluation device for v-notch of ingot - Google Patents

Abstract

[Subject] To provide an evaluation device for a V-notch of ingot of single crystals for semiconductors that can easily inspect measurement accuracy. [Solution] The evaluation device for a V-notch of ingot 1 includes a laser displacement meter 11, equipped with a light emitter and a light receiver, and scanning the V-notch shape; a moving means, moving the ingot or the laser displacement meter 11 relative to the longitudinal direction of the ingot; a data processing means, processing V-notch shape data obtained by the scanning of the laser displacement meter 11; and a standard sample moving means 40, holding a standard sample 30 with V-notches 32, 33, 34 for evaluation formed thereon. The standard sample moving is able to move to an inspection position, where the laser displacement meter 11 can measure the V-notch shape of the standard sample 30, and to a storage position, where it does not interfere with the ingot being moved by the moving means.

Description

V-notch evaluation device for ingots

The present invention relates to a V-notch evaluation device for ingots.

In the past, a V-notch was formed at the end of a silicon wafer as a mark indicating the crystal orientation. This V-notch of a silicon wafer is formed by grinding the outer periphery of a grown silicon single crystal ingot, then forming a V-shaped groove in the longitudinal direction of the ingot using a grindstone, and then cutting the ingot to the thickness of the silicon wafer. If the V-notch of a silicon wafer has defects, such as deterioration or cracking of the grindstone, it cannot maintain a standard shape, and wafer cracks may occur starting from the V-notch in the subsequent wafer processing process.

Therefore, in Patent Document 1, a V-notch evaluation device for an ingot is disclosed, which can measure the shape of the V-notch formed in the longitudinal direction of the ingot and can make a good or bad judgment with high precision. This V-notch evaluation device for an ingot includes: an optical measuring tool, including a light emitting part and a light receiving part, scanning the shape of the V-notch; a moving tool, moving the ingot and the optical measuring tool relatively in the longitudinal direction of the ingot; and a data processing tool, processing the V-notch shape data obtained by scanning the optical measuring tool. The aforementioned data processing tool includes: a shape data acquisition unit, which acquires the V-notch shape data measured by the aforementioned optical measurement tool; an evaluation data generation unit, which performs coordinate transformation of the acquired V-notch shape data to generate evaluation data for evaluating the aforementioned V-notch shape; and a quality judgment unit, which judges the quality of the aforementioned V-notch shape based on the generated evaluation data. [Prior technical literature] [Patent literature]

[Patent Document 1] Japanese Patent No. 7035923

[Problem to be solved]

In the aforementioned V-notch evaluation device, for example, if the measurement accuracy is reduced due to dust adhering to the light receiving part, a normal V-notch may be misjudged as abnormal, or a defective V-notch may be misjudged as normal. Therefore, in order to maintain and manage the measurement accuracy of the V-notch evaluation device, it is necessary to be able to simply check the measurement accuracy of the V-notch evaluation device during the pre-startup inspection. The purpose of the present invention is to provide a V-notch evaluation device for semiconductor single crystal ingots that can simply check the measurement accuracy. [Method for solving the problem]

The present invention is a V-notch evaluation device for an ingot, which evaluates the V-notch formed in the longitudinal direction of a single crystal ingot for semiconductors, and includes: an optical measuring tool, including a light-emitting part and a light-receiving part, which scans the shape of the V-notch; a moving tool, which relatively moves the ingot or the optical measuring tool in the longitudinal direction of the ingot; a data processing tool, which processes the V-notch shape data obtained by scanning the optical measuring tool; and a standard sample moving tool, which holds a standard sample formed with a V-notch for inspection and can be moved 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 measuring tool, and the storage position is a position that does not interfere with the ingot moved by the moving tool.

In the V-notch evaluation device for ingots of the present invention, the standard sample is preferably formed with a plurality of V-notches.

In the V-notch evaluation device for ingots of the present invention, the plurality of V-notches preferably include a V-notch for normal determination and a V-notch for abnormal determination.

In the V-notch evaluation device for cast ingots of the present invention, the standard sample moving tool is preferably constructed to include a support and a rotating frame, and the rotating frame is configured to be rotatable relative to the support, and can be moved to the inspection position and the storage position, and hold the standard sample. The rotating frame is preferably constructed to be fixed to the support at the inspection position and the storage position, respectively.

In the V-notch evaluation device for cast ingots of the present invention, the standard sample moving tool is preferably constructed to include a holding table and a moving device, the holding table holds the standard sample, and the moving device slides the holding table to the inspection position and the storage position.

In the V-notch evaluation device for cast ingots of the present invention, the aforementioned data processing tool preferably includes: a shape data acquisition unit, which acquires the V-notch shape data measured by the aforementioned optical measurement tool; an evaluation data generation unit, which performs coordinate transformation of the acquired V-notch shape data to generate evaluation data for evaluating the aforementioned V-notch shape; and a quality judgment unit, which judges the quality of the aforementioned V-notch shape based on the generated evaluation data.

In FIG. 1, a V-notch evaluation device 1 according to an embodiment of the present invention is shown. The V-notch evaluation method using the V-notch evaluation device 1 is implemented after the peripheral grinding of the grown semiconductor single crystal ingot SI and the processing of the V-notch VN is completed, and before it is sent to the cutting process as the next process. As a representative semiconductor single crystal, including silicon single crystal, the V-notch evaluation device 1 of the present invention can be used to evaluate the V-notch formed in the silicon single crystal ingot SI. Furthermore, if it can be measured by the optical measurement tool described below, the V-notch evaluation device 1 of the present invention can also be used to evaluate the V-notch formed in the semiconductor single crystal ingot SI other than the silicon single crystal. Specifically, as shown in FIG. 2, the grown semiconductor single crystal ingot SI is sent from the storage 2 to the grinders 7A to 7D. The grinders 7A to 7D grind the outer periphery of the ingot SI and process the V-notch VN. The ingot SI subjected to the V-notch VN process is evaluated by the V-notch evaluation device 1. The V-notch evaluation device 1 is arranged between the storage 2 and the long station 8, or between the storage 2 and the grinders 7C and 7D. The long station 8 is a place for temporarily storing the ingot SI sent from the storage 2.

As shown in FIG. 1, the outbound control of the ingot SI from the storage 2 to the grinder 7A to the grinder 7D and the long station 8 is performed at the outbound workstation 3. When the number of the ingot SI is input to the outbound workstation 3, the number is output to the unloading device 4. The unloading device 4 carries the ingot SI corresponding to the number input from the storage 2 on the holding frame 6 and carries it out to the unloading yard. Based on the instruction of the operating system 5, the ingot SI is carried out from the unloading yard to the grinder 7A to the grinder 7D and the long station 8.

The V-notch evaluation device 1 is arranged at the unloading site to evaluate the V-notch VN processed on the ingot SI unloaded to the unloading site. The V-notch evaluation device 1 includes a laser displacement meter 11, a frame 12, an air supply mechanism 13, and a computer 14 for V-notch analysis. As shown in FIG. 3, the laser displacement meter 11 as an optical measurement tool includes a light-emitting part 11A, a light-receiving part 11B, and a measurement value output cable 11C. In addition, the optical measurement tool is not limited to the laser displacement meter 11, and may also be a tool that can optically measure the V-notch VN in a non-contact manner.

Although omitted in the figure, the light-emitting part 11A includes a laser oscillator and a cylindrical lens. The laser light emitted by the laser oscillator is converted into a strip laser light by the cylindrical lens, and the width becomes wider with the distance (as shown in Figure 3), and irradiates the V-notch VN. Although omitted in the figure, the light-receiving part 11B includes a light-collecting lens group and a CMOS sensor. The reflected light of the laser light irradiated from the light-emitting part 11A to the V-notch VN is collected by the light-collecting lens group of the light-receiving part 11B, and an image is formed on the CMOS sensor to measure the shape of the V-notch VN.

The measurement data of the V-notch VN measured by the light receiving part 11B is output to the V-notch analysis computer 14 through the measurement value output cable 11C. The laser displacement meter 11 of this embodiment can measure the V-notch VN at 64 kHz. At a predetermined speed, the ingot SI and the laser displacement meter 11 are relatively moved and scanned, thereby measuring the shape of the V-notch VN formed in the longitudinal direction of the ingot SI multiple times over the entire length in a short time.

The frame 12 as a holding tool is made of a metal material with an inverted L-shaped side surface. The frame 12 faces the ingot SI, and its base end side in the direction of carrying out the ingot SI is buried in the carrying-out field, and the front end side in the direction of carrying out is suspended in the air. The laser displacement meter 11 is suspended on the lower surface of the front end side of the frame 12. The laser displacement meter 11 can scan the V notch VN along the longitudinal direction of the ingot SI from a bird's-eye view of the ingot SI. In addition, the V notch VN scanning by the laser displacement meter 11 is implemented by instructions from the operating system 5. The above-mentioned scanning is performed in the V-notch evaluation device 1 installed in combination with the grinder 7C and the grinder 7D when the ingot SI processed by the grinder 7C and the grinder 7D is transported to the storage 2. In addition, in the V-notch evaluation device 1 parallel to the long station 8, the above-mentioned scanning is performed when the ingot SI processed by the grinder 7A and the grinder 7B returns to the storage 2 and is transported from the storage 2 to the long station 8. That is, in this embodiment, the mechanism for transporting the ingot SI between the storage 2 and the long station 8 and the mechanism for transporting the storage 2 between the storage 2 and the grinder 7C and the grinder 7D act as a moving tool. Furthermore, the present invention is not limited thereto, and the moving tool may be formed by other transport mechanisms such as a conveyor belt, and may also be used as a moving tool that can move the laser displacement meter 11 in the longitudinal direction of the ingot SI.

The air supply mechanism 13 as a foreign matter removal tool is provided on the base end side of the laser displacement meter 11 in the carrying-out direction and is mounted on the lower surface of the frame 12. The air supply mechanism 13 blows airflow with a width corresponding to the laser scanning width of the laser displacement meter 11 to the V-notch VN. By blowing airflow in the front section of the laser displacement meter 11, dust and moisture attached to the V-notch VN in the peripheral grinding process and notch forming process as the previous process can be blown away, thereby enabling the laser displacement meter 11 to scan the surface of the V-notch VN in a clean state.

As shown in FIG. 4, the V-notch analysis computer 14 as a data processing tool obtains the V-notch VN measurement value output by the measurement value output cable 11C of the laser displacement meter 11, and is used to determine the processing shape of the V-notch VN. The V-notch analysis computer 14 is composed of a general-purpose computer including an arithmetic processing device 15 and a storage device 16 such as an SD memory or a hard disk. The V-notch analysis computer 14 includes a shape data acquisition unit 17 executed on the arithmetic processing device 15, an evaluation data generation unit 18, a quality determination unit 19, and an evaluation result recording unit 20 provided in the storage device 16.

The shape data acquisition unit 17 acquires the V-notch VN measurement value (V-notch shape data) output from the laser displacement meter 11 through the measurement value output cable 11C. Specifically, as shown in FIG. 5 , the shape data acquisition unit 17 acquires the transverse length position (the width direction position of the V-notch VN) and the longitudinal position (the depth direction position of the V-notch VN) of the V-notch VN as the measurement value. Since the laser displacement meter 11 moves relatively to acquire the measurement value of the entire length of the V-notch VN, the shape data acquisition unit 17 acquires the transverse position and the longitudinal position of the entire length of the V-notch VN as the measurement value. The acquired measurement value is output to the evaluation data generation unit 18.

The evaluation data generation unit 18 transforms the V-notch VN measurement value coordinates obtained by the shape data acquisition unit 17 into a form that can be judged by the quality judgment unit 19. The evaluation data generation unit 18 transforms the obtained measurement value coordinates using an affine transformation matrix of magnification, reduction, translation, rotation, and tilt, and generates evaluation data. Specifically, as shown in FIG. 6, the evaluation data generation unit 18 first performs a rotational movement so that the processed surface of the V-notch VN faces directly upward. Next, the evaluation data generation unit 18 performs a parallel movement so that the bottom of the V-notch VN processed surface is used as the origin to generate evaluation data. The generated evaluation data is output to the quality judgment unit 19.

Furthermore, in this embodiment, although the evaluation data generating unit 18 uses an affine transformation matrix to perform coordinate transformation, the present invention is not limited to this. For example, when the laser displacement meter 11 scans from the oblique upper side of the V-notch VN, because the scanned surface is deformed into a trapezoid with depth, the coordinate transformation can also be performed using a projection transformation matrix. In addition, as described above, the purpose of the present invention is to determine the quality of the V-notch shape of a single crystal wafer for semiconductors as a final product in the ingot state. Therefore, it is preferable to transform the evaluation data coordinates into the same V-notch shape as that on the cutting surface in the subsequent cutting process.

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 compares the depth dimension of the V notch VN, the width dimension of the V notch VN, the inclination angle of the V notch VN, and the shape of the V notch VN with the preset evaluation reference value to determine the quality of the V notch VN. In addition, the quality determination unit 19 is not limited to determining the quality based on the above four items. For example, it can also determine the quality by evaluating only the depth dimension of the V notch VN.

In the V-notch evaluation device 1, a standard sample 30 and a standard sample moving tool 40 are provided. The standard sample 30 is used to maintain and manage the measurement accuracy during the inspection operation. The standard sample moving tool 40 moves the above-mentioned standard sample 30 to the inspection position and the storage position. As shown in FIG. 7, the standard sample 30 is a block-shaped member cut from the ingot SI, and three V-notches 32, 33, and 34 are machined on the outer peripheral surface of the ingot SI, i.e., the arc surface 31. In this embodiment, the three V-notches 32, 33, and 34 are machined according to the depth dimension standard of the V-notch VN. The central V-notch 32 is a V-notch within the standard, and is machined to the standard central value of the depth dimension of the V-notch VN. The V-notch 33 on the left side of Figure 7 is a non-standard V-notch, which is processed to exceed the lower limit of the depth dimension of the V-notch VN. The V-notch 34 on the right side is a non-standard V-notch, which is processed to exceed the upper limit of the depth dimension of the V-notch VN. The depth dimension settings of each V-notch 32, V-notch 33, and V-notch 34 are determined according to the product specifications, but for example, the standard value of the depth dimension of the V-notch VN is 1.3±0.1 mm, the depth dimension of the V-notch 32 is the standard central value, that is, 1.3 mm, the depth dimension of the V-notch 33 is 1.1 mm, which is smaller than the lower limit of the standard value, and the depth dimension of the V-notch 34 is 1.5 mm, which is larger than the upper limit of the standard value. The intervals between each V-notch 32, V-notch 33, and V-notch 34 are set to a distance at which the plurality of V-notches 32, V-notch 33, and V-notch 34 will not enter the measurement range of the laser displacement meter 11. In the standard sample 30 of this embodiment, each V-notch 32, V-notch 33, and V-notch 34 is formed with an interval of 20 mm. In addition, for example, the size of the standard sample 30 is 80 mm in width, 30 mm in depth, and 15 mm in height. This is the minimum size that can form three V-notches 32, V-notch 33, and V-notch 34 at a fixed interval.

The standard sample 30 is then fixed to a stainless steel base plate 35. On the base plate 35, screw holes 36, 37, and 38 for positioning are formed according to the positions of the V-notches 32, 33, and 34. Therefore, the intervals between the screw holes 36, 37, and 38 are the same as those between the V-notches 32, 33, and 34, and are formed at intervals of 20 mm.

As shown in FIGS. 8 to 11, the standard sample moving tool 40 is configured to include a pair of pillars 41 fixed to the frame 12 and a rotating frame 45 that can be rotatably mounted relative to the pillars 41. The pillar 41 includes a pillar body 411 in the shape of a prism, a bracket 412 fixed to the upper end of the pillar body 411, and a support plate 413 fixed to the lower end of the pillar body 411. The pillar 41 is fixed to the lower surface of the frame 12 by 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 is formed at the lower end of the first support piece 4131 (see FIG. 11). A second through hole 415 is formed at the front end of the second support piece 4132. In addition, a through hole 416 is formed above the first through hole 414 and at the same height as the second through hole 415, and a shoulder screw 42 serving as a rotation axis is inserted therein. A coupling plate 417 is fixed to the inner surface of the above-mentioned support plate 413.

The rotating frame 45 includes a pair of rotating arms 451 that can be rotatably mounted relative to the support plate 413 and a retaining arm 452 disposed between the rotating arms 451. As shown in Figures 9 and 11, the front end of the rotating arm 451 is formed with a locking surface 4511, which can lock the lower surface of the coupling plate 417 when the rotating frame 45 rotates in the horizontal direction. In addition, the front end of the rotating arm 451 is formed with a long hole 4512, into which the shoulder screw 42 is inserted. Thereby, the rotating frame 45 is rotatably mounted on the support 41 with the shoulder screw 42 as a rotating axis, and is slidably mounted on the support 41 by the shoulder screw 42 moving in the long hole 4512. In addition, two holes 4513 and 4514 are formed at the middle position of the rotating arm 451.

As shown in FIG. 9 and FIG. 10, a retaining piece 4521 is formed on the retaining arm 452 to retain the edge of the substrate 35. The retaining piece 4521 is formed by bending a portion of the retaining arm 452. In addition, holes corresponding to the screw holes 36, 37, and 38 formed on the substrate 35 are formed on the retaining arm 452. Thereby, since the edge of the substrate 35 is inserted into the groove of the retaining piece 4521, and the screw is further screwed from the hole of the retaining arm 452 to any one of the screw holes 36, 37, and 38 of the substrate 35, the standard sample 30 can be fixed to the retaining arm 452 through the substrate 35. In addition, the standard sample 30 can slide along the longitudinal direction of the holding arm 452 (left and right direction in FIG. 8), and the left and right position of the standard sample 30 can be switched between three stages by selecting the screw hole 36, screw hole 37, and screw hole 38 that overlap with the hole formed in the center of the holding arm 452 in the plane view. Therefore, the V-notch arranged in the scanning range of the laser displacement meter 11 is not limited to the V-notch 32 shown in FIG. 8. By moving the standard sample 30 to the right or left from the state shown in FIG. 8, the V-notch 33 or the V-notch 34 can be arranged in the scanning range of the laser displacement meter 11.

The standard sample moving tool 40 is moved to the inspection position and the storage position by rotating the rotating frame 45. In other words, as shown in Figures 8 and 9, the rotating frame 45 is rotated downward with the shoulder screw 42 as the rotation axis, and the rotating frame 45 is slid downward so that the shoulder screw 42 is located at the upper end side of the long hole 4512, and the positioning pin 43 for fixing is inserted into the first through hole 414 and the upper hole 4513, thereby moving and fixing the rotating frame 45 to the inspection position where the standard sample 30 can be measured by the laser displacement meter 11. On the other hand, the positioning pin 43 is removed from the rotating frame 45 located at the inspection position, and the rotating frame 45 is rotated 90 degrees in the horizontal direction with the shoulder screw 42 as the rotation axis. As shown in Figures 10 and 11, the rotating frame 45 is slid toward the side of the engaging plate 417 so that the locking surface 4511 engages with the lower surface of the engaging plate 417. The rotating frame 45 is moved so that the shoulder screw 42 is located at the end of the holding arm 452 side of the long hole 4512, and the positioning pin 43 is inserted into the second through hole 415 and the hole 4514, thereby moving and fixing the rotating frame 45 to the standard sample 30 and the storage position where the rotating frame 45 does not interfere with the ingot SI.

Next, the V-notch processing method of the ingot SI, including the sequence of the V-notch evaluation method of the ingot SI, is explained based on the flowchart shown in FIG. 12. First, the ingot SI grown by the semiconductor single crystal growth device is transported to the grinder 7A to the grinder 7D, and the outer periphery of the ingot SI is ground by the grinder 7A to the grinder 7D (process S1). After the outer periphery of the ingot SI is ground, the V-notch VN processing is performed on the entire length of the ingot SI in the longitudinal direction by the grinder 7A to the grinder 7D (process S2).

After the V-notch VN processing is completed, the ingot SI is placed on the holding frame 6 and moved into and stored in the storage 2 (process S3). The operator operates the outbound workstation 3 to simultaneously move the ingot SI and the holding frame 6 out of the storage 2 (process S4) and place them in the outbound field. At this time, the ingot number of the ingot SI output from the outbound workstation 3 is also output to the V-notch analysis computer 14.

The operator operates the operating system 5 to start unloading the ingot SI to the long station 8 (process S5). Therefore, the ingot SI is arranged in the unloading area where the V-notch evaluation device 1 adjacent to the long station 8 is arranged. And, after the ingot SI processed by the grinder 7C and the grinder 7D with the V-notch VN is placed on the holding frame 6, it is directly arranged in the unloading area where the adjacent V-notch evaluation device 1 is arranged without passing through the storage 2. In other words, after process S2, process S3 and process S4 are not executed, but process S5 is directly executed. After the unloading of the ingot SI starts, the air flow is ejected from the air supply mechanism 13 to remove foreign matter such as dust and moisture remaining in the V-notch VN (process S6). After removing the foreign matter, the laser displacement meter 11 is used to scan the processed surface of the V-notch VN to measure the V-notch VN (process S7).

The V-notch VN processing surface is scanned along the entire length of the V-notch VN (process S8). After the full-length scan of the V-notch VN is completed, the shape data acquisition unit 17 of the V-notch analysis computer 14 acquires the measurement value acquired by the laser displacement meter 11 (process S9). The evaluation data generation unit 18 generates evaluation data based on the acquired measurement value (process S10). The quality judgment unit 19 performs quality judgment of the ingot SI based on the generated evaluation data (process S11).

Determine whether the V-notch VN processing of the ingot SI is within the standard value for determination (process S12). For example, if the standard value for the depth dimension of the V-notch VN is 1.3±0.1 mm, determine whether the measured depth dimension of the V-notch VN is within the range of 1.2 mm or more and 1.4 mm or less. If it is determined to be a qualified product in process S12, the operating system 5 will move the ingot SI to the cutting process as the next process (process S13). If it is determined to be an unqualified product, the above situation will be output from the V-notch analysis computer 14 to the operating system 5. The operation system 5 stops the removal of the ingot SI and removes it (process S14) Through the above, the outer periphery of the ingot SI can be ground and V-notched, and the V-notch VN after processing can be evaluated, and only qualified products can be removed to the next process.

Next, the inspection method of the V-notch evaluation device 1 is explained based on the flow chart shown in Figures 13 and 14. When inspecting the V-notch evaluation device 1, the standard sample 30 is measured instead of the ingot SI, and the V-notch analysis computer 14 used for the V-notch VN measurement of the ingot SI is directly used to process the measurement data. Figure 13 shows the method for normal inspection, which is used to check whether the V-notch evaluation device 1 can evaluate the V-notch 32 within the depth dimension standard as normal. Usually, it is performed during the inspection before daily startup. Figure 14 shows the method for abnormal inspection, which is used to check whether the V-notch evaluation device 1 can correctly evaluate the V-notch 33 and V-notch 34 outside the depth dimension standard as abnormal. It is performed during regular inspections such as monthly or annual inspections. In addition, the abnormal check is the same as the normal check and can also be performed during the daily pre-startup check.

At the beginning of the normal inspection as shown in FIG. 13, the inspector rotates the rotating frame 45 fixed at the storage position downward, moves it to the inspection position and fixes it with the positioning pin 43 (process S21). The standard sample 30 is installed at the holding arm 452 of the rotating frame 45, so the standard sample 30 is also moved to the inspection position. Next, the V-notch 32 within the depth dimension standard is set to a measurement position that can be scanned by the laser displacement meter 11 (process S22). Specifically, at the holding arm 452, three holes are processed according to the screw hole 36, screw hole 37, and screw hole 38 of the substrate 35. The screw hole 36 in the center of the substrate 35 cooperates with the hole in the center of the holding arm 452, and the positioning screw is locked into the screw hole 36 from the bottom of the holding arm 452 through the hole of the holding arm 452, thereby positioning the standard sample 30. Furthermore, if the V-notch 32 has been set at the measured position, then in process S22, only the position of the V-notch 32 needs to be confirmed.

Next, the V-notch 32 is measured by the laser displacement meter 11 (process S23). At this time, it is not necessary to scan the entire length of the V-notch 32 of the standard sample 30, and it is sufficient to scan the portion necessary for data processing. After the scanning of the V-notch 32 is completed, the shape data acquisition unit 17 of the V-notch analysis computer 14 acquires the measurement value acquired by the laser displacement meter 11 (process S24). The evaluation data generation unit 18 generates evaluation data based on the acquired measurement value (process S25). The quality judgment unit 19 performs quality judgment of the V-notch 32 of the standard sample 30 based on the generated evaluation data (process S26). Because the depth dimension of the V-notch 32 is within the standard, the quality judgment unit 19 usually judges it as qualified. Therefore, the inspection operator confirms whether the quality judgment unit 19 judges it as qualified (process S27).

If it is determined to be qualified in process S27, the inspection operator determines that the V-notch evaluation device 1 is normal (process S28). If it is determined to be unqualified in process S27, the inspection operator determines that the V-notch evaluation device 1 is abnormal (process S29). Then, the inspection operator removes the positioning pin 43 that fixes the rotating frame 45, moves the rotating frame 45 to the storage position and fixes it with the positioning pin 43, and completes the inspection (process S30). And, if it is determined to be abnormal in process S29, the inspection operator confirms the cause of the abnormality of the V-notch evaluation device 1, for example: if dust is attached to the light receiving part 11B, clean the laser displacement meter 11, etc. After taking countermeasures for the abnormal cause, the normal inspection is performed again. After confirming that the V-notch evaluation device 1 is normal, the V-notch VN evaluation operation of the ingot SI can be carried out.

As shown in Figure 14, when the abnormal inspection begins, the inspector rotates the rotating frame 45 downward, moves it to the inspection position and fixes it with the positioning pin 43 (process S31). In addition, if the abnormal inspection is performed after the normal inspection, when the normal inspection is completed, the rotating frame 45 does not need to be returned to the storage position, and the inspection operation can be continued. Next, the V-notch 33 outside the depth dimension standard is set to the measurement position of the laser displacement meter 11 (process S32). Specifically, the screw hole 37 on the left side of the substrate 35 cooperates with the hole in the center of the holding arm 452, and the positioning screw is locked into the screw hole 37 from the bottom of the holding arm 452 through the hole of the holding arm 452, thereby positioning the standard sample 30.

Next, similar to processes S23 to S26 during normal inspection, the V-notch 33 is measured by the laser displacement meter 11 (process S33). After the scanning of the V-notch 33 is completed, the shape data acquisition unit 17 of the V-notch analysis computer 14 acquires the measurement value acquired by the laser displacement meter 11 (process S34). The evaluation data generation unit 18 generates evaluation data based on the acquired measurement value (process S35). In addition, because each V-notch 32, V-notch 33, and V-notch 34 is formed on an arc surface 31, the depth direction of the central V-notch 32 is perpendicular to the vertical direction of the bottom surface of the standard sample 30, but the depth directions of the left and right V-notches 33 and V-notch 34 are inclined relative to the direction perpendicular to the bottom surface of the standard sample 30. Therefore, when measuring the V-notch 33 and the V-notch 34, similar to the measurement of the V-notch VN, the evaluation data generating unit 18 performs rotational movement so that the processed surfaces of the V-notch 33 and the V-notch 34 face upward, and performs parallel movement so that the bottom of the processed surfaces of the V-notch 33 and the V-notch 34 is the origin, and generates evaluation data. The quality judgment unit 19 performs quality judgment of the V-notch 33 of the standard sample 30 based on the generated evaluation data (process S36). Next, the inspection operator confirms whether the quality judgment unit 19 judges it as qualified (process S37). The depth dimension of the V-notch 33 is smaller than the standard and is outside the standard, so the quality judgment unit 19 usually judges it as unqualified.

Therefore, if it is determined to be qualified in process S37, the inspection operator determines that the V-notch evaluation device 1 is abnormal (process S38). If it is determined to be unqualified in process S37, the inspection operator determines that the V-notch evaluation device 1 is operating normally (process S39). Next, the inspection operator confirms whether the inspection is completed (process S40). In the standard sample 30 of this embodiment, two V-notches 33 and V-notches 34 outside the standard are formed. Because the inspection of the V-notch 33 is to be carried out after the inspection of the V-notch 34, it is determined to be no in process S40, and the V-notch 34 outside the depth dimension standard is set to the inspection position of the laser displacement meter 11 (process S32). Specifically, the screw hole 38 on the right side of the base plate 35 matches the hole in the center of the retaining arm 452, and the positioning screw is locked into the screw hole 38 through the hole of the retaining arm 452 from the bottom of the retaining arm 452, thereby positioning the standard sample 30.

Then, the processing of process S33 to process S36 is executed again. Next, the inspection operator confirms whether the quality judgment unit 19 judges it as qualified (process S37). The depth dimension of the V-notch 33 is larger than the standard and is outside the standard, so the quality judgment unit 19 usually judges it as unqualified. Therefore, if it is judged as qualified in process S37, the inspection operator judges the V-notch evaluation device 1 as abnormal (process S38). If it is judged as unqualified in process S37, the inspection operator judges the V-notch evaluation device 1 as operating normally (process S39). Next, the inspection operator confirms whether the inspection is completed (process S40). If the inspection can be completed, it is judged as yes in process S40. The inspection operator removes the positioning pin 43 that fixes the rotating frame 45, moves the rotating frame 45 to the storage position and fixes it with the positioning pin 43 (process S41), and completes the inspection. In addition, if the V-notch 33 and V-notch 34 outside the standard are judged to be normal in process S39, the inspection operator confirms the abnormal cause of the V-notch evaluation device 1, takes countermeasures (such as cleaning the laser displacement meter 11, etc.), and then performs abnormal inspection again. After confirming that the V-notch evaluation device 1 is operating normally, the evaluation operation of the V-notch VN of the ingot SI can be performed.

According to the present embodiment as described above, the following effects are achieved. In the present embodiment, a standard sample 30 is prepared, which is cut out from a casting SI and processed with V-notches 32, 33, and 34 for inspection. Because the standard sample moving tool 40 fixed with the above-mentioned standard sample 30 is set in the V-notch evaluation device 1, when the V-notch evaluation device 1 is inspected, it is sufficient to rotate the rotating frame 45 of the standard sample moving tool 40 to the inspection position and fix it with the positioning pin 43, so that the V-notch evaluation device 1 can be easily inspected in a short time. In other words, another inspection method can be considered: a V-notch for inspection is processed on a grown semiconductor single crystal ingot SI to prepare a sample ingot, and the sample ingot is moved from the storage 2 to the V-notch evaluation device 1. However, in the above method, it is necessary to ensure a storage place for the sample ingot, because it is moved from the storage 2 to the position measured by the V-notch evaluation device 1, and it is necessary to return to the storage 2 after inspection, which increases the working hours. In contrast, in this embodiment, the standard sample 30 is minimized to a size that can be attached to the V-notch evaluation device 1. Because the rotating frame 45 is fixed to the standard sample moving tool 40, the operation time for moving the standard sample 30 to the inspection position can also be reduced to a minimum, which can improve the inspection operation efficiency.

In this embodiment, a plurality of V-notches are formed on the standard sample 30: a normal determination V-notch 32 whose depth dimension is within the standard, and an abnormal determination V-notch 33 and V-notch 34 whose depth dimension is outside the standard. Therefore, a normal inspection and an abnormal inspection can be performed using one standard sample 30. The normal inspection is to check whether the normal determination V-notch 32 can be correctly judged as normal, and the abnormal inspection is to check whether the abnormal determination V-notch 33 and V-notch 34 can be correctly judged as abnormal. The measurement accuracy of the V-notch evaluation device 1 can be easily maintained and managed.

In this embodiment, the standard sample moving tool 40 is composed of a support 41 and a rotating frame 45 on which the standard sample 30 is mounted. The inspection operation for measuring the accuracy can be performed by simply rotating the rotating frame 45 90 degrees from the storage position to the inspection position and fixing it with the positioning pin 43, so the inspection operation can be started with the minimum man-hours. In addition, if the rotating frame 45 is rotated 90 degrees from the inspection position to the storage position and fixed with the positioning pin 43, the standard sample moving tool 40 and the standard sample 30 can be prevented from interfering with the ingot SI when the V-notch VN of the ingot SI is measured thereafter, and the transition from the inspection operation to the normal evaluation operation can also be achieved with the minimum man-hours.

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 the shape data of the V-notch VN processing surface of the entire length of the V-notch VN can be obtained. Therefore, by transforming the obtained shape data of the V-notch VN processing surface into coordinates and generating evaluation data, the overall evaluation of the V-notch VN can be performed, and the quality of the V-notch VN can be determined with high precision. Furthermore, during inspection, the data of the V-notch 32, V-notch 33, and V-notch 34 of the standard sample 30 measured by the laser displacement meter 11 are used, processed, and judged by the shape data acquisition unit 17, the evaluation data generation unit 18, and the quality judgment unit 19 that process the measurement data of the V-notch VN of the ingot SI. Therefore, not only the defects of the laser displacement meter 11 but also the defects of the shape data acquisition unit 17, the evaluation data generation unit 18, and the quality judgment unit 19 can be judged. Therefore, when the program is updated due to system improvement, etc., it is possible to check whether each V-notch 32, V-notch 33, and V-notch 34 of the standard sample 30 can be correctly judged, and errors in the inspection program can be detected.

Since the standard sample 30 is made of a block cut out from a silicon single crystal ingot SI, it can be a silicon standard sample 30 with a stable shape and can be used as a standard sample 30 for a long time. In addition, the shape of the V-notch processed by a grindstone can be reproduced, and the V-notch 32 with a depth dimension within the standard and the V-notches 33 and 34 with depth dimensions outside the standard can be easily formed.

In this embodiment, the V-notch evaluation method of the ingot SI is used to determine the quality of the V-notch VN of the ingot SI subjected to the V-notch processing, thereby eliminating the ingots with defects in the V-notch VN. Therefore, in the cutting process as the next process, defective products caused by the defects of the V-notch VN can be eliminated, so that unnecessary processing in the cutting process can be reduced. In this embodiment, an air supply mechanism 13 is provided in front of the scanning direction of the laser displacement meter 11. Therefore, after the V-notch VN of the ingot SI is processed, the dust and cutting fluid attached to the V-notch VN can be removed, so the laser displacement meter 11 can scan in a clean state, which can improve the measurement accuracy of the V-notch shape.

[Varied Embodiments] Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific structure is not limited to the above-mentioned embodiments, and various improvements and design changes are also included in the present invention without departing from the scope of the present invention. As a standard sample, it is not limited to the same material as the single crystal ingot for semiconductors such as silicon, but can also be a metal such as stainless steel and a synthetic resin material, which can form V-notches 32, V-notches 33, and V-notches 34, and can be measured by the laser displacement meter 11. The shape of the standard sample is not limited to the above-mentioned embodiments. For example, a standard sample 30B shown in Figure 15 can also be used. The standard sample 30B is formed with three arc surfaces 31 having the same curvature as the outer peripheral surface of the ingot SI, and each arc surface 31 is formed with a V-notch 32, a V-notch 33, and a V-notch 34 at the vertex. According to this standard sample 30B, when sliding on the holding arm 452 to move each V-notch 32, a V-notch 33, and a V-notch 34 to the measurement position directly below the laser displacement meter 11, the direction of each V-notch 32, a V-notch 33, and a V-notch 34 can be fixed.

The number of V-notches formed in the standard sample is not limited to three. For example, in the standard sample, one V-notch within the standard may be provided, or two or more than four V-notches may be provided. In addition, the depth dimension of the V-notch formed in the standard sample is not limited to within the specification or outside the specification, and can be set based on the index for evaluating the V-notch. For example, in addition to the depth dimension, if 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 are used as evaluation indexes, standard samples with V-notches within the standard and V-notches outside the standard formed with each index may also be used. In this case, different standard samples may be prepared for each index, and replaced and mounted on the retaining arm 452. A plurality of rotating frames 45 may also be provided, and different standard samples may be installed on each rotating frame 45, and the plurality of rotating frames 45 may be moved to the inspection position in sequence for inspection.

Although the standard sample 30 moves in the horizontal direction relative to the holding arm 452, when the standard sample 30 moves in the arc direction relative to the holding arm 452 and each V-notch 33, V-notch 34 is moved to the measurement position, the opening direction of the V-notch 33, V-notch 34 can be set to be oriented in the same vertical direction as the V-notch 32.

The standard sample moving tool is not limited to the structure of the aforementioned embodiment. For example, it can also be composed of a holding table for holding the standard sample 30 and a moving device for sliding the holding table to an inspection position and a storage position.

1: V-notch evaluation device 2: Storage area 3: Outgoing workstation 4: Carrying out device 5: Operation system 6: Holding frame 7A: Grinder 7B: Grinder 7C: Grinder 7D: Grinder 8: Long station 11: Laser displacement meter 11A: Light-emitting unit 11B: Light-receiving unit 11C: Measurement value output cable 12: Frame 13: Air supply mechanism 14: V-notch analysis computer 15: Calculation processing device 16: Memory device 17: Shape data acquisition unit 18: Evaluation data generation unit 19: Good or bad judgment unit 20: 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 36: Screw hole 37: Screw hole 38: Screw hole 40: Standard sample moving tool 41: Pillar 411: Pillar body 412: Bracket 413: Support plate 4131: First support plate 4132: Second support plate 414: First through hole 415: Second through hole 416: Through hole 417: Joint plate 42: Shoulder screw 43: Positioning pin 45: Rotating frame 451: Rotating arm 4511: Locking surface 4512: Long hole 4513: Hole 4514: Hole 452: Holding arm 4521: holding sheet S1: process S2: process S3: process S4: process S5: process S6: process S7: process S8: process S9: process S10: process S11: process S12: process S13: process S14: process S21: process S22: process S23: process S24: process S25: process S26: process S27: process S28: process S29: process S30: process S31: process S32: process S33: process S34: process S35: process S36: process S37: process S38: process S39: process S40: process S41: process SI: Ingot VN: V-notch

FIG. 1 is a schematic diagram showing the structure of a processing device for semiconductor single crystal ingots according to an embodiment of the present invention, wherein the processing device includes a V-notch evaluation device. FIG. 2 is a schematic diagram showing the configuration of the aforementioned V-notch evaluation device and the processing device. FIG. 3 is a schematic diagram showing the structure of an optical measurement tool in the aforementioned V-notch evaluation device. FIG. 4 is a functional block diagram showing the structure of a data processing tool in the aforementioned V-notch evaluation device. FIG. 5 is a graph showing shape data of a V-notch scanned by the aforementioned optical measurement tool. FIG. 6 is a graph showing evaluation data generated by an evaluation data generation unit in the aforementioned V-notch evaluation device. FIG. 7 is a diagram showing a standard sample set in the aforementioned V-notch evaluation device, wherein (A) is a top view and (B) is a side view. FIG. 8 is a front view showing a state in which a standard sample moving tool holding a standard sample is moved to an inspection position in the aforementioned V-notch evaluation device. FIG. 9 is a side view showing a state in which a standard sample moving tool holding a standard sample is moved to an inspection position in the aforementioned V-notch evaluation device. FIG. 10 is a front view showing the aforementioned standard sample moving tool being moved to a storage position. FIG. 11 is a side view showing the aforementioned standard sample moving tool being moved to a storage position. FIG. 12 is a flow chart showing a V-notch processing method in the aforementioned embodiment. FIG. 13 is a flow chart showing a normal inspection method of the V-notch evaluation device in the aforementioned embodiment. FIG. 14 is a flow chart showing an abnormal inspection method of the V-notch evaluation device in the aforementioned embodiment. Figure 15 is a diagram showing a modified embodiment of the standard sample set in the aforementioned V-notch evaluation device.

11: Laser displacement meter 12: Frame 30: Standard sample 32: V notch 33: V notch 34: V notch 35: Substrate 40: Standard sample moving tool 41: Pillar 411: Pillar body 412: Bracket 413: Support plate 417: Joint plate 42: Shoulder screw 43: Positioning pin 45: Rotating frame 451: Rotating arm 452: Holding arm 4521: Holding sheet

Claims (6)

A V-notch evaluation device for an ingot is used to evaluate the V-notch formed in the longitudinal direction of a single crystal ingot for semiconductors, comprising: an optical measuring tool, comprising a light-emitting part and a light-receiving part, for scanning the shape of the V-notch; a moving tool, for relatively moving the ingot or the optical measuring tool in the longitudinal direction of the ingot; a data processing tool, for processing the V-notch shape data obtained by scanning the optical measuring tool; and a standard sample moving tool, for holding a standard sample formed with a V-notch for inspection, and for moving 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 measuring tool; wherein the storage position is a position that does not interfere with the ingot moved by the moving tool. A V-notch evaluation device for a casting ingot as claimed in claim 1, wherein the standard sample is formed with a plurality of V-notches. A V-notch evaluation device for a casting as claimed in claim 2, wherein the plurality of V-notches include a V-notch for normal determination and a V-notch for abnormal determination. As in claim 1, the V-notch evaluation device for casting ingots, wherein the standard sample moving tool is constructed to include a support and a rotating frame, the rotating frame is configured to be rotatable relative to the support, can be moved to the inspection position and the storage position, and hold the standard sample; wherein the rotating frame is configured to be fixed to the support at the inspection position and the storage position respectively. A V-notch evaluation device for a cast ingot as claimed in claim 1, wherein the standard sample moving tool is constructed to include a holding table and a moving device, the holding table holds the standard sample, and the moving device slides the holding table to the inspection position and the storage position. The V-notch evaluation device for castings as claimed in claim 1, wherein the data processing tool comprises: a shape data acquisition unit, which acquires the V-notch shape data measured by the optical measurement tool; an evaluation data generation unit, which performs coordinate transformation of the acquired V-notch shape data to generate evaluation data for evaluating the V-notch shape; and a quality judgment unit, which judges the quality of the V-notch shape based on the generated evaluation data.

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