Wafer position search device, position search method, and wafer speed calculation method

Abstract

The present invention discloses a wafer position search device, wherein the wafer is in a rotated state and a notch is provided on its outer edge; the position search device includes a signal transmission mechanism that transmits a signal in at least the direction in which the wafer is located, wherein the signal can pass through the notch and is blocked when the signal passes through the wafer; and a signal reception mechanism that receives the signal transmitted by the signal transmission mechanism and determines whether the notch passes through a signal transmission path or determines the number of times the notch passes through a signal transmission path. The present invention also discloses a wafer position search method. The present invention further discloses a method for calculating wafer rotation speed. The present invention can determine the wafer notch position by determining the wafer position, improves the reliability of wafer pickup and placement during the process, saves equipment space, and improves the reliability of wafer rotation speed detection.

Description

Technology Field

[0001] The present invention belongs to the field of semiconductor integrated circuit chip manufacturing, and in particular relates to a wafer position search device, a position search method, and a wafer speed calculation method. Background Technology

[0002] Chemical mechanical planarization is a processing step in integrated circuit manufacturing. As technology advances, the requirements for processing steps increase accordingly. At the same time, chemical mechanical planarization is a wet process in wafer processing, and since large amounts of polishing fluid and various chemical reagents are used throughout the process, the wafer must be washed and dried at the end of the process to remove particles attached to the wafer surface before it can enter the next manufacturing process.

[0003] Since 8-inch and 12-inch wafers are positioned in a small notch shape, the notch width is 1.5 to 3 mm and the depth is 1 to 2 mm. As shown in FIG. 14, L1 is 1.5 to 3 mm and L2 is 1 to 2 mm. Because the notch is small, it does not affect the grab, transfer, and positioning of the mechanism, so there is no need for notch location search. However, the positioning notch of a 6-inch wafer takes the form of a flat plane with a plane width of 57.5 mm, meaning the total notch area is relatively large. Adding existing tooling causes the wafer to separate, which seriously affects the safety and reliability of the process flow. Therefore, it is necessary to locate the 6-inch wafer notch plane and determine its position to ensure that it is not affected during the grab process.

[0004] Since the position of the notch used for wafer positioning after cleaning cannot be accurately determined, the requirements for positioning the clamping mechanism of the subsequent drying process device are very high, increasing the complexity of the mechanism and reducing reliability. To improve the reliability of wafer grab transfer and fixation and to achieve accurate recording of wafer rotation speed, the wafer position search and speed calculation methods need to be further improved. The problem to be solved

[0005] To overcome the shortcomings of conventional technology, the present invention provides a wafer position search device, a wafer position search method, and a wafer speed calculation method, wherein the notch portion is located directly above the wafer when the wafer rotation stops, the wafer rotation speed can be accurately calculated, and the device structure is simple. means of solving the problem

[0006] The technical solution means used by the present invention to solve the technical problem is a wafer position search device, wherein the wafer is in a rotated state and a notch is provided on its outer edge; and the position search device is at least,

[0007] A signal transmission mechanism that transmits a signal in the direction in which a wafer is located, wherein the signal can pass through a notch and is blocked by the signal when it passes through the wafer; and

[0008] It includes a signal receiving mechanism that receives a signal transmitted by a signal transmitting mechanism and determines whether the notch passes through the signal transmission path, or determines the number of times the notch passes through the signal transmission path.

[0009] Furthermore, the above notch is formed by horizontally cutting the edge of the wafer.

[0010] Furthermore, if the above signal completely passes through the notch, and the vertical distance from the signal to the plane of the notch is h, then 0 < h ≤ 5 mm.

[0011] Furthermore, the signal transmission mechanism and the signal reception mechanism are located on the same side of the wafer; or, the signal transmission mechanism and the signal reception mechanism are located on both sides of the wafer; or, the signal transmission mechanism and the signal reception mechanism are an integrated structure.

[0012] Furthermore, the signal transmission mechanism is a laser generator, the signal reception mechanism is a laser receiver, and the signal is a strip laser.

[0013] Furthermore, the above-mentioned position finding device further includes a reflector, the signal transmission mechanism is a transmissive laser generator, and the signal reception mechanism is a transmissive laser receiver;

[0014] The above-mentioned position finding device further includes a reflector, and the signal transmission mechanism and signal reception mechanism are retroreflective laser generators.

[0015] Furthermore, a transparent cover is installed outside the signal transmission mechanism and the signal reception mechanism.

[0016] Furthermore, it includes a signal processing mechanism that is interconnected with the signal transmission mechanism and the signal reception mechanism.

[0017] The present invention also discloses a wafer position search method, and

[0018] A step of determining a signal strength threshold when a signal transmitted by a signal transmission mechanism completely passes through a notch;

[0019] A step of operating a signal transmission mechanism and a signal reception mechanism to cause the wafer to rotate under the drive of a driving mechanism;

[0020] The wafer performs a first deceleration rotation until at least a portion of the next signal enters the notch;

[0021] A step in which the signal receiving mechanism begins to receive a signal, and the wafer performs a second deceleration rotation; and

[0022] The method includes the step of the signal receiving mechanism receiving signals of progressively greater intensity until it receives a signal of maximum intensity, and the signal processing mechanism transmitting a rotation stop signal to the driving mechanism;

[0023] The wafer stops rotating, and at this point, the plane of the notch faces upward.

[0024] Furthermore, the wafer rotates under the drive of the support wheel drive mechanism of the scrubbing device. Conventional wafer scrubbing devices can ensure that the wafer surface is perfectly cleaned through the cooperation of a support wheel system and a roller brush system, but the wafer cannot stop at a fixed position after scrubbing, and the position of the notch used for positioning on the wafer cannot be accurately determined; at the same time, in conventional scrubbing devices, the support wheel system within the box body is generally composed of two drive wheels and one non-powered idler wheel, and the wafer obtains rotational speed during the scrubbing process by driving the idler wheel; however, in the above solution, sliding friction occurs between the wafer and the idler wheel surface, affecting the transmission precision, so the actual rotational speed of the wafer cannot be accurately obtained. The above problems can be overcome by using the position search method and speed calculation method of the present invention, improving the reliability of the transition to the grab after the wafer cleaning process and achieving an accurate recording of the wafer's rotational speed.

[0025] Furthermore, the above notch is formed by horizontally cutting the edge of the wafer, and when the signal completely passes through the notch, if the vertical distance from the signal to the plane of the notch is h, then 0 < h ≤ 5 mm.

[0026] The present invention further discloses a method for calculating wafer rotation speed, said method, said method,

[0027] A step of operating a signal transmission mechanism and a signal reception mechanism to cause the wafer to rotate under the drive of a driving mechanism;

[0028] When the signal passes through the notch, the signal receiving mechanism transmits the received signal to the signal processing mechanism to start timing;

[0029] When the signal passes the notch portion in the next pass, the signal processing mechanism reads the interval duration to obtain the wafer rotation speed;

[0030] Alternatively, when the signal passes through the notch multiple times, the signal processing mechanism includes the step of reading the interval duration and obtaining the wafer rotation speed through the total duration and the number of passes. Effects of the invention

[0031] The beneficial effects of the present invention are that by implementing wafer positioning, the wafer notch position can be determined, thereby achieving a high level of process control and solving the problem of 6-inch wafer notch positioning; significantly improving the reliability of wafer pickup and placement during the process and saving equipment space; since the drying process requires high control over the wafer notch position, the wafer notch position must be fixed before entering the drying unit, and since the notch position is determined and aligned directly in the scrubbing unit through the cooperation of a position finding device and a support wheel drive mechanism after scrubbing is completed, the claw can directly lift the wafer vertically without unnecessary movements. By integrating the positioning function into the previous process, the requirements of the next process are perfectly met without interfering with or increasing the previous scrubbing process, the idea is novel, and space and time costs are saved; and it can be applied to 6-inch, 8-inch, and 12-inch wafers. Since the positioning signal is transmitted only once without being blocked during the 360° rotation of the wafer (the distance sensor detects different distance value signals), the accuracy of the wafer rotation speed measurement is higher than the speed calculation of the idler wheel, thereby improving the reliability of wafer rotation speed detection. Brief explanation of the drawing

[0032] FIG. 1 is a front view of a wafer of the present invention. FIG. 2 is a perspective view of the scrubbing device of the present invention. FIG. 3 is a front view of the scrubbing device of the present invention. Figure 4 is a cross-sectional view of the BB in Figure 3 where the wafer is not placed. Figure 5 is a cross-sectional view of the BB of Figure 3, and the placed wafer notch is not located directly above, and the wafer blocks the signal. FIG. 6 is a cross-sectional view of the BB of FIG. 3, and the placed wafer notch is located directly above. FIG. 7 is a side view of the scrubbing device of the present invention. Figure 8 is a cross-sectional view of the CC section of Figure 7. Figure 9 is an enlarged view of the structure of part a of Figure 8. Figure 10 is a schematic diagram of a wafer rotating until some signals are blocked. FIG. 11 is a schematic diagram showing the signal transmission mechanism and the signal reception mechanism of the present invention located on different sides. FIG. 12 is a schematic diagram in which the signal transmission mechanism and the signal reception mechanism of the present invention are located on the same side. FIG. 13 is an operational schematic diagram in which the signal transmission mechanism of the present invention is a transmissive laser generator and the signal reception mechanism is a transmissive laser receiver. Figure 14 is a schematic diagram of a small notch on a conventional 8-inch wafer. Specific details for implementing the invention

[0033] To enable those skilled in the art to better understand the means of solution of the present invention, the technical means of solution according to the embodiments of the present invention are described below in conjunction with the attached drawings according to embodiments of the present invention, but it is clear that the described embodiments are only some embodiments of the present invention and not all embodiments. All other embodiments obtained by those skilled in the art without inventive effort based on the embodiments of the present invention shall be deemed to fall within the scope of protection of the present invention.

[0034] As a wafer position search device, the wafer (1) is in a rotated state and a notch (11) is provided on its outer edge, and the notch (11) is formed by horizontally cutting the edge of the wafer (1), that is, it has a flat surface, and as shown in FIG. 1, the flat width s of the notch (11) is 57.5 mm.

[0035] As illustrated in FIGS. 3 to 10, the location search device includes at least a signal transmission mechanism (2) and a signal reception mechanism (3).

[0036] The signal transmission mechanism (2) transmits a signal in the direction where the wafer (1) is located, and the signal can pass through the notch portion (11), and when the signal passes through the wafer (1), it is blocked by the wafer (1) and cannot pass through.

[0037] The signal receiving mechanism (3) receives a signal transmitted by the signal transmitting mechanism (2) and determines whether the notch portion (11) passes through the signal transmission path, or determines the number of times the notch portion (11) passes through the signal transmission path. In other words, if the signal passes through the notch portion (11), the signal receiving mechanism (3) receives the signal, and if the signal is blocked by the wafer (1), the signal receiving mechanism (3) cannot receive the signal.

[0038] In order to ensure that the signal has sufficient strength after passing through the notch (11), when the signal completely passes through the notch (11), if the vertical distance from the signal to the plane of the notch (11) is h, then 0 < h ≤ 5 mm, as specifically illustrated in FIG. 9.

[0039] When the notch (11) faces directly upward, the entire signal is received by the signal receiving mechanism (3), resulting in a high signal strength; after the wafer (1) is rotated at a certain angle, a portion of the signal is blocked, and the signal strength weakens. The accuracy of the wafer notch (11) position can be improved by adjusting the signal threshold of the signal receiving mechanism (3). That is, the higher the signal reception strength, the more signals are received, making the notch (11) position more horizontally flat, and the direction of the notch (11) becomes closer to the horizontally upward; the weaker the signal, the lower the horizontal flatness of the notch (11) position. In actual applications, the signal threshold of the signal receiving mechanism (3) can be adjusted according to the requirements for horizontal flatness of the process notch position, that is, the requirements for accuracy of the notch (11) position. Additionally, the sensitivity of detection can be affected by adjusting the distance between the signal receiving mechanism (3), the signal transmitting mechanism (2), and the notch (11), and the sensitivity increases as the distance becomes closer.

[0040] The signal transmission mechanism (2) and the signal reception mechanism (3) are located on both sides of the wafer (1), and as shown in FIG. 11, in this case, the signal transmission mechanism (2) is a laser generator and the signal reception mechanism (3) is a laser receiver, and the signal (6) may be a strip laser and additionally include a corresponding signal processing mechanism. Of course, in other embodiments, the signal may be a point-shaped laser, and in this case, whether the signal passes through the notch (11) is determined through the appearance and disappearance of the laser. Of course, the signal may be any other shape such as an optical fiber or ultrasound, and is not specifically limited.

[0041] The signal transmission mechanism (2) and the signal reception mechanism (3) may be an integrated structure, and as shown in FIG. 12, in this case, the signal transmission mechanism (2) and the signal reception mechanism (3) are retroreflective laser generators, and the position finding device further includes a reflector (4) and a corresponding signal processing mechanism. After the signal is transmitted from the retroreflective laser generator, the reflector (4) reflects the signal back to the retroreflective laser generator.

[0042] The signal transmission mechanism (2) and the signal reception mechanism (3) are located on the same side of the wafer (1), and as shown in FIG. 13, in this case, the signal transmission mechanism (2) is a transmissive laser generator and the signal reception mechanism (3) is a transmissive laser receiver, and the signal (6) may be a strip laser, and the position finding device further includes a reflector (4) and a corresponding signal processing mechanism, which are connected to the signal transmission mechanism (2) and the signal reception mechanism (3), respectively. After the signal is transmitted from the transmissive laser generator, the reflector (4) reflects the signal to the transmissive laser receiver.

[0043] As shown in FIG. 2, a transparent cover (7) is installed on the outside of the signal transmission mechanism (2) and the signal reception mechanism (3) to form a good protective effect, prevent contamination of the liquid during the scrubbing process, and ensure that light does not affect the transmission and reception of the signal.

[0044] The signal transmission mechanism (2) and the signal reception mechanism (3) may be placed within an area corresponding to the inscribed circle of the notch portion (11) of the wafer (1) or the concentric circle of the wafer excluding the notch portion, and the wafer (1) is determined to be accurately aligned through whether the signal reception mechanism (3) has received a signal. As shown in FIG. 6, when the wafer (1) rotates around the center of the circle, the laser signal is always blocked, and the signal reception mechanism (3) cannot receive a signal indicating that the wafer (1) is present.

[0045] A wafer location search method includes the following steps.

[0046] A signal strength threshold is determined when the signal transmitted by the signal transmission mechanism (2) completely passes through the notch (11); wherein, the signal completely passing through means that there is no part blocked by the wafer (1) in the signal cross-section.

[0047] The signal transmission mechanism (2) and the signal reception mechanism (3) are operated to cause the wafer (1) to rotate under the drive of the drive mechanism. In this embodiment, the drive mechanism is the support wheel drive mechanism of the scrubbing device (5), and of course, in other embodiments, the drive mechanism may be the support wheel drive mechanism of the ultrasonic cleaning device or a drive mechanism within another box body related to cleaning; since the drive mechanism driving the rotation of the wafer (1) can be implemented in the prior art, it is not described again.

[0048] After the wafer (1) scrubbing is completed, the driving mechanism drives the wafer (1) to perform a first deceleration rotation, and the wafer (1) continues to rotate at a relatively slow speed until at least a portion of the signal transmitted by the signal transmission mechanism (2) in the next rotation enters the notch (11), that is, until the signal begins to enter the notch (11).

[0049] The signal receiving mechanism (3) begins to receive the signal, and the signal gradually increases from weak to strong, at which time the wafer (1) performs a second deceleration rotation, where the rotation after the second reduction may be constant speed rotation or the rotation speed may gradually decrease.

[0050] The signal strength received by the signal receiving mechanism (3) gradually increases until a signal of maximum strength is received, which means that the signal strength received by the signal receiving mechanism (3) is equal to a initially predetermined signal strength threshold, that is, that the signal completely passes through the notch (11), and the signal processing mechanism transmits a rotation stop signal to the driving mechanism, and of course, the signal transmission between the previous signal transmitting mechanism (2) and the signal receiving mechanism (3) is also obtained by the signal processing mechanism, and since these functions can be implemented in the prior art, they are not described again.

[0051] The wafer (1) momentarily stops rotating, and the plane of the notch (11) faces directly upward, that is, the plane of the notch (11) is parallel to the horizontal plane.

[0052] The method for calculating wafer rotation speed is,

[0053] A step of operating the signal transmission mechanism (2) and the signal reception mechanism (3) so that the wafer (1) rotates under the driving of the driving mechanism;

[0054] When the signal passes through the notch (11), specifically at the moment it has completely passed through, the signal receiving mechanism (3) transmits the received signal to the signal processing mechanism to start the timing;

[0055] When the signal passes through the notch (11) in the next pass, specifically at the moment it completely passes, the signal processing mechanism reads the duration of the interval between the two signals to obtain the rotation speed of the wafer (1);

[0056] Alternatively, when the signal passes through the notch (11) in the next pass, specifically at the moment it has completely passed, the signal processing mechanism reads the interval duration between the two signals, and then when the signal passes through the notch (11) again, the signal processing mechanism reads the interval duration between the second and third passes, and repeats the above steps, and when the signal passes through the notch (11) multiple times, the signal processing mechanism reads the interval duration multiple times and includes the step of calculating the rotation speed of the wafer (1) through the average duration.

[0057] Of course, when the signal passes through the notch (11) multiple times, the signal processing mechanism may also calculate the rotation speed of the wafer (1) through the total duration and the total number of times the signal passes.

[0058] The specific embodiments described above are intended to illustrate the invention and not to limit it, and any modifications and changes made to the invention within the spirit of the invention and the scope of the claims are all included within the scope of protection of the invention.

Claims

Claim 1 A wafer position search method comprising: determining a signal strength threshold when a signal transmitted by a signal transmission mechanism completely passes through a notch portion of a wafer; operating a signal transmission mechanism and a signal reception mechanism and causing the wafer to rotate under the drive of a drive mechanism; performing a first deceleration rotation with respect to the wafer until at least a portion of the next signal enters the notch portion; and performing a second deceleration rotation with respect to the wafer when the signal reception mechanism begins to receive a signal. A wafer position search method characterized in that, when the signal receiving mechanism receives a signal of increasingly greater intensity and receives a signal of the signal intensity threshold, the signal processing mechanism transmits a rotation stop signal to the driving mechanism, wherein the wafer stops rotating, at which time the plane of the notch portion is positioned parallel to the horizontal plane, the notch portion is formed by horizontally cutting the edge of the wafer, the signal is a band-shaped signal, and the band-shaped signal is transmitted along a plane parallel to the horizontal plane, the signal receiving mechanism receives a signal of different intensity depending on the degree to which the band-shaped signal passes through the notch portion, and the signal of the signal intensity threshold is a signal of maximum intensity received when the band-shaped signal completely passes through the notch portion. Claim 2 A wafer position search method according to claim 1, characterized in that the wafer rotates under the drive of a support wheel drive mechanism of a scrubbing device. Claim 3 A wafer position search method according to claim 1, characterized in that when the signal completely passes through the notch, if the vertical distance from the signal to the plane of the notch is h, then 0 < h ≤ 5 mm. Claim 4 A wafer position search method according to claim 1, wherein the signal transmission mechanism and the signal reception mechanism are located on the same side of the wafer; or, the signal transmission mechanism and the signal reception mechanism are located on both sides of the wafer; or, the signal transmission mechanism and the signal reception mechanism are an integrated structure. Claim 5 A wafer position search method according to claim 1, wherein the signal transmission mechanism is a laser generator, the signal reception mechanism is a laser receiver, and the signal is a strip laser. Claim 6 A wafer position search method according to claim 1, characterized in that a transparent cover is installed outside the signal transmission mechanism and the signal reception mechanism. Claim 7 delete Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 delete

Images