WAFER LAPPING DEVICE AND CONTROL METHOD FOR IT

Abstract

A wafer lapping device can include a bottom plate, an upper plate positioned on the bottom plate in conjunction with the bottom plate to lap a wafer, a cylinder configured to move the upper plate up and down via a rod, a detection target element configured to descend along with the upper plate, multiple position sensors configured to detect the detection target element descending along with the upper plate to detect a lowering position of the upper plate, a displacement sensor configured to detect the detection target element descending along with the upper plate to detect a lowering displacement of the upper plate, and a controller configured to control a lowering speed of the upper plate based on the lowering displacement of the upper plate and the lowering position of the upper plate.

Description

Wafer lapping device and its control method

[0001] The present invention relates to a wafer wrapping device and a method for controlling the same.

[0002] In general, a wafer is a single-crystal silicon thin plate made from polycrystalline silicon as a raw material, and is widely used as a material for manufacturing semiconductor devices.

[0003] These wafers are manufactured by growing polycrystalline silicon into a single-crystal silicon ingot, then going through a slicing process to cut the silicon ingot into the shape of a wafer, a lapping process to even out the thickness of the wafer and make it flat, an etching process to remove or alleviate damage caused by mechanical polishing, a polishing process to make the wafer surface smooth, and a cleaning process to clean the wafer.

[0004] Among these, the lapping process is a process in which the wafer is pressed between the upper and lower plates, slurry is injected between the wafer and the upper / lower plates, and the upper / lower plates are rotated so that the wafer rotates and revolves and is wrapped by the slurry.

[0005] Typically, the upper platen descends and contacts the lower platen, and then the upper and lower plates rotate to polish the wafer. Since the upper and lower plates rotate at high speeds, the upper and lower plates must rotate after the upper platen contacts the lower platen to prevent the wipe-out phenomenon, in which the wafer is detached from the carrier.

[0006] Traditionally, the lower and upper stages rotate according to the descent time set in the recipe. However, the actual descent time of the upper stage varies with each run due to environmental or internal issues. Consequently, the descent time set in the recipe may differ from the actual descent time of the upper stage. In other words, the actual descent time of the upper stage may be greater or less than the descent time set in the recipe.

[0007] If the actual descent time of the upper platen is longer than the descent time specified in the recipe, this means the upper platen is lowered too late. In this case, the upper and lower plates rotate without the upper platen touching the lower platen, causing a wipe-out phenomenon in which wafers contained in multiple carriers are detached. This wipe-out phenomenon can cause collisions between the wafers and carriers, potentially damaging both. Furthermore, replacing the carriers and cleaning the platen requires significant time.

[0008] If the actual descent time of the upper plate is shorter than the descent time specified in the recipe, it means the upper plate is descending too quickly. This can lead to the rapid descent of the upper plate, potentially colliding with the wafer, potentially damaging it. If these damaged wafers are not addressed and the polishing process continues, the wafer fragments can scratch or damage the polishing surfaces of other wafers, potentially damaging surrounding components or equipment.

[0009] Therefore, there is an urgent need for a device or method that can precisely and efficiently control the lowering speed of the upper plate to prevent wipe-out of the wafer and damage to the wafer.

[0010] The present invention aims to solve the above-mentioned and other problems.

[0011] Another object of the embodiment is to provide a wafer lapping device and a control method thereof capable of preventing wipe-out of a wafer.

[0012] Another object of the present invention is to provide a wafer lapping device and a control method thereof capable of preventing wafer breakage.

[0013] The technical problems of the embodiment are not limited to those described in this article, but include those that can be understood through the description of the invention.

[0014] According to a first aspect of the embodiment to achieve the above or other purposes, a wafer lapping device includes: a lower platen; an upper platen disposed on the lower platen and engaging with the lower platen to wrap a wafer; a cylinder moving the upper platen up and down via a rod; a detection target member that descends together with the upper platen; a plurality of position sensors that detect the detection target member that descends together with the upper platen to detect a descending position of the upper platen; a displacement sensor that detects the detection target member that descends together with the upper platen to detect a descending displacement of the upper platen; and a control unit that controls a descending speed of the upper platen based on the descending displacement of the upper platen and the descending position of the upper platen.

[0015] The descending speed of the upper plate may include a specific speed of the upper plate in a specific section. The specific section may be a section between a first position at which the lower side of the upper plate is located when the detection target is located at the lowest position sensor among the plurality of position sensors and a second position at which the lower side of the upper plate is located when the upper plate touches the lower plate.

[0016] The above control unit can determine the point at which the displacement signal detected from the displacement sensor is inflected as the second position.

[0017] The control unit may obtain the falling time of the upper plate based on the falling displacement of the upper plate and the falling position of the upper plate in the specific section, obtain whether the falling time of the upper plate is within a set range, and if the falling time of the upper plate is outside the set range, adjust the weight value so that the falling time of the upper plate is within the set range.

[0018] The above control unit may increase the weight value to reduce a specific speed of the upper plate in the specific section when the falling time of the upper plate is less than the lower limit of the set range.

[0019] The control unit may decrease the weight value to increase a specific speed of the upper plate in the specific section when the falling time of the upper plate exceeds the upper limit of the set range.

[0020] The above plurality of position sensors can be installed along a vertical direction on one side of the cylinder.

[0021] The displacement sensor may be positioned higher than the uppermost position sensor among the plurality of position sensors and may be installed between the cylinder and the uppermost position sensor.

[0022] The wafer wrapping device may include a support to which the plurality of position sensors and the displacement sensor are fixedly connected.

[0023] The support may include a first support portion that securely fastens a plurality of position sensors installed along the vertical direction; and a second support portion that extends from the upper side of the first support portion toward the cylinder and to which the displacement sensor is securely fastened.

[0024] The above detection target portion can be moved up and down between each of the plurality of position sensors and the cylinder.

[0025] According to a second aspect of the embodiment to achieve the above or other purposes, a control method of a wafer lapping device includes a lower platen, an upper platen positioned on the lower platen and engaging with the lower platen to wrap a wafer, and a cylinder moving the upper platen up and down via a rod, the control method comprising: a step of detecting a detection target part descending together with the upper platen to detect a lowering position of the upper platen by the plurality of position sensors; a step of detecting a detection target part descending together with the upper platen to detect a lowering displacement of the upper platen by the displacement sensor; and a step of controlling a lowering speed of the upper platen based on the lowering displacement of the upper platen and the lowering position of the upper platen.

[0026] The descending speed of the upper plate may include a specific speed of the upper plate in a specific section. The specific section may be a section between a first position at which the lower side of the upper plate is located when the detection target is located at the lowest position sensor among the plurality of position sensors and a second position at which the lower side of the upper plate is located when the upper plate touches the lower plate.

[0027] A method for controlling a wafer wrapping device may include a step of determining a point at which a displacement signal detected from the displacement sensor is inflected as the second position.

[0028] A control method of a wafer lapping device may include: a step of obtaining a falling time of the upper plate based on a falling displacement of the upper plate and a falling position of the upper plate in the specific section; a step of obtaining whether the falling time of the upper plate is within a set range; and a step of adjusting a weight value so that the falling time of the upper plate is within the set range when the falling time of the upper plate is outside the set range.

[0029] The step of adjusting the weight value may include a step of increasing the weight value to reduce a specific speed of the upper plate in the specific section when the falling time of the upper plate is less than the lower limit of the set range.

[0030] The step of adjusting the weight value may include a step of decreasing the weight value to increase a specific speed of the upper stage in the specific section when the falling time of the upper stage exceeds the upper limit of the set range.

[0031] According to at least one of the embodiments, the weight value is adjusted or corrected based on the falling time of the upper plate during a specific section of each run for each run, and then the falling speed of the upper plate is controlled during a specific section of the next run, thereby preventing a wipe-out phenomenon of the wafer or damage to the wafer.

[0032] According to at least one of the embodiments, there is an advantage in that wafer damage can be prevented in advance, thereby reducing wafer loss.

[0033] According to at least one of the embodiments, there is an advantage in that when wafers are wiped out, production loss due to the time taken to process the wafers can be prevented.

[0034] Further scope of applicability of the embodiments will become apparent from the detailed description below. However, since various changes and modifications within the spirit and scope of the embodiments will be readily apparent to those skilled in the art, it should be understood that the detailed description and specific embodiments, such as preferred embodiments, are given by way of example only.

[0035] Fig. 1 is a front view of a wafer wrapping device according to an embodiment.

[0036] Figure 2 shows the descent speed according to multiple sections during the descent of the upper stage.

[0037] Figure 3 illustrates a case where the lower side of the upper plate is positioned at the fourth position (P4), which is the starting position of the fourth section, during the lowering of the upper plate.

[0038] Figure 4 illustrates a case where the lower side of the upper plate is positioned at the fifth position (P5), which is the end position of the fourth section, during the lowering of the upper plate.

[0039] Fig. 5 is a flowchart illustrating a control method of a wafer wrapping device according to an embodiment.

[0040] Figure 6 is a flowchart explaining S330 of Figure 5 in detail.

[0041] Figure 7 is a flowchart detailing S420 and S430 of Figure 6.

[0042] Hereinafter, embodiments disclosed in the present specification will be described in detail with reference to the attached drawings. Regardless of the drawing numbers, identical or similar components will be given the same reference numbers and redundant descriptions thereof will be omitted. The suffixes 'module' and 'part' used for components in the following description are given or used interchangeably in consideration of the ease of writing the specification, and do not have distinct meanings or roles in themselves. In addition, the attached drawings are intended to make it easier to understand the embodiments disclosed in the present specification, and the technical ideas disclosed in the present specification are not limited by the attached drawings. In addition, when an element such as a layer, region, or substrate is referred to as existing 'on' another element, this includes that it may be directly on the other element or that other intermediate elements may exist therebetween.

[0043]

[0044] In the following description, lapping and polishing may be used interchangeably.

[0045] Fig. 1 is a front view of a wafer wrapping device according to an embodiment.

[0046] Referring to FIG. 1, a wafer wrapping device (100) according to an embodiment may include a lower plate (110), an upper plate (120), a cylinder (130), a detection target (160), a plurality of position sensors (171 to 174), a displacement sensor (180), and a control unit (200).

[0047] The lower plate (110) and / or the upper plate (120) may be formed of cast iron. The lower plate (110) may be fixed. The upper plate (120) may be movable up and down.

[0048] A plurality of carriers (5) can be mounted on the lower plate (110). A plurality of wafers (10) can be mounted on the carrier (5).

[0049] A sun gear (7) may be installed in the central region of the lower platen (110), and an internal gear (6) may be installed in the peripheral region of the lower platen (110). The outer teeth of the carrier (5) are engaged with each tooth of the sun gear (7) and the internal gear (6), and the upper platen (120) and / or the lower platen (110) may rotate and the carrier (5) may rotate and revolve around the sun gear (7). Accordingly, the lower surface and / or the upper surface of the wafer (10) may be polished simultaneously.

[0050] After a plurality of wafers (10) are mounted on a plurality of carriers (5), the upper platen (120) may be lowered to engage with the lower platen (110). That is, the upper platen (120) may touch or come into proximity with the lower platen (110). The upper platen (120) engaging with the lower platen (110) or touching or coming into proximity with the lower platen (110) may be referred to as matching. After the matching between the upper platen (120) and the lower platen (110) is completed, slurry may be injected between the upper platen (120) and the lower platen (110) may be rotated, thereby lapping the lower surface and / or upper surface of the wafer (10). At this time, the upper platen (120) may be fixed or rotated. When the upper plate (120) rotates, the rotation direction of the upper plate (120) and the rotation direction of the lower plate (110) may be opposite to each other, but this is not limited thereto.

[0051] The upper plate (120) can be moved up and down. The upper plate (120) can be moved up and down by the cylinder (130) via the rod (135). The rod may be referred to as a shaft or an arm shaft. For example, when air is discharged from the cylinder (130), the rod (135) may be lowered. In this case, the upper plate (120) connected to the rod (135) may be lowered. For example, when air is injected into the cylinder (130), the rod (135) may be raised and the upper plate (120) connected to the rod (135) may be raised. By the operation of the cylinder (130), the upper plate (120) may be lowered to start the wrapping process, and may be raised after the wrapping process is completed.

[0052] The upper plate (120) may include a first upper plate and a second upper plate. The second upper plate may be connected to the first upper plate (140) via a connecting wire (150). A plurality of first pulleys (not shown) may be installed along the outer circumference of the first upper plate (140), and a plurality of second pulleys (not shown) may be installed along the outer circumference of the second upper plate (145). The first pulleys and the second pulleys may not vertically overlap. That is, the first pulleys and the second pulleys may be installed alternately. For example, the first pulley may be installed on the first upper plate (140) in a clockwise direction, and then the second pulley may be installed on the second upper plate (145). In this manner, the first and second pulleys can be installed alternately along the outer circumference of each of the first upper plate (140) and the second upper plate (145) in a clockwise direction.

[0053] The upper plate (120) may include a connecting portion (121). The connecting portion (121) may be installed on the upper side of the second upper plate (145). A rod (135) may be fixedly connected to the connecting portion (121). Accordingly, as the rod (135) moves up and down by the cylinder (130), the upper plate (120) fixed to the rod (135) may also move up and down.

[0054] Before the wrapping process, the connecting wire (150) can be adjusted so that the first upper plate (140) remains horizontal with respect to the second upper plate (145). That is, before the wrapping process, the connecting wire (150) can be adjusted and fixed so that the length of the connecting wire (150) between the first upper plate (140) and the second upper plate (145) becomes the same along the circumference of each of the first upper plate (140) and the second upper plate (145).

[0055]

[0056] Meanwhile, the detection target portion (160) can be moved up and down together with the upper plate (120). The detection target portion (160) can be moved up and down between each of the plurality of position sensors (171 to 174) and the cylinder (130). Since the detection target portion (160) is moved up and down together with the upper plate (120), the detection target portion (160) is detected, thereby detecting the position of the upper plate (120), specifically, the position of the lower side of the upper plate (120), or the matching point of the upper plate (120) and the lower plate (110), i.e., the fifth position (P5, FIG. 2) of the fourth section (T4), can be obtained. Here, the lower side of the upper plate (120) can be the lower side of the first upper plate (140).

[0057] The detection target (160) can be fixed to the upper plate (120) via the first fixing part (123) and the second fixing part (125). The first fixing part (123) can be installed on the connection part (121) and formed to be long in the horizontal direction. The second fixing part (125) can be installed on the first fixing part (123) and formed to be long in the vertical direction. In this case, the detection target (160) can be installed on the upper side of the second fixing part (125).

[0058]

[0059] Since the connecting portion (121) is included in the upper plate (120), when the upper plate (120) moves up and down, the detection target portion (160) fixed to the upper plate (120) via the first fixing portion (123) and the second fixing portion (125) can also move up and down. As will be described later, the detection target portion (160) can be detected by a plurality of position sensors (171 to 174) or a displacement sensor (180). For example, the detection target portion (160) may include a reflective member or mirror capable of reflecting light or laser, but is not limited thereto. The reflective member or mirror may be installed on the upper and side portions of the detection target portion (160).

[0060] A plurality of position sensors (171 to 174) can detect a detection target (160) that moves up and down together with the upper plate (120) to detect the lowering position of the upper plate (120), respectively. The plurality of position sensors (171 to 174) can be arranged along a vertical direction on one side of the cylinder (130). The plurality of position sensors (171 to 174) can include a first position sensor (171), a second position sensor (172), a third position sensor (173), and a fourth position sensor (174).

[0061] The first position sensor (171), the second position sensor (172), the third position sensor (173), and the fourth position sensor (174) can be arranged along the vertical direction. The first position sensor (171), the second position sensor (172), the third position sensor (173), and the fourth position sensor (174) can be positioned on the same vertical line, but are not limited thereto. The first position sensor (171), the second position sensor (172), the third position sensor (173), and the fourth position sensor (174) can be installed at different intervals along the vertical direction, but are not limited thereto.

[0062] For example, the first position sensor (171) may be installed at the highest position, and the second position sensor (172) may be installed at a position lower than the position of the first position sensor (171). The third position sensor (173) may be installed at a position lower than the position of the second position sensor (172), and the fourth position sensor (174) may be installed at a position lower than the position of the third position sensor (173).

[0063] When the upper stage (120) descends, multiple sections for different descending speed controls can be obtained using multiple position sensors (171 to 174).

[0064] As illustrated in FIG. 2, a first section (T1) can be acquired by the first position sensor (171) and the second position sensor (172). That is, when the first position (P1) is acquired by the first position sensor (171) and the second position (P2) is acquired by the second position sensor (172), the first section (T1) can be acquired using the first position (P1) and the second position (P2). For example, the detection target (160) can be lowered together with the upper plate (120). When the detection target (160) is lowered and positioned at the first position sensor (171), the position of the detection target (160) and / or the position below the upper plate (120) can be acquired as the first position (P1) by the first position sensor (171). Thereafter, when the upper plate (120) continues to descend, the detection target (160) descends past the first position sensor (171) and is located at the second position sensor (172), the position of the detection target (160) and / or the lower position of the upper plate (120) can be acquired as the second position (P2) by the second position sensor (172). Accordingly, the first section (T1) can be acquired by the first position (P1) and the second position (P2).

[0065] The second section (T2) can be acquired by the second position sensor (172) and the third position sensor (173). That is, when the second position (P2) is acquired by the second position sensor (172) and the third position (P3) is acquired by the third position sensor (173), the section between the second position (P2) and the third position (P3) can be acquired as the second section (T2). As described above, when the detection target (160) is positioned at the second position sensor (172), the second position (P2) can be acquired by the second position sensor (172). Thereafter, when the upper plate (120) continues to descend, the detection target (160) descends past the second position sensor (172) and is located at the third position sensor (173), the position of the detection target (160) and / or the lower position of the upper plate (120) can be acquired as the third position (P3) by the third position sensor (173). Accordingly, the second section (T2) can be acquired by the second position (P2) and the third position (P3).

[0066] The third section (T3) can be acquired by the third position sensor (173) and the fourth position sensor (174). That is, when the third position (P3) is acquired by the third position sensor (173) and the fourth position (P4) is acquired by the fourth position sensor (174), the section between the third position (P3) and the fourth position (P4) can be acquired as the third section (T3). As described above, when the detection target (160) is positioned at the third position sensor (173), the third position (P3) can be acquired by the third position sensor (173). Thereafter, when the upper plate (120) continues to descend, the detection target (160) descends past the third position sensor (173) and is located at the fourth position sensor (174), the position of the detection target (160) and / or the lower position of the upper plate (120) can be acquired as the fourth position (P4) by the fourth position sensor (174). Accordingly, the third section (T3) can be acquired by the third position (P3) and the fourth position (P4).

[0067] Meanwhile, as will be explained later, the fourth position (P4) and the fifth position (P5) constituting the fourth section (T4) can be acquired by the fourth position sensor (174) and the displacement sensor (180), respectively. When the upper plate (120) continues to descend and the detection target (160) is positioned at the fourth position sensor (174), tracking for the fourth section (T4) can begin. For example, when the detection target (160) is positioned at the fourth position sensor (174), the fourth position (P4), which is the starting position of the fourth section (T4), can be acquired by the fourth position sensor (174).

[0068] At the same time, the displacement of the detection target (160) can be tracked by the displacement sensor (180). The fifth position (P5), which is the end position of the fourth section (T4), can be acquired by the displacement sensor (180).

[0069] As illustrated in FIG. 2, the descending speed of the upper plate (120) can be controlled differently in each of the first section (T1), the second section (T2), the third section (T3), and the fourth section (T4). For example, the descending speed of the upper plate (120) in each of the first section (T1) and the second section (T2) can be high-speed. At this time, the descending speeds of the upper plate (120) in each of the first section (T1) and the second section (T2) can be the same or different. Therefore, the upper plate (120) is descended at a high speed during the first section (T1) and the second section (T2), thereby reducing the tact time of each run.

[0070] In the third section (T3), the descending speed of the upper plate (120) can be gradually reduced according to the descending position of the upper plate (120), that is, from the third position (P3) to the fourth position (P4). Accordingly, in the fourth section (T4), the descending speed can be rapidly reduced from high speed to low speed, thereby preventing the upper plate (120) from shaking or the wafer (10) from colliding with the upper plate (120).

[0071] In the fourth section (T4), the descending speed of the upper platen (120) may be slow. Although the drawing shows that the descending speed of the upper platen (120) in the fourth section (T4) is the same, it may also be gradually reduced. By descending the upper platen (120) at a slow speed during the fourth section (T4), a collision of the wafer (10) with the upper platen (120) can be prevented. In addition, by ensuring that the descending time of the lower platen (110) during the fourth section (T4) is within a preset range, after the lower platen (110) is matched with the upper platen (120), the lower platen (110) can be rotated at a high speed. Accordingly, a wipe-out phenomenon of the wafer (10) or damage to the wafer (10) caused by the descending time of the lower platen (110) being outside the preset range can be prevented.

[0072] Meanwhile, the specific section described in the claims below may refer to the fourth section (T4), and the first position (P1) and the second position (P2) of the specific section described in the claims below may refer to the fourth position (P4) and the fifth position (P5) of the fourth section (T4), respectively.

[0073] Each of the plurality of position sensors (171 to 174) may include a light emitting portion that emits light and a light receiving portion that receives light, but is not limited thereto.

[0074]

[0075] The displacement sensor (180) can detect a sensing target (160) that moves up and down together with the upper plate (120) to detect the downward displacement of the upper plate (120). For example, the displacement sensor (180) may include a laser-based displacement sensor (180), but is not limited thereto.

[0076] The displacement sensor (180) may be positioned higher than the uppermost position sensor (171 to 174) among the plurality of position sensors (171 to 174). The displacement sensor (180) may be installed between the cylinder (130) and the uppermost position sensor (171 to 174). The displacement sensor (180) may be installed so as to face the upper side of the detection target portion (160). Accordingly, a laser from the displacement sensor (180) is irradiated in a vertical direction, and the laser reflected by the detection target portion (160) is received by the light receiving portion of the displacement sensor (180), thereby detecting the displacement of the detection target portion (160).

[0077] The fifth position (P5, FIG. 5), which is the end position of the fourth section (T4) described above, can be determined as the point where the displacement signal detected from the displacement sensor (180) inflects. When the upper platen (120) continues to descend, the detection target portion (160) also descends, and therefore the displacement signal detected for the detection target portion (160) may vary. For example, as the detection target portion (160) descends, the displacement signal detected for the detection target portion (160) may increase. Thereafter, when the upper platen (120) continues to descend and matches the lower platen (110), the upper platen (120) may no longer descend and may stop descending. When the upper platen (120) stops descending, the detection target portion (160) also stops descending, and therefore the displacement signal detected from the displacement sensor (180) may be constantly maintained at the same value. Therefore, when the displacement signal increases and then remains constant, the inflection point where it increases and then becomes constant can be determined as the fifth position (P5), which is the end position of the fourth section (T4) described above.

[0078] Meanwhile, a plurality of position sensors (171 to 174) and a displacement sensor (180) may be fixedly connected to a support (175). The support (175) may include a first support (176) for fixing and connecting a plurality of position sensors (171 to 174) installed along a vertical direction, and a second support (177) extending from the upper side of the first support (176) toward the cylinder (130) and to which the displacement sensor (180) is fixedly connected.

[0079]

[0080] The control unit (200) can control the lowering speed of the upper plate (120) based on the lowering displacement of the upper plate (120) and the lowering position of the upper plate (120). As described above, the lowering position of the detection target part (160) can be detected by a plurality of displacement sensors (180), and the lowering displacement of the detection target part (160) can be detected by the displacement sensors (180). In other words, the lowering position of the upper plate (120) can be detected by a plurality of displacement sensors (180), and the lowering displacement of the upper plate (120) can be detected by the displacement sensors (180).

[0081] The control unit (200) can control the lowering speed of the upper plate (120) differently for each of a plurality of sections obtained according to the lowering of the upper plate (120), as illustrated in FIG. 2. The plurality of sections can be obtained using a plurality of position sensors (171 to 174) and a displacement sensor (180). For example, the first section (T1) can be a section between a first position (P1) and a second position (P2) obtained by each of the first position sensor (171) and the second position sensor (172). For example, the second section (T2) can be a section between a second position (P2) and a third position (P3) obtained by each of the second position sensor (172) and the third position sensor (173). For example, the third section (T3) may be a section between the third position (P3) and the fourth position (P4) acquired by the third position sensor (173) and the fourth position sensor (174), respectively.

[0082] For example, the fourth section (T4) may be a section between the fourth position (P4) and the fifth position (P5) acquired by the fourth position sensor (174) and the displacement sensor (180), respectively. In particular, the fifth position (P5) may be determined as a point at which a displacement signal detected from the displacement sensor (180) inflects.

[0083] The control unit (200) can precisely control the lowering speed of the upper plate (120) in the fourth section (T4). The control unit (200) can prevent the wipe-out phenomenon of the wafer (10) or damage to the wafer (10) by controlling the lowering time of the upper plate (120) in the fourth section (T4) to be within the range set by the recipe.

[0084] Specifically, the control unit (200) obtains the falling time of the upper plate (120) based on the falling displacement of the upper plate (120) and the falling position of the upper plate (120) in the fourth section (T4), obtains whether the falling time of the upper plate (120) is within a range set in the recipe, and if the falling time of the upper plate (120) is outside the set range, adjusts or corrects the weight value so that the falling time of the upper plate (120) is included within the set range.

[0085] For example, the fourth position (P4) of the fourth section (T4) can be acquired by the fourth position sensor (174) (Fig. 3), and the fifth position (P5) of the fourth section (T4) can be acquired by the displacement sensor (180) (Fig. 4).

[0086] As illustrated in FIG. 3, when the detection target (160) is lowered together with the upper plate (120), and the detection target (160) is positioned at the fourth position sensor (174), the position of the detection target (160) and / or the position of the lower side of the upper plate (120) can be acquired as the fourth position (P4) by the fourth position sensor (174). When the detection target (160) is positioned at the fourth position sensor (174), the displacement sensor (180) may be operated so that the laser may be irradiated in a vertical direction, but this is not limited thereto.

[0087] The sensing target (160) may descend together with the upper plate (120), and the sensing target (160) may descend toward the lower plate (110) past the fourth position sensor (174). As the sensing target (160) descends, the displacement signal detected by the displacement sensor (180) may change. For example, the displacement signal may increase as the sensing target (160) descends, but this is not limited thereto. If the upper plate (120) touches the lower plate (110), the upper plate (120) may no longer descend. In this case, the displacement signal detected by the displacement sensor (180) may be maintained at the same value. Therefore, the point at which the displacement signal inflects, that is, the inflection point where it increases and then becomes constant, may be determined as the fifth position (P5) of the fourth section (T4).

[0088] Meanwhile, if the falling time of the upper plate (120) is less than the lower limit of the above-described range, the control unit (200) may increase the weight value to reduce the falling speed of the upper plate (120) in the fourth section (T4). In addition, if the falling time of the upper plate (120) exceeds the upper limit of the above-described range, the control unit (200) may decrease the weight value to increase the falling speed of the upper plate (120) in the fourth section (T4).

[0089]

[0090] Fig. 5 is a flowchart illustrating a control method of a wafer wrapping device according to an embodiment.

[0091] Referring to FIGS. 1 and 5, when a run is first started, the upper plate (120) can be lowered. That is, the load (135) is lowered by the air discharged from the cylinder (130), and the upper plate (120) connected to the load (135) can be lowered.

[0092] When the upper plate (120) is lowered, the detection target (160) attached to the upper plate (120) may also be lowered. At this time, the detection target (160) may be lowered between the cylinder (130) and a plurality of position sensors (171 to 174) arranged in a vertical direction.

[0093] A plurality of position sensors (171 to 174) can each detect a detection target (160) descending together with the upper plate (120) (S310). The detection target (160) can descend vertically along the side of the cylinder (130).

[0094] Each of the plurality of position sensors (171 to 174) may include a light emitting portion and a light receiving portion. Light may be irradiated from each of the light emitting portions of the plurality of position sensors (171 to 174) toward the side of the cylinder (130). The amount of light or light intensity received by each of the light receiving portions of the plurality of position sensors (171 to 174) may vary depending on whether or not the detection target portion (160) is located at each of the plurality of position sensors (171 to 174).

[0095] In this way, based on the amount of light or light intensity received, the position of the detection target (160) or the section between the previous position and the current position of the adjacent detection target (160) can be acquired. When the position of the detection target (160) is acquired, the position of the lower side of the upper plate (120) to which the detection target (160) is attached can also be acquired. In addition, when the section of the detection target (160) is acquired, the section between the previous position and the current position of the lower side of the upper plate (120) to which the detection target (160) is attached can be acquired.

[0096] Meanwhile, when the upper plate (120) is lowered, the detection target (160) attached to the upper plate (120) can be lowered vertically along the side of the cylinder (130). As such, each time the vertically lowered detection target (160) passes each of the plurality of position sensors (171 to 174) arranged along the vertical direction, a plurality of positions (P1 to P5) can be acquired, as illustrated in FIG. 2.

[0097] For example, when a run is started, the upper plate (120) is lowered and matched with the lower plate (110), and then the lower plate (110) and / or the upper plate (120) are rotated at high speed, so that a plurality of wafers (10) can be polished on the lower plate (110).

[0098] The multiple positions (P1 to P5) shown in Fig. 2 can be obtained in the process of matching the upper plate (120) with the lower plate (110) from the start of the run.

[0099] First, when the detection target (160) is lowered together with the upper plate (120) by the start of the run, and the detection target (160) passes the first position sensor (171), the detection target (160) can be detected by the first position sensor (171). Based on the detection result by the control unit (200), that is, the amount of light or light intensity of light reflected by the detection target (160), the first position (P1) can be detected.

[0100] When the detection target (160) passes the second position sensor (172) via the first position sensor (171), the detection target (160) can be detected by the second position sensor (172). The second position (P2) can be detected by the control unit (200) based on the detection result, that is, the amount of light or the intensity of light reflected by the detection target (160). The first section (T1) can be obtained by the first position (P1) and the second position (P2). When the first position (P1) is detected, the control unit (200) can drive the cylinder (130) so that the upper plate (120) descends at a descending speed set in the recipe, for example, the first descending speed. The upper plate (120) can descend at the first descending speed until the second position (P2) is detected. The first descending speed can be high speed.

[0101] Thereafter, when the detection target portion (160) passes the third position sensor (173) via the second position sensor (172), the detection target portion (160) can be detected by the third position sensor (173). The third position (P3) can be acquired based on the detection result, that is, the amount of light or the intensity of light reflected by the detection target portion (160), by the control unit (200). The second section (T2) can be acquired by the second position (P2) and the third position (P3). When the second position (P2) is detected, the control unit (200) can drive the cylinder (130) so that the upper plate (120) descends at a descending speed set in the recipe, for example, the second descending speed. The upper plate (120) can descend at the second descending speed until the third position (P3) is detected. The second descending speed can be high speed. The second descent speed may be the same as the first descent speed, but is not limited thereto.

[0102]

[0103] Thereafter, when the detection target (160) passes the fourth position sensor (174) via the third position sensor (173), the detection target (160) can be detected by the fourth position sensor (174). The fourth position (P4) can be acquired based on the detection result, that is, the amount of light or the intensity of light reflected by the detection target (160), by the control unit (200). The third section (T3) can be acquired by the third position (P3) and the fourth position (P4). When the third position (P3) is detected, the control unit (200) can drive the cylinder (130) so that the upper plate (120) descends at a descending speed set in the recipe, for example, the third descending speed. The upper plate (120) can be descended at the third descending speed until the fourth position (P4) is detected. The third descent speed can be gradually reduced to the fourth position (P4).

[0104] For example, the first position (P1) to the fourth position (P4) may be the positions of the first position sensor (171) to the fourth position sensor (174) through which the detection target (160) passes, respectively. For example, the first position (P1) to the fourth position (P4) may be the positions on the lower side of the upper plate (120) when the detection target (160) is positioned at the first position sensor (171) to the fourth position sensor (174), respectively.

[0105] Meanwhile, when the fourth position (P4) is detected, the displacement sensor (180) can detect the detection target part (160) descending together with the upper plate (120) (S320). That is, when the fourth position (P4) is detected, the control unit (200) can drive the displacement sensor (180) to irradiate the laser toward the detection target part (160). When the detection target part (160) descends past the fourth position (P4), the control unit (200) can detect the downward displacement of the detection target part (160), i.e., the displacement signal, using the fourth displacement sensor (180).

[0106] As the detection target (160) descends, the displacement signal detected from the detection target (160) may change. For example, as the detection target (160) descends, the displacement signal may increase.

[0107] Meanwhile, the upper plate (120) may descend and touch the lower plate (110). In other words, the upper plate (120) may be matched with the lower plate (110). In this case, the sensing target (160) attached to the upper plate (120) may no longer descend and may stop descending. After the upper plate (120) is matched with the lower plate (110), the displacement signal for the sensing target (160) may be maintained at a constant value.

[0108] Accordingly, the control unit (200) can track the change in the displacement signal for the detection target unit (160) and determine the point where the displacement signal changes as the fifth position (P5). The fifth position (P5) may be the position where the lower side of the upper plate (120) touches the upper side of the lower plate (110).

[0109] The fourth section (T4) can be obtained by the fourth position (P4) and the fifth position (P5).

[0110] The specific section described in the claims below may refer to the fourth section (T4), and the first position (P1) and the second position (P2) of the specific section described in the claims below may refer to the fourth position (P4) and the fifth position (P5) of the fourth section (T4), respectively.

[0111] The control unit (200) can prevent the wipe-out phenomenon of the wafer (10) or damage to the wafer (10) by controlling the lowering speed of the lower plate (110) in the fourth section (T4), i.e., the fourth lowering speed.

[0112] The control unit (200) can control the lowering speed of the upper plate (120) based on the lowering displacement of the upper plate (120) and the lowering position of the upper plate (120) (S330).

[0113] As described above, the fourth position (P4) can be detected using the fourth position sensor (174), and the fifth position (P5) can be detected using the displacement sensor (180). The section between the fourth position (P4) and the fifth position (P5) can be determined as the fourth section (T4).

[0114] As illustrated in FIG. 6, the control unit (200) can obtain the lowering time of the upper plate (120) based on the lowering displacement of the upper plate (120) and the lowering position of the upper plate (120) in a specific section, i.e., the fourth section (T4) (S410). That is, the control unit (200) can obtain the time taken for the lower side of the upper plate (120) to lower from the fourth position (P4) to the fifth position (P5) in the fourth section (T4).

[0115] The control unit (200) can obtain whether the descent time of the upper plate (120) is within the range set in the recipe (S420).

[0116] If the descent time of the upper plate (120) is outside the range set in the recipe, the control unit (200) may adjust the weight value to control the descent speed of the upper plate (120) in the next run (S430). The adjusted weight value may be stored in memory or updated in the recipe.

[0117] When the run is completed, the upper plate (120) can be returned to its original position. That is, the load (135) can be raised by the air injected into the cylinder (130), and the upper plate (120) attached to the load (135) can be raised. In other words, by the operation of the cylinder (130), the upper plate (120) can be lowered to start the wrapping process, and after the wrapping process is completed, the upper plate (120) can be raised, thereby completing one run.

[0118] Meanwhile, when the next run is operated (S440), the control unit (200) can control the lowering speed of the upper platen (120) so that the adjusted weight value is included within the range set in the recipe during the fourth section (T4) of the next run (S450). Here, the adjusted weight value may be the weight value adjusted in the previous run, but is not limited thereto. Since the lowering speed of the upper platen (120) is controlled so that the lowering speed of the upper platen (120) is included within the range set in the recipe, after the upper platen (120) is matched to the lower platen (110), the lower platen (110) and / or the upper platen (120) are rotated at high speed, thereby preventing the wipe-out phenomenon of the wafer (10) or damage to the wafer (10).

[0119] Meanwhile, in S420, if the lowering time of the upper plate (120) is within the range set in the recipe, it may mean that the upper plate (120) matches the lower plate (110). In this case, the control unit (200) may perform a polishing process on a plurality of wafers (10) on the lower plate (110) by rotating the lower plate (110) and / or the upper plate (120) at high speed.

[0120] Referring to Fig. 7, the adjustment of the weight value is described in detail.

[0121] As illustrated in FIG. 7, if the falling time of the upper plate (120) is outside the range set in the recipe, the control unit (200) can determine whether the falling time of the upper plate (120) is less than the lower limit of the range set in the recipe (S510). For example, if the range set in the recipe is 28 to 32 seconds, the control unit (200) can determine whether the falling time of the upper plate (120) is less than 28 seconds.

[0122] If the falling time of the upper plate (120) is less than the lower limit of the range set in the recipe, the control unit (200) may increase the weight value (S520). The weight value may be increased to a preset value. The weight value may be increased in proportion to how much the falling time of the upper plate (120) deviates from the lower limit of the range set in the recipe. For example, if the falling time of the upper plate (120) is 27 seconds, the weight value may be +1. For example, if the falling time of the upper plate (120) is 26 seconds, the weight value may be +2.

[0123] Due to the increased weight value in this way, the descent speed of the upper plate (120) during the fourth section (T4) of the next run is slowed down, so that the descent time of the upper plate (120) can be included within the range set in the recipe.

[0124] If the falling time of the upper plate (120) is outside the range set in the recipe, the control unit (200) can determine whether the falling time of the upper plate (120) exceeds the upper limit of the range set in the recipe (S530). For example, if the range set in the recipe is 28 to 32 seconds, the control unit (200) can determine whether the falling time of the upper plate (120) exceeds 32 seconds.

[0125] If the falling time of the upper plate (120) exceeds the upper limit of the range set in the recipe, the control unit (200) may decrease the weight value (S540). The weight value may be decreased to a preset value. The weight value may be decreased in proportion to how much the falling time of the upper plate (120) deviates from the upper limit of the range set in the recipe. For example, if the falling time of the upper plate (120) is 33 seconds, the weight value may be -1. For example, if the falling time of the upper plate (120) is 34 seconds, the weight value may be -2.

[0126] Due to the reduced weight value in this way, the descent speed of the upper plate (120) during the fourth section (T4) of the next run is accelerated, so that the descent time of the upper plate (120) can be included within the range set in the recipe.

[0127] According to an embodiment, for each run, a weight value is adjusted based on the falling time of the upper plate (120) during the fourth section (T4) of each run, so that the falling speed of the upper plate (120) is controlled during the fourth section (T4) of the next run, thereby preventing a wipe-out phenomenon of the wafer (10) or damage to the wafer (10).

[0128]

[0129] The above detailed description should not be construed as limiting in any respect and should be considered illustrative only. The scope of the embodiments should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalency range of the embodiments are intended to be included within the scope of the embodiments.

Claims

1. Lower body; An upper plate arranged on the lower plate and interlocked with the lower plate to wrap the wafer; A cylinder that moves the upper plate up and down through the load; The detection target descending together with the above-mentioned upper stage; A plurality of position sensors that detect a detection target that descends together with the upper plate to detect the descending position of the upper plate; A displacement sensor that detects a detection target that descends together with the upper plate to detect the downward displacement of the upper plate; and A control unit that controls the lowering speed of the upper plate based on the lowering displacement of the upper plate and the lowering position of the upper plate; Wafer wrapping device.

2. In paragraph 1, The descending speed of the above-mentioned upper plate includes a specific speed of the above-mentioned upper plate in a specific section, The above specific section is a section between a first position where the lower side of the upper plate is located when the detection target is located at the lowest position sensor among the plurality of position sensors and a second position where the lower side of the upper plate is located when the upper plate touches the lower plate. Wafer wrapping device.

3. In paragraph 2, The above control unit, The point at which the displacement signal detected from the displacement sensor is inflected is determined as the second position. Wafer wrapping device.

4. In paragraph 2, The above control unit, In the above specific section, the descending time of the upper plate is obtained based on the descending displacement of the upper plate and the descending position of the upper plate, Obtain whether the descent time of the above-mentioned upper limit is within the set range, If the falling time of the above-mentioned upper stage is outside the set range, the weight value is adjusted so that the falling time of the above-mentioned upper stage is within the set range. Wafer wrapping device.

5. In paragraph 4, The above control unit, If the falling time of the above-mentioned upper stage is less than the lower limit of the above-mentioned set range, the weight value is increased to reduce the specific speed of the above-mentioned upper stage in the specific section. Wafer wrapping device.

6. In paragraph 5, The above control unit, If the falling time of the above-mentioned upper limit exceeds the upper limit of the above-mentioned set range, the weight value is reduced to increase the specific speed of the above-mentioned upper limit in the specific section. Wafer wrapping device.

7. In paragraph 1, The above plurality of position sensors are installed along the vertical direction on one side of the cylinder, Wafer wrapping device.

8. In paragraph 7, The displacement sensor is positioned higher than the uppermost position sensor among the plurality of position sensors and is installed between the cylinder and the uppermost position sensor. Wafer wrapping device.

9. In paragraph 8, A wafer wrapping device comprising a support member to which the plurality of position sensors and the displacement sensor are fixedly connected.

10. In paragraph 9, The above support part, A first support member for fixing and connecting a plurality of position sensors installed along the vertical direction; and A second support portion extending from the upper side of the first support portion toward the cylinder, to which the displacement sensor is fixedly connected; Wafer wrapping device.

11. In paragraph 8, The above detection target portion moves up and down between each of the plurality of position sensors and the cylinder. Wafer wrapping device.

12. A method for controlling a wafer wrapping device including a lower platen, an upper platen positioned on the lower platen and interlocked with the lower platen to wrap a wafer, and a cylinder for moving the upper platen up and down through a load, A step of detecting a detection target part descending together with the upper plate to detect a descending position of the upper plate by the plurality of position sensors; A step of detecting a detection target part that descends together with the upper plate to detect a downward displacement of the upper plate by the displacement sensor; and A step of controlling the lowering speed of the upper plate based on the lowering displacement of the upper plate and the lowering position of the upper plate; including; A method for controlling a wafer wrapping device.

13. In paragraph 12, The descending speed of the above-mentioned upper plate includes a specific speed of the above-mentioned upper plate in a specific section, The above specific section is a section between a first position where the lower side of the upper plate is located when the detection target is located at the lowest position sensor among the plurality of position sensors and a second position where the lower side of the upper plate is located when the upper plate touches the lower plate. A method for controlling a wafer wrapping device.

14. In paragraph 13, A step of determining a point at which a displacement signal detected from the displacement sensor is inflected as the second position; A method for controlling a wafer wrapping device.

15. In paragraph 13, A step of obtaining the descending time of the upper plate based on the descending displacement of the upper plate and the descending position of the upper plate in the above specific section; A step of obtaining whether the descending time of the above-mentioned upper limit is within a set range; and Including a step of adjusting a weight value so that the falling time of the upper stage falls within the set range when the falling time of the upper stage falls outside the set range; A method for controlling a wafer wrapping device.

16. In paragraph 15, The step of adjusting the above weight value is: A step of increasing the weight value to reduce a specific speed of the upper stage in the specific section when the falling time of the upper stage is less than the lower limit of the set range; A method for controlling a wafer wrapping device.

17. In paragraph 16, The step of adjusting the above weight value is: A step of reducing the weight value to increase a specific speed of the upper stage in the specific section when the falling time of the upper stage exceeds the upper limit of the set range; A method for controlling a wafer wrapping device.

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