In-situ detection device and in-situ detection method for edge-cut wafer

Abstract

The present invention discloses an in-situ detection device and an in-situ detection method for edge-cut wafers, which comprise: an inclined hole, which is arranged at the top of a bracket; a medium source, which is connected to the inclined hole through a pipeline; a pressure sensor, which is arranged in the pipeline between the inclined hole and the medium source to detect the pressure of the pipeline; a control unit, which is connected to the pressure sensor to determine whether the wafer is in place according to the pressure of the pipeline; wherein the top of the bracket is also provided with a groove overlapping with the inclined hole, a pad is installed inside the groove, and the pad partially blocks the inclined hole to form a detection hole; if the wafer on the bracket is in place, the wafer partially or completely blocks the detection hole to cause a pressure change in the pipeline.

Description

Technical Field

[0001] The present invention belongs to the field of semiconductor technology, and in particular, relates to an in-situ detection device and an in-situ detection method for edge-cut wafers. Background Art

[0002] In the semiconductor field, the edge of the wafer needs to be trimmed so that a thinned annular area appears on the edge of the wafer to meet the requirements of wafer manufacturing.

[0003] During the chemical mechanical polishing process, the in-situ detection of edge-cut wafers is prone to misjudgment, affecting the normal interaction of the wafer in the wafer exchange device (load cup). Specifically:

[0004] (1) Due to the requirements of the wafer device area, the area that the wafer can contact is limited to within 2.5 mm of the edge; the 2.5 mm edge area is not only used for wafer support, but also for in-situ detection of the wafer, and the space used is limited;

[0005] (2) In order to prevent the device area from being polluted by light, optical sensors cannot be used for detection;

[0006] (3) Conventional water pressure detection relies on the edge of the wafer covering the water outlet, and determines whether the wafer is in place by the pressure difference between the presence and absence of the wafer. However, for edge-cut wafers, it is difficult for the wafer to completely or mostly cover the water outlet, resulting in a smaller pressure difference when there is a wafer or not, which can easily cause false alarms and affect the normal interaction of the wafers;

[0007] (4) Since there are many specifications for wafer edge cutting dimensions (trimming dimensions), replacing the entire mechanical components to match wafers of different specifications has the disadvantages of low switching efficiency and high overall cost. Summary of the invention

[0008] The present invention aims to solve one of the technical problems existing in the prior art to at least some extent.

[0009] To this end, the present invention provides an in-situ detection device for edge-cut wafers, which comprises:

[0010] An oblique hole is provided on the top of the bracket;

[0011] A medium source, which is connected to the inclined hole through a pipeline;

[0012] A pressure sensor is arranged on the pipeline between the inclined hole and the medium source to detect the pressure of the pipeline;

[0013] A control unit connected to the pressure sensor to determine whether the wafer is in place according to the pressure of the pipeline;

[0014] Among them, the top of the bracket is also configured with a groove overlapping with the inclined hole, and a pad is installed inside the groove, and the pad partially blocks the inclined hole to form a detection hole; if the wafer on the bracket is in place, the wafer partially or completely blocks the detection hole to cause a pressure change in the pipeline.

[0015] As a preferred embodiment, the groove is located outside the inclined hole, and the pad partially blocks the outer side of the inclined hole.

[0016] As a preferred embodiment, the pad is provided with an auxiliary hole, and the auxiliary hole is arranged to match the position of the inclined hole.

[0017] As a preferred embodiment, the auxiliary hole is a circular hole, which is arranged through the thickness direction of the pad and is located in the middle of the pad.

[0018] As a preferred embodiment, the auxiliary hole is a waist-shaped hole or an elliptical hole, the pad is installed in the groove, and the short side of the auxiliary hole is oriented toward the center of the bracket.

[0019] As a preferred embodiment, the auxiliary hole is an arc-shaped hole opened on one side, and is located at the edge of the pad.

[0020] As a preferred embodiment, the material of the backing plate is the same as that of the top of the bracket, and the backing plate is made of wear-resistant plastic.

[0021] As a preferred embodiment, the bracket is a disc-shaped structure, with multiple detection groups evenly distributed on the top, each detection group is configured with at least one detection hole; the detection holes configured in each detection group have different shapes and / or opening sizes.

[0022] Meanwhile, the present invention also discloses a wafer exchange device, which comprises the above-mentioned in-situ detection device.

[0023] In addition, the present invention also provides a wafer in-situ detection method, which uses the above-mentioned in-situ detection device and includes:

[0024] S1, transporting the medium source to the detection hole through the pipeline and the inclined hole;

[0025] S2, when there is no wafer on the top of the bracket, read the pressure value P0 of the pressure sensor;

[0026] S3, when there is a wafer on the top of the bracket and the wafer completely blocks the detection hole, read the pressure value P1 of the pressure sensor;

[0027] S4, when the pressure P read by the pressure sensor corresponding to any detection group is greater than Pm, the wafer on the top of the bracket is in place, wherein P0<Pm<P1.

[0028] The beneficial effects of the present invention include: a detachable pad is provided on the bracket, which effectively controls the size, shape and position of the detection hole, enhances the applicability to edge-cut wafers, reduces the probability of false alarms in in-situ detection, and ensures the smoothness of wafer interaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The advantages of the present invention will become clearer and easier to understand through the detailed description made in conjunction with the following drawings, which are only schematic and do not limit the scope of protection of the present invention, wherein:

[0030] Figure 1 It is a partial cross-sectional view of a wafer in-situ detection device in the prior art;

[0031] Figure 2 yes Figure 1 A partial enlarged view of the middle A;

[0032] Figure 3 is a partial top view of a bracket 10' in the prior art;

[0033] Figure 4 is a schematic diagram of an in-situ detection device for edge-cut wafers according to the present invention;

[0034] Figure 5 is a partial cross-sectional view of the bracket 10 of the present invention;

[0035] Figure 6 yes Figure 5 A partial enlarged view of the dotted box in the middle;

[0036] Figure 7 is a schematic structural diagram of the groove 12 of the present invention;

[0037] Figure 8 is a schematic structural diagram of the pad 13 of the present invention;

[0038] Fig. 9 is a schematic diagram of a detection hole formed on the bracket 10 of the present invention;

[0039] Fig.10 It is a gas path diagram corresponding to the detection hole of the present invention;

[0040] Fig.11 is a schematic diagram of another embodiment of the detection hole of the present invention;

[0041] Fig.12 is a schematic diagram of a detection group configured on the bracket 10 of the present invention;

[0042] Fig.13 It is a flow chart of a wafer in-situ detection method described in the present invention. DETAILED DESCRIPTION

[0043] The technical scheme of the present invention is described in detail below in conjunction with specific embodiments and their accompanying drawings. The embodiments recorded herein are specific embodiments of the present invention, which are used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary and should not be construed as limitations on the embodiments of the present invention and the scope of protection of the present invention. In addition to the embodiments recorded herein, those skilled in the art can also adopt other obvious technical solutions based on the contents disclosed in the claims of this application and its specification, including technical solutions that adopt any obvious replacements and modifications to the embodiments recorded herein.

[0044] The drawings of this specification are schematic diagrams, which assist in explaining the concept of the present invention and schematically show the shapes of various parts and their mutual relationships. It should be understood that in order to clearly show the structures of various components of the embodiments of the present invention, the drawings are not drawn according to the same scale, and the same reference numerals are used to represent the same parts in the drawings.

[0045] In the present invention, "Chemical Mechanical Polishing (CMP)" is also called "Chemical Mechanical Planarization (CMP)", and the wafer (Wafer, W) is also called substrate (Substrate), and their meanings and actual functions are equivalent.

[0046] Figure 1 It is a partial cross-sectional view of a wafer in-situ detection device in the prior art. To ensure the machinability of the detection hole, an inclined through hole 11 ′ is provided at the edge of the bracket 10 ′. Figure 2 yes Figure 1 In the partial enlarged view of A in the middle, for edge-cut wafers, the edge of the wafer may only cover part of the through hole 11', so that the pressure change of the pipeline connected to the through hole 11' is small. That is, whether the wafer is in place or not, the pressure in the pipeline does not change much, which can easily lead to misjudgment, resulting in wafer interaction failure and affecting the normal turnover of the wafer.

[0047] In addition, the cross-sectional shape of the through hole 11' on the top surface of the bracket 10' is an ellipse. Figure 3 As shown, the major axis of the elliptical hole is opposite to the center of the bracket 10'. If the wafer W is offset from the center of the bracket 10', the wafer will only cover a portion of the through hole 11', causing a false alarm of the wafer in-situ detection.

[0048] In order to solve the above technical problems, the present invention provides an in-situ detection device for edge-cut wafers, and its structural schematic diagram is as follows: Figure 4The position detection device is arranged around the bracket 10, which is a disc-shaped component and is concentrically arranged in the cup body 50. By controlling the vertical movement of the bracket 10 and the cup body 50, the interactive transmission of the wafers is realized.

[0049] Furthermore, the in-situ detection device includes a medium source 20, a pressure sensor 30 and a control unit 40; an inclined hole 11 is provided at the top of the bracket 10, and the inclined hole 11 is connected to the medium source 20 through a pipeline; the pressure sensor 30 is provided on the pipeline between the inclined hole 11 and the medium source 20 to detect the pressure change of the pipeline; the control unit 40 is connected to the pressure sensor 30 to determine whether the wafer is in place according to the pressure change of the pipeline.

[0050] The top of the bracket 10 is also provided with a Figure 6 The groove 12 is shown, and a pad 13 is installed inside the groove 12. The pad 13 partially blocks the inclined hole 11 to form a detection hole. If the wafer on the bracket 10 is in place, the wafer partially or completely blocks the detection hole to cause a pressure change in the pipeline.

[0051] Specifically, if there is no wafer on the top surface of the bracket 10, the pressure of the pipeline obtained by the pressure sensor 30 is P0; if a wafer is placed on the top surface of the bracket 10, the edge of the wafer blocks the detection hole, and the pressure in the pipeline increases, and the control unit 40 determines whether the wafer is in place based on the increase in pressure.

[0052] Figure 5 is a partial cross-sectional view of the bracket 10 in the present invention, Figure 6 yes Figure 5 The pad 13 partially blocks the inclined hole 11 to form a smaller detection hole, so that the edge-cut wafer has a higher probability of blocking the detection hole, avoiding the existing technology in which the through hole 11' is partially blocked, resulting in little change in pipeline pressure and inability to accurately determine the wafer is in place.

[0053] As an embodiment of the present invention, the groove 12 is located outside the inclined hole 11. Figure 6 As shown, the pad 13 partially blocks the outer side of the inclined hole 11. Since the edge-cut wafer forms a thinned annular area at the outer edge, it is necessary to set the area of ​​the wafer edge with normal thickness as the detection area to ensure the accuracy of the detection.

[0054] In order to improve the accuracy of fixing the backing plate 13, a positioning pin 13b is disposed at the bottom of the backing plate 13. Figure 8 Correspondingly, the bottom surface of the groove 12 is matched with a pin hole 12a, as shown in FIG. Figure 7 The number of the pin holes 12a is a pair, which assists the positioning of the backing plate 13 and ensures quick and accurate installation.

[0055] Fig. 9 It is a top view of the pad 13 installed in the groove 12. Since the pad 13 blocks most of the cross-sectional hole corresponding to the inclined hole 11, the detection hole formed is a long hole. The short axis direction of the long hole points to the center of the bracket 10. Therefore, even if the detection area of ​​the wafer is small, the detection hole can be completely covered, effectively improving the accuracy of wafer in-situ detection.

[0056] Fig. 9 In the embodiment shown, the number of detection holes formed on the bracket 10 is 3. The detection holes 14 are individually configured with corresponding pressure sensors 30, such as Fig.10 The medium source 20 provides a medium with a certain pressure, and the medium can be water, gas or a gas-liquid mixture and is transported through a pipeline; a flow regulator 21, a one-way valve 22 and a pressure reducing valve 23 are also arranged on the pipeline. The flow regulator 21 can stabilize the medium flow in the pipeline, so that the pressure of the detection hole is stable; the one-way valve 22 can prevent the medium from flowing back, and the pressure reducing valve 23 can adjust the pressure in the pipeline, which is suitable for different detection conditions.

[0057] As an embodiment of the present invention, the pad 13 is provided with an auxiliary hole 13 a , and the auxiliary hole 13 a is arranged to match the position of the inclined hole 11 to form a detection hole. Figure 8 In the embodiment shown, the auxiliary hole 13a is a blind hole arranged downward along the top surface of the pad 13, and is located at the edge of the pad 13. It is understandable that the auxiliary hole 13a can also be an arc-shaped hole opened on one side and arranged through the thickness of the pad 13, such as Fig.11 As shown, the auxiliary hole 13a is arranged opposite to the inclined hole 11 to form a detection hole.

[0058] It is understandable that the auxiliary hole 13a may also be a circular hole, which is arranged through the thickness direction of the pad 13 and located in the middle of the pad 13. When using this auxiliary hole 13a, the groove 12 provided on the bracket 10 needs to completely cover the cross-sectional opening of the inclined hole 11.

[0059] As an embodiment of the present invention, the auxiliary hole 13a is a waist-shaped hole or an elliptical hole, and the pad 13 is installed in the groove 12. The short side direction of the auxiliary hole 13a faces the center of the bracket 10, so that the detection area of ​​the wafer covers the detection hole formed by the auxiliary hole 13a and the inclined hole 11. Specifically, when there is no wafer on the bracket 10, the detection hole on the bracket 10 is open, and the pipeline pressure obtained by the pressure sensor 30 is low; when there is a wafer on the bracket 10, the detection hole on the bracket 10 is covered, and the pipeline pressure obtained by the pressure sensor 30 is higher than when there is no wafer. By setting a certain pressure threshold, a pressure less than the threshold indicates that there is no wafer, and a pressure greater than the threshold indicates that there is a wafer, thereby improving the accuracy of wafer in-situ detection.

[0060] In order to reduce the interference of the pad 13 on the interaction of the wafer, the pad 13 is made of the same material as the top of the bracket 10. Specifically, the pad 13 can be made of wear-resistant plastic, such as polyphenylene sulfide (Polyphenylene sulfide), polyetheretherketone (PEEK), etc. When the bracket 10 is processed and manufactured, the pad 13 needs to be pre-installed in the groove 12, and then the top surface of the bracket 10 is processed as a whole to ensure the flatness of the top surface and realize accurate wafer in-situ detection.

[0061] In the present invention, the shape, size and position of the detection hole can be controlled by adjusting the opening size of the auxiliary hole 13a of the pad 13, which can be used for in-situ detection of wafers of different specifications, eliminating the step of switching the in-situ detection device for edge-cut wafers of different specifications, and effectively expanding the scope of application of the in-situ detection device.

[0062] In order to improve the accuracy of the in-situ detection, a plurality of detection groups may be evenly distributed on the top of the bracket 10, such as a first detection group 10A, a second detection group 10B and a third detection group 10C. Fig.12 Each detection group is configured with at least one detection hole, and the detection holes configured in each detection group have different shapes and / or opening sizes, so as to improve the applicability of the in-situ detection device.

[0063] The diameter of the detection hole formed on the bracket 10 should not be too small, as it is not conducive to processing and manufacturing. Preferably, the diameter of the detection hole formed on the bracket 10 is 0.6 mm-1 mm.

[0064] At the same time, the present invention also discloses a wafer exchange device (load cup), such as Figure 4 As shown, it includes the above-mentioned in-situ detection device, and the bracket 10 is concentrically arranged in the cup body 50 to realize the interaction of the wafer between the polishing head and the wafer exchange device, or the interaction of the wafer between the robot and the wafer exchange device.

[0065] In addition, the present invention also discloses a wafer in-situ detection method, which uses the above-mentioned in-situ detection device, and its flow chart is as follows: Fig.13 As shown, the following steps are included:

[0066] S1, transporting the medium source 20 to the detection hole through the pipeline and the inclined hole 11;

[0067] Specifically, the bracket 10 is provided with a groove 12, inside of which a pad 13 is installed. The pad 13 is provided with an auxiliary hole 13a opposite to the inclined hole 11 or has no auxiliary hole 13a. The pad 13 cooperates with the inclined hole 11 to form a detection hole for in-situ detection.

[0068] S2, when there is no wafer on the top of the bracket 10, read the pressure value P0 of the pressure sensor 30;

[0069] That is, when there is no wafer on the bracket 10 , the detection hole is completely open, and at this time, the pressure value P0 in the pipeline is measured by the pressure sensor 30 .

[0070] S3, when there is a wafer on the top of the bracket 10 and the wafer completely blocks the detection hole, the pressure value of the pressure sensor 30 is read as P1;

[0071] That is, the wafer on the bracket 10 completely blocks or covers the detection hole, and the pressure on the pipeline will increase significantly. At this time, the pressure value P1 on the pipeline is obtained through the pressure sensor.

[0072] S4, when the pressure P read by the pressure sensor 30 corresponding to any detection group is greater than Pm, the wafer on the top of the bracket 10 is in place, wherein P0<Pm<P1.

[0073] Specifically, Pm is a threshold value, which can take any value between P0 and P1. In order to adjust the sensitivity of the in-situ detection, the threshold values ​​Pm set for the detection holes in the same detection group can be different.

[0074] Since the pad 13 is provided on the bracket 10, the size, shape and position of the detection hole are effectively controlled, the applicability to edge-cut wafers is enhanced, the probability of false alarms in situ detection is reduced, and the smoothness of wafer interaction is ensured.

[0075] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0076] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. An in-situ detection device for edge-cut wafers, comprising: an oblique hole provided on the top of the bracket; a medium source, which is connected to the inclined hole through a pipeline; A pressure sensor is provided on the pipeline between the inclined hole and the medium source to detect the pressure of the pipeline; a control unit connected to the pressure sensor to determine whether the wafer is in place based on the pressure of the pipeline; Among them, the top of the bracket is also configured with a groove overlapping with the inclined hole, and a pad is installed inside the groove, and the pad partially blocks the inclined hole to form a detection hole; if the wafer on the bracket is in place, the wafer partially or completely blocks the detection hole to cause a pressure change in the pipeline.

2. The in-situ detection device according to claim 1, characterized in that: The groove is located outside the inclined hole, and the pad partially blocks the outer side of the inclined hole.

3. The in-situ detection device according to claim 1, wherein: The backing plate is provided with an auxiliary hole, and the auxiliary hole is arranged to match the position of the inclined hole.

4. The in-situ detection device according to claim 3, characterized in that: The auxiliary hole is a circular hole, which is arranged through the thickness direction of the backing plate and is located in the middle of the backing plate.

5. The in-situ detection device according to claim 3, characterized in that: The auxiliary hole is a waist-shaped hole or an elliptical hole, the pad is installed in the groove, and the short side of the auxiliary hole faces the center of the bracket.

6. The in-situ detection device according to claim 3, characterized in that: The auxiliary hole is an arc-shaped hole with a single-side opening, and is located at the edge of the backing plate.

7. The in-situ detection device according to claim 1, wherein: The material of the backing plate is the same as that of the top of the bracket, and the backing plate is made of wear-resistant plastic.

8. The in-situ detection device according to claim 1, wherein: The bracket is a disc-shaped structure, with multiple detection groups evenly distributed on the top, each detection group is configured with at least one detection hole; the detection holes configured in each detection group have different shapes and / or opening sizes.

9. A wafer exchange device, characterized in that: The invention comprises the on-site detection device according to any one of claims 1 to 8.

10. A wafer in-situ detection method, characterized in that: The on-site detection device according to any one of claims 1 to 8 comprises: S1, transport the medium source to the detection hole through the pipeline and the inclined hole; S2, when there is no wafer on the top of the bracket, read the pressure value P0 of the pressure sensor; S3, when there is a wafer on the top of the bracket and the wafer completely blocks the detection hole, read the pressure value P1 of the pressure sensor; S4, when the pressure P read by the pressure sensor corresponding to any detection group is greater than Pm, the wafer on the top of the bracket is in place, wherein P0<Pm<P1.

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