Wafer defect determination and processing method, apparatus, wafer
By analyzing the distance between the wafer defect pattern and the center, the cause of the defect was determined. Ultrasonic vibration and rotation technology were used to solve the problem of wafer defect identification and avoidance, thereby improving wafer yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HANGZHOU FULLSEMI SEMICON CO LTD
- Filing Date
- 2022-12-31
- Publication Date
- 2026-06-16
AI Technical Summary
The lack of effective methods for identifying and avoiding wafer defects in existing technologies leads to low wafer yield.
By analyzing the distance between the wafer defect pattern and the center, the cause of the defect is determined. An ultrasonic vibration cleaning unit is used to rotate the wafer to avoid light pollution. The drive unit is used to drive the wafer to rotate to avoid light pollution of the defect pattern.
It improved wafer yield, reduced defects caused by light pollution, and enhanced the reliability of the processing.
Smart Images
Figure CN115863202B_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to wafer defect determination and processing technology, and more particularly to a method and apparatus for determining wafer defects, a wafer processing method and apparatus, and a wafer. Background Technology
[0002] Wafer fabrication involves multiple processes, each leading to different wafer defects. For example, in CMP (Chemical Metallurgy Processing), the PN junction of the wafer experiences electron flow under photon irradiation, causing Cu atoms to transfer from the P-doped end to the N-doped end, completing the P / N junction circuit and resulting in photo-assisted copper corrosion. This defect can be mitigated by reducing light exposure during polishing and cleaning. Currently, there is no effective method for identifying wafer defects, making many defects unavoidable and resulting in low wafer yield. Summary of the Invention
[0003] This disclosure provides a method and apparatus for determining wafer defects, a wafer processing method and apparatus, and a wafer, to at least solve the above-mentioned technical problems existing in the prior art.
[0004] According to a first aspect of this disclosure, a method for determining wafer defects is provided, comprising:
[0005] At least obtain the distribution information of defect patterns in each of the multiple wafers;
[0006] Based on the distribution information, the distance between the defect pattern in each wafer and the center of the wafer is determined;
[0007] Based on the distance between the defect pattern in each wafer and the center of the wafer, the cause of the defect corresponding to the defect pattern is determined.
[0008] In some possible implementations, determining the cause of the defect corresponding to the defect graphic includes:
[0009] The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. When the number of defect patterns that are equidistant from the center of the wafer exceeds a first set threshold, the defect pattern is determined to be caused by light pollution.
[0010] In some possible implementations, determining the cause of the defect corresponding to the defect graphic includes:
[0011] Count the number of defect patterns in each wafer that are at a distance from the center of the wafer;
[0012] When the number of defect patterns with a first equivalent distance exceeds a second set threshold, the defect patterns in the wafer are determined to be caused by the first light pollution.
[0013] When the number of defect patterns at a second distance exceeds a third set threshold, the defect patterns in the wafer are determined to be caused by a second light pollution; wherein the first distance and the second distance are different, and the light source of the first light pollution is different from the light source of the second light pollution.
[0014] In some possible implementations, the method further includes:
[0015] The location of the light pollution source is determined based on the distance between the defect pattern of the light pollution and the center of the wafer.
[0016] In some possible implementations, determining the cause of the defect corresponding to the defect graphic includes:
[0017] The location of the defect pattern on each wafer is determined based on the distance between the defect pattern and the center of the wafer.
[0018] If the wafer at this location has multiple defect patterns and the distribution of these multiple defect patterns is similar, it is determined to be a physical defect caused by the processing machine to the wafer.
[0019] In some possible implementations, determining the cause of the defect corresponding to the defect graphic includes:
[0020] The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. If the number of equidistant defect patterns is lower than a fourth set threshold, the defect patterns in the wafer are determined to be caused by water pollution.
[0021] According to a second aspect of this disclosure, a wafer fabrication method is provided, comprising:
[0022] During the process of metal etching or oxidation of the wafer to be processed using an ultrasonic vibration cleaning unit, the wafer to be processed is rotated.
[0023] In some possible implementations, rotating the wafer to be processed includes:
[0024] The rotational speed of the wafer to be processed is greater than or equal to 0.2 R / S.
[0025] According to a third aspect of this disclosure, an apparatus for determining wafer defects is provided, comprising:
[0026] The acquisition unit is used to acquire the distribution information of defect patterns of at least multiple wafers;
[0027] The first determining unit is used to determine the distance between the defect pattern in each wafer and the center of the wafer based on the distribution information;
[0028] The second determining unit is used to determine the cause of the defect corresponding to the defect pattern based on the distance between the defect pattern in each wafer and the center of the wafer.
[0029] In some possible implementations, the second determining unit is further configured to:
[0030] The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. When the number of defect patterns that are equidistant from the center of the wafer exceeds a first set threshold, the defect pattern is determined to be caused by light pollution.
[0031] In some possible implementations, the second determining unit is further configured to:
[0032] Count the number of defect patterns in each wafer that are at a distance from the center of the wafer;
[0033] When the number of defect patterns with a first equivalent distance exceeds a second set threshold, the defect patterns in the wafer are determined to be caused by the first light pollution.
[0034] When the number of defect patterns at a second distance exceeds a third set threshold, the defect patterns in the wafer are determined to be caused by a second light pollution; wherein the first distance and the second distance are different, and the light source of the first light pollution is different from the light source of the second light pollution.
[0035] In some possible implementations, the device further includes:
[0036] The third determining unit is used to determine the position of the light pollution source based on the distance between the defect pattern of the light pollution and the center of the wafer.
[0037] In some possible implementations, the second determining unit is further configured to:
[0038] The location of the defect pattern on each wafer is determined based on the distance between the defect pattern and the center of the wafer.
[0039] If the wafer at this location has multiple defect patterns and the distribution of these multiple defect patterns is similar, it is determined to be a physical defect caused by the processing machine to the wafer.
[0040] According to a fourth aspect of this disclosure, a wafer processing apparatus is provided, comprising:
[0041] The drive unit rotates the wafer to be processed during the process of metal etching or oxidation using the ultrasonic vibration cleaning unit.
[0042] In some possible implementations, the drive unit is further configured to:
[0043] The rotational speed of the wafer to be processed is greater than or equal to 0.2 R / S.
[0044] According to a fifth aspect of this disclosure, a wafer is provided, which is prepared by the wafer fabrication method described above.
[0045] The disclosed method and apparatus for determining wafer defects, wafer processing method and apparatus, and wafer, by analyzing the distribution information of defect patterns on multiple wafers, identify defect patterns caused by light pollution, and determine the location of the pollution source based on the defect pattern distribution of the wafer. Thus, when a light pollution source is identified, during wafer processing, the wafer to be processed is driven to rotate by a drive unit. Therefore, even with a pollution source present, because the wafer is constantly rotating, the pollution source will not illuminate a fixed position on the wafer, thus preventing light pollution defect patterns and improving the wafer product yield.
[0046] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description
[0047] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which:
[0048] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.
[0049] Figure 1 A flowchart illustrating a method for determining wafer defects according to an embodiment of this disclosure is shown;
[0050] Figure 2 A schematic diagram of a wafer defect pattern according to an embodiment of the present disclosure is shown;
[0051] Figure 3 A schematic diagram illustrating physical defects caused to a wafer by a machine according to an embodiment of the present disclosure is shown;
[0052] Figure 4 A flowchart of a wafer fabrication method according to an embodiment of the present disclosure is shown;
[0053] Figure 5 A schematic diagram of the composition structure of a wafer defect determination apparatus according to an embodiment of the present disclosure is shown;
[0054] Figure 6 A schematic diagram of the composition structure of a wafer processing apparatus according to an embodiment of the present disclosure is shown. Detailed Implementation
[0055] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0056] Figure 1 A flowchart illustrating a method for determining wafer defects according to an embodiment of this disclosure is shown, as follows: Figure 1 As shown, the method for determining wafer defects according to embodiments of this disclosure includes the following processing steps:
[0057] Step 101: Obtain at least the distribution information of defect patterns of each wafer in multiple wafers.
[0058] In wafer fabrication, chemical mechanical polishing (CMP) is an indispensable and important process. However, ultrasonic vibration in CMP can damage metals, especially Cu. Therefore, the ultrasonic cleaning unit (Meg) in Cu CMP is only used as a transfer unit. The wafer is stationary in the Meg. As a result, due to the stationary state of the wafer, a single area is exposed to sensor light for a long time, leading to wafer defects.
[0059] Another type of wafer defect is the copper corrosion defect in CMP, which is usually caused by high-pressure water splashing onto the wafer surface after polishing.
[0060] Figure 2 A schematic diagram of a wafer defect pattern according to an embodiment of the present disclosure is shown, such as... Figure 2 As shown in the embodiments of this disclosure, if the wafer defect pattern is caused by high-pressure water splashing onto the wafer surface after polishing, the distribution of the defect pattern is irregular and random. Even if multiple wafers are subjected to high-pressure water splashing, resulting in multiple defects, the shape and distribution position of each defect pattern are randomly distributed. However, for defect patterns caused by light pollution sources, since the position of the light source is fixed, the distance between the defect pattern and the center of the wafer is fixed when a wafer defect is caused by a light pollution source. That is, for the same light pollution source, the distance between the defect pattern and the center of the wafer is the same on multiple wafers. Therefore, based on the wafer defects caused by light pollution sources, the embodiments of this disclosure can determine which wafer defects are caused by light pollution sources.
[0061] During the wafer manufacturing process, physical defects may also occur on the wafers due to the aging of the equipment, such as by-products falling off or mechanical scratches. The characteristic of such defects is that they cause damage to all the fixed positions of the wafers passing through the equipment.
[0062] To address the various defects in wafers, it is necessary to identify the specific causes of these defects in order to improve the wafer processing technology and thereby increase the wafer processing yield.
[0063] Step 102: Determine the distance between the defect pattern in each wafer and the center of the wafer based on the distribution information.
[0064] Step 103: Based on the distance between the defect pattern in each wafer and the center of the wafer, determine the cause of the defect corresponding to the defect pattern.
[0065] In some implementation methods, determining the cause of a defect pattern specifically includes: accurately counting the number of defect patterns in each wafer that are equidistant from the center of the wafer; when the number of equidistant defect patterns exceeds a first preset threshold, the defect pattern is determined to be caused by light pollution. The first preset threshold can be 3; alternatively, it can be set as a ratio of the number of wafers counted, with the product of the number of wafers counted and the ratio serving as the preset threshold. In this case, the first preset threshold is a dynamic value. In this embodiment of the present disclosure, by analyzing different defects in multiple wafers, the specific location distribution of defect patterns in the wafers is determined. If the wafer defect is caused by light pollution, then the location of the light pollution source affecting the defects of all wafers is determined, i.e., the radius of the wafer defect patterns is the same. Therefore, by statistically analyzing the location distribution of multiple wafer defect patterns, the radius information of each wafer defect pattern is determined. When the number of defect patterns with the same radius exceeds the preset threshold, the defect pattern can be determined to be caused by light pollution.
[0066] As an alternative method, determining the cause of a defect pattern can also include: counting the number of defect patterns on each wafer that are at a distance equivalent to the center of the wafer; when the number of defect patterns at a first distance exceeds a second preset threshold, determining that the defect pattern on the wafer is caused by a first type of light pollution; when the number of defect patterns at a second distance exceeds a third preset threshold, determining that the defect pattern on the wafer is caused by a second type of light pollution; wherein the first distance and the second distance are different, and the light source of the first light pollution is different from the light source of the second light pollution. The third preset threshold can be set to 3, the second preset threshold can be set to 4, etc., or it can be set as a ratio of the number of wafers counted, with the product of the number of wafers counted and this ratio serving as the preset threshold. In this example, when there is more than one light pollution source, the number and distribution of light pollution sources can be quickly determined by counting the radii of the defect patterns. That is, when there are multiple light pollution sources, the radii of the defect patterns on the wafers are different, thus allowing the identification of multiple light pollution sources.
[0067] In some implementations, the method further includes determining the location of the light pollution source based on the distance between the defect pattern caused by the light pollution and the center of the wafer. Specifically, the distance between the light pollution source and the center of the wafer can be determined based on the radius of the defect pattern caused by the light pollution, thereby determining the location of the light pollution source.
[0068] As one implementation method, determining the cause of the defect corresponding to the defect pattern may also include: determining the location of the defect pattern on the wafer based on the distance between the defect pattern in each wafer and the center of the wafer; determining that there are multiple defect patterns on the wafer at that location and that the distribution positions of these multiple defect patterns are similar, and determining that they are physical defects caused by the processing machine to the wafer.
[0069] Figure 3 A schematic diagram illustrating physical defects caused to a wafer by a machine according to an embodiment of this disclosure is shown, such as... Figure 3 As shown, the main cause of fixed-position defects during wafer fabrication is physical defects on the wafers due to machine aging, such as byproducts falling off and mechanical scratches. These problems can damage the fixed positions of all wafers passing through the machine. Scanning revealed fixed-position defects on the wafers. Figure 3 Although the defect pattern at position #01 differs from other wafer defect patterns, it is centrally symmetrical to other defects caused by the equipment. That is, the defect pattern is located at a fixed position on the wafer, and there are multiple defect patterns at this fixed position with similar distributions. For physical defects caused by equipment aging, the equipment can be replaced to avoid mechanical scratches on the wafer caused by the equipment.
[0070] In some implementations, determining the cause of a defect pattern may further include: counting the number of defect patterns in each wafer that are equidistant from the center of the wafer; and determining that the defect pattern in the wafer is caused by water contamination when the number of equidistant defect patterns is less than a fourth preset threshold. Here, the fourth preset threshold can be 2, meaning that if the number of equidistant defect patterns is less than 2, the wafer defect pattern is considered to be caused by randomness.
[0071] This disclosure embodiment analyzes and determines defects caused by wafers, thereby minimizing wafer defects during wafer processing and improving wafer product yield.
[0072] Figure 4 A flowchart of a wafer fabrication method according to an embodiment of the present disclosure is shown, as follows: Figure 4 As shown, the wafer fabrication method of this disclosure includes the following processing steps:
[0073] Step 401: During the process of metal etching or oxidation of the wafer to be processed using the ultrasonic vibration cleaning unit, the wafer to be processed is rotated.
[0074] In this embodiment of the present disclosure, during the process of metal etching or oxidation of the wafer to be processed using the ultrasonic vibration cleaning unit, the rotational speed of the wafer to be processed is greater than or equal to 0.2 R / S. In this embodiment of the present disclosure, the rotational speed of the wafer to be processed can be adjusted according to the specific processing scenario, such as being set to 0.3 R / S, 0.4 R / S, 0.5 R / S, 0.8 R / S, 1 R / S, 1.5 R / S, etc.
[0075] In this embodiment of the present disclosure, when a light pollution source is identified, the wafer to be processed is driven to rotate by a driving unit during the wafer processing. In this way, even if there is a pollution source, the pollution source will not illuminate a fixed position on the wafer and cause light pollution defect patterns because the wafer is constantly rotating, thereby improving the product yield of the wafer.
[0076] In this embodiment of the invention, an effective source of light pollution is found in the copper chemical mechanical polishing process of wafers. For example, by analyzing the location of the defect pattern and combining it with the structure of each unit of the machine, an effective source of light pollution is found where the light from the Meg wafer sensor indicator shines on the surface of the wafer, which is a copper corrosion defect. Wafer defects caused by light pollution are avoided by rotating the wafer.
[0077] Figure 5 A schematic diagram of the composition structure of a wafer defect determination apparatus according to an embodiment of the present disclosure is shown, as follows: Figure 5 As shown, the wafer defect determination apparatus of this disclosure includes:
[0078] Acquisition unit 50 is used to acquire at least the distribution information of defect patterns of each wafer in multiple wafers;
[0079] The first determining unit 51 is used to determine the distance between the defect pattern in each wafer and the center of the wafer based on the distribution information;
[0080] The second determining unit 52 is used to determine the cause of the defect corresponding to the defect pattern based on the distance between the defect pattern in each wafer and the center of the wafer.
[0081] In some possible implementations, the second determining unit 52 is further configured to:
[0082] The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. When the number of defect patterns that are equidistant from the center of the wafer exceeds a first set threshold, the defect pattern is determined to be caused by light pollution.
[0083] In some possible implementations, the second determining unit 52 is further configured to:
[0084] Count the number of defect patterns in each wafer that are at a distance from the center of the wafer;
[0085] When the number of defect patterns with a first equivalent distance exceeds a second set threshold, the defect patterns in the wafer are determined to be caused by the first light pollution.
[0086] When the number of defect patterns at a second distance exceeds a third set threshold, the defect patterns in the wafer are determined to be caused by a second light pollution; wherein the first distance and the second distance are different, and the light source of the first light pollution is different from the light source of the second light pollution.
[0087] exist Figure 5 Based on the wafer defect determination apparatus shown, the wafer defect determination apparatus of this disclosure embodiment further includes:
[0088] The third unit ( Figure 5 (Not shown in the image), used to determine the location of the light pollution source based on the distance between the defect pattern of the light pollution and the center of the wafer.
[0089] In some possible implementations, the second determining unit 52 is further configured to:
[0090] The location of the defect pattern on each wafer is determined based on the distance between the defect pattern and the center of the wafer.
[0091] If the wafer at this location has multiple defect patterns and the distribution of these multiple defect patterns is similar, it is determined to be a physical defect caused by the processing machine to the wafer.
[0092] In some possible implementations, the second determining unit 52 is further configured to:
[0093] The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. If the number of equidistant defect patterns is lower than a fourth set threshold, the defect patterns in the wafer are determined to be caused by water pollution.
[0094] In an exemplary embodiment, the acquisition unit 50, the first determination unit 51, the second determination unit 52, the third determination unit, etc., may be implemented by one or more central processing units (CPUs), graphics processing units (GPUs), application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components.
[0095] Regarding the apparatus in the above embodiments, the specific manner in which each module and unit performs its operations has been described in detail in the embodiments related to the method, and will not be elaborated upon here.
[0096] Figure 6 A schematic diagram of the composition structure of a wafer processing apparatus according to an embodiment of the present disclosure is shown, as follows: Figure 6 As shown, the wafer processing apparatus of this disclosure includes:
[0097] The drive unit 60 rotates the wafer to be processed during the process of metal etching or oxidation using the ultrasonic vibration cleaning unit.
[0098] In some possible implementations, the drive unit 60 is further configured to:
[0099] The rotational speed of the wafer to be processed is greater than or equal to 0.2 R / S.
[0100] In an exemplary embodiment, the driving unit 60 may be implemented by one or more central processing units (CPUs), graphics processing units (GPUs), application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components.
[0101] Regarding the apparatus in the above embodiments, the specific manner in which each module and unit performs its operations has been described in detail in the embodiments related to the method, and will not be elaborated upon here.
[0102] According to embodiments of this disclosure, this disclosure also describes a wafer prepared by the wafer processing method of the foregoing embodiments.
[0103] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.
[0104] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.
Claims
1. A method for determining wafer defects, characterized in that, The method includes: At least obtain the distribution information of defect patterns in each of the multiple wafers; Based on the distribution information, the distance between the defect pattern in each wafer and the center of the wafer is determined; Based on the distance between the defect pattern in each wafer and the center of that wafer, the cause of the defect corresponding to the defect pattern is determined. The determination of the defect cause corresponding to the defect image includes: Count the number of defect patterns in each wafer that are at a distance from the center of the wafer; When the number of defect patterns with a first equivalent distance exceeds a second set threshold, the defect patterns in the wafer are determined to be caused by the first light pollution. When the number of defect patterns at a second distance exceeds a third set threshold, the defect patterns in the wafer are determined to be caused by a second light pollution; wherein the first distance and the second distance are different, and the light source of the first light pollution is different from the light source of the second light pollution.
2. The method according to claim 1, characterized in that, The method further includes: The location of the light pollution source is determined based on the distance between the defect pattern of the light pollution and the center of the wafer.
3. The method according to claim 1, characterized in that, The determination of the defect cause corresponding to the defect image includes: The location of the defect pattern on each wafer is determined based on the distance between the defect pattern and the center of the wafer. If the wafer at this location has multiple defect patterns and the distribution of these multiple defect patterns is similar, it is determined to be a physical defect caused by the processing machine to the wafer.
4. The method according to claim 1, characterized in that, The determination of the defect cause corresponding to the defect image includes: The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. If the number of equidistant defect patterns is lower than a fourth set threshold, the defect patterns in the wafer are determined to be caused by water pollution.
5. A wafer fabrication method, characterized in that, The method includes: When a source of light pollution is identified using the wafer defect determination method as described in claim 1, the wafer to be processed is rotated during the metal etching or oxidation process of the wafer to be processed using an ultrasonic vibration cleaning unit.
6. The method according to claim 5, characterized in that, The process of rotating the wafer to be processed includes: The rotational speed of the wafer to be processed is greater than or equal to 0.2 r / s.
7. A device for determining wafer defects, characterized in that, The device includes: The acquisition unit is used to acquire the distribution information of defect patterns of at least multiple wafers; The first determining unit is used to determine the distance between the defect pattern in each wafer and the center of the wafer based on the distribution information; The second determining unit is used to determine the cause of the defect corresponding to the defect pattern based on the distance between the defect pattern in each wafer and the center of the wafer. The determination of the defect cause corresponding to the defect image includes: Count the number of defect patterns in each wafer that are at a distance from the center of the wafer; When the number of defect patterns with a first equivalent distance exceeds a second set threshold, the defect patterns in the wafer are determined to be caused by the first light pollution. When the number of defect patterns at a second distance exceeds a third set threshold, the defect patterns in the wafer are determined to be caused by a second light pollution; wherein the first distance and the second distance are different, and the light source of the first light pollution is different from the light source of the second light pollution.
8. The apparatus according to claim 7, characterized in that, The device further includes: The third determining unit is used to determine the position of the light pollution source based on the distance between the defect pattern of the light pollution and the center of the wafer.
9. The apparatus according to claim 7, characterized in that, The second determining unit is further configured to: The location of the defect pattern on each wafer is determined based on the distance between the defect pattern and the center of the wafer. If the wafer at this location has multiple defect patterns and the distribution of these multiple defect patterns is similar, it is determined to be a physical defect caused by the processing machine to the wafer.
10. The apparatus according to claim 7, characterized in that, The second determining unit is further configured to: The number of defect patterns in each wafer that are equidistant from the center of the wafer is counted. If the number of equidistant defect patterns is lower than a fourth set threshold, the defect patterns in the wafer are determined to be caused by water pollution.
11. A wafer processing apparatus, characterized in that, The device includes: The drive unit, when a source of light pollution is determined using the wafer defect determination device as described in claim 7, rotates the wafer to be processed during the metal etching or oxidation process performed by the ultrasonic vibration cleaning unit.
12. The apparatus according to claim 11, characterized in that, The driving unit is further configured to drive the wafer to be processed at a rotational speed greater than or equal to 0.2 r / s.
13. A wafer, characterized in that, The wafer is prepared by the method described in claim 5 or 6.