Method for detecting cleaning capability of cleaning brush
By forming height difference streaks on the wafer surface and combining chemical mechanical grinding and defect detection, the problem of cleaning brush cleaning capacity monitoring is solved and the product yield is improved.
Patent Information
- Application Number
- CN202510558925.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-29
- Publication Date
- 2025-08-12
AI Technical Summary
The prior art is difficult to effectively monitor the cleaning capacity of the cleaning brush, resulting in a large number of grinding particles remaining on the wafer after cleaning, affecting product yield.
The wafer for monitoring is provided and a stripe with height difference is formed on its surface. It is cleaned by a chemical mechanical grinding process using a target cleaning brush, and the cleaning ability is judged in combination with defect detection.
Offline detection of cleaning brush cleaning capabilities is achieved, timely detection of insufficient cleaning capabilities and improving product yield.
Smart Images
Figure CN120468162A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of semiconductor manufacturing, and in particular to a method for detecting the cleaning ability of a cleaning brush. Background Art
[0002] Chemical Mechanical Polishing (CMP) is a crucial process in semiconductor manufacturing, mainly used to planarize the wafer surface.
[0003] After wafer grinding, a large amount of abrasive particles and other grinding byproducts accumulate on the wafer surface, requiring a cleaning brush to remove these particles. Currently, a cleaning brush with diluted ammonium hydroxide (NH4OH) is commonly used. The ammonium hydroxide flows through the center of the cleaning brush to rinse the brush and then flows outward from the brush holes on the cleaning brush onto the wafer, continuously removing the particles remaining on the wafer.
[0004] As the use time increases, the cleaning ability of the cleaning brush will gradually weaken. When the cleaning ability drops to a certain level, a large amount of abrasive particles will remain on the wafer after cleaning, resulting in low quality. Therefore, the cleaning ability of the cleaning brush needs to be monitored regularly. Summary of the Invention
[0005] The present application provides a method for detecting the cleaning ability of a cleaning brush, which can monitor the cleaning ability of the cleaning brush.
[0006] The present application embodiment provides a method for detecting the cleaning ability of a cleaning brush, comprising; Providing a monitoring wafer; forming a detection pattern on the surface of the monitoring wafer, wherein the detection pattern includes a plurality of parallel stripes, and there is a height difference between adjacent stripes; performing a chemical mechanical polishing process on the monitoring wafer; Cleaning the monitoring wafer using a target cleaning brush to be detected; Defect detection is performed on the monitoring wafer to determine the cleaning ability of the target cleaning brush.
[0007] In some embodiments, the detection pattern includes a plurality of first stripes and a plurality of second stripes that are distributed alternately, and there is a height difference between the first stripes and the second stripes.
[0008] In some embodiments, forming a detection pattern on the surface of the monitoring wafer includes: Depositing a first oxide layer and a silicon nitride layer in sequence on the surface of the monitoring wafer; forming a plurality of openings in the silicon nitride layer and the first oxide layer by photolithography and etching processes; depositing a second oxide layer in the opening; The silicon nitride layer is removed, and the remaining first oxide layer constitutes the first stripes, and the remaining second oxide layer constitutes the second stripes.
[0009] In some embodiments, the height difference between the first stripes and the second stripes is 30-50 nm.
[0010] In some embodiments, in the step of performing defect inspection on the monitoring wafer, a bright field defect scanning machine is used to perform defect inspection on the monitoring wafer.
[0011] In some embodiments, in the step of performing defect detection on the monitoring wafer, the wavelength of the incident light used is 260-320 nm, and an electric field perpendicular to the stripe direction is superimposed.
[0012] The technical solution of this application has at least the following advantages: 1. A monitoring wafer is provided, and several stripes with height differences are formed on its surface. Then, a chemical mechanical polishing process is performed on the monitoring wafer, and a target cleaning brush is used to clean the surface of the monitoring wafer that has undergone the chemical mechanical polishing process. During the cleaning process, due to the presence of several stripes with height differences, when the running direction of the target cleaning brush is perpendicular to the length direction of the stripes, if the cleaning ability of the target cleaning brush is poor, it is easier for abrasive particles to remain at the location where the height difference exists, making it easier to detect the defect of the target cleaning brush during the subsequent defect detection process. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.
[0014] Figure 1 is a flow chart of a method for detecting the cleaning ability of a cleaning brush provided by an exemplary embodiment of the present application; Figures 2 to 5 This is a structural schematic diagram of an exemplary embodiment of the present application for illustrating a process of forming first stripes and second stripes on a surface of a monitoring wafer; Figure 6 This is a schematic diagram provided by an exemplary embodiment of the present application for reflecting the position relationship between the target cleaning brush and the monitoring wafer during the cleaning process. DETAILED DESCRIPTION
[0015] The following is a clear and complete description of the technical solutions in this application in conjunction with the accompanying drawings. Obviously, the embodiments described are part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of this application.
[0016] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate the description of this application and simplify the description. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.
[0017] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal connections between two components; they can refer to wireless connections or wired connections. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.
[0018] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0019] This application provides a method for detecting the cleaning ability of a cleaning brush, referring to Figure 1 , the method comprises the following steps: S10: providing a monitoring wafer.
[0020] Exemplarily, a monitoring wafer is provided. For example, the monitoring wafer may be a 12-inch wafer.
[0021] S20: forming a detection pattern on the surface of the monitoring wafer, wherein the detection pattern includes a plurality of parallel stripes, and there is a height difference between adjacent stripes.
[0022] Exemplarily, a detection pattern is formed on the surface of the monitoring wafer, wherein the detection pattern includes a plurality of parallel stripes, and there is a height difference between adjacent stripes.
[0023] Furthermore, the detection pattern includes a plurality of first stripes and a plurality of second stripes that are distributed alternately, and there is a height difference between the first stripes and the second stripes.
[0024] Furthermore, the height difference between the first stripe and the second stripe may be 30-50 nm.
[0025] Further, refer to Figures 2 to 5 , this step may include the following processing flow: S201: depositing a first oxide layer and a silicon nitride layer in sequence on the surface of a monitoring wafer.
[0026] For example, refer to Figure 2 A monitoring wafer 1 is provided. First, a first oxide layer 2 and a silicon nitride layer 3 are sequentially grown on the surface of the monitoring wafer 1 through a furnace tube process.
[0027] S202: forming a plurality of openings in the silicon nitride layer and the first oxide layer through photolithography and etching processes.
[0028] For example, refer to Figure 3 Through photolithography and dry etching processes, a number of openings 4 are formed in the silicon nitride layer 3 and the first oxide layer 2, and the surface of the monitoring wafer 1 at the bottom of the openings 4 is exposed.
[0029] S203: depositing a second oxide layer in the opening.
[0030] For example, refer to Figure 4 , a high density plasma chemical vapor deposition process may be used to deposit a second oxide layer 5 , ie, an HDP oxide layer, in the opening.
[0031] S204: removing the silicon nitride layer, and the remaining first oxide layer forms first stripes, and the remaining second oxide layer forms second stripes.
[0032] For example, refer to Figure 5 A wet etching process can be used to remove the remaining silicon nitride layer 3 using a phosphoric acid solution. Thereafter, the remaining first oxide layer 2 constitutes a first stripe, and the remaining second oxide layer 5 constitutes a second stripe.
[0033] S30: performing a chemical mechanical polishing process on the monitoring wafer.
[0034] Exemplarily, a chemical mechanical polishing process is performed on the monitoring wafer on which the first stripes and the second stripes are formed.
[0035] S40: Cleaning the monitoring wafer using the target cleaning brush to be inspected.
[0036] For example, a target cleaning brush to be inspected is used to clean a monitoring wafer that has undergone a chemical mechanical polishing process. Figure 6 As shown, the monitoring wafer will also rotate. When the stripe direction is parallel to the rotation direction of the target cleaning brush, the cleaning effect is better. When the stripe direction is perpendicular to the rotation direction of the target cleaning brush, the positions where there are height differences in the stripes are more likely to retain grinding particles, thereby facilitating the monitoring of the target cleaning brush.
[0037] S50: Perform defect detection on the monitoring wafer to determine the cleaning ability of the target cleaning brush.
[0038] For example, after cleaning is completed, defect detection is performed on the monitoring wafer to determine the cleaning ability of the target cleaning brush.
[0039] Furthermore, in this step, a bright field defect scanning machine is used to perform defect detection on the monitoring wafer.
[0040] Furthermore, when using a brightfield defect scanner to inspect monitoring wafers for defects, the scanning method uses light with a wavelength of 260-320nm perpendicular to the surface of the monitoring wafer, and the defect status is determined by collecting the reflected light signal. Simultaneously, an electric field perpendicular to the stripe direction is superimposed to better collect defect signals at the bottom of the groove (i.e., the lower stripe surface).
[0041] The method for detecting the cleaning ability of a cleaning brush provided in an embodiment of the present application is to provide a monitoring wafer and form a plurality of stripes with height differences on its surface. Thereafter, a chemical mechanical polishing process is performed on the monitoring wafer, and a target cleaning brush is used to clean the surface of the monitoring wafer that has undergone the chemical mechanical polishing process. During the cleaning process, due to the presence of the plurality of stripes with height differences, when the running direction of the target cleaning brush is perpendicular to the length direction of the stripes, if the cleaning ability of the target cleaning brush is poor, abrasive particles are more likely to remain at the position where the height difference exists, which facilitates the detection of the defect of the target cleaning brush in the subsequent defect detection process, thereby realizing offline detection of the cleaning ability of the cleaning brush, and timely detecting the insufficient cleaning ability of the cleaning brush in the early stage, thereby improving the product yield in actual production.
[0042] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of this application.
Claims
1. A method for detecting the cleaning ability of a cleaning brush, characterized in that: include: Providing a monitoring wafer; forming a detection pattern on the surface of the monitoring wafer, wherein the detection pattern includes a plurality of parallel stripes, and there is a height difference between adjacent stripes; performing a chemical mechanical polishing process on the monitoring wafer; Cleaning the monitoring wafer using a target cleaning brush to be detected; Defect detection is performed on the monitoring wafer to determine the cleaning ability of the target cleaning brush.
2. The method for detecting the cleaning ability of a cleaning brush according to claim 1, characterized in that: The detection pattern includes a plurality of first stripes and a plurality of second stripes that are distributed in an alternating manner, and there is a height difference between the first stripes and the second stripes.
3. The method for detecting the cleaning ability of a cleaning brush according to claim 2, characterized in that: The forming of a detection pattern on the surface of the monitoring wafer includes: Depositing a first oxide layer and a silicon nitride layer in sequence on the surface of the monitoring wafer; forming a plurality of openings in the silicon nitride layer and the first oxide layer by photolithography and etching processes; depositing a second oxide layer in the opening; The silicon nitride layer is removed, and the remaining first oxide layer constitutes the first stripes, and the remaining second oxide layer constitutes the second stripes.
4. The method for detecting the cleaning ability of a cleaning brush according to claim 2, characterized in that: The height difference between the first stripe and the second stripe is 30-50 nm.
5. The method for detecting the cleaning ability of a cleaning brush according to claim 1, characterized in that: In the step of performing defect inspection on the monitoring wafer, a bright field defect scanning machine is used to perform defect inspection on the monitoring wafer.
6. The method for detecting the cleaning ability of a cleaning brush according to claim 1, characterized in that: In the step of performing defect detection on the monitoring wafer, the wavelength of the incident light used is 260-320 nm, and an electric field perpendicular to the stripe direction is superimposed.