Method for grinding and cleaning wafer back under advanced process node
By employing chemical mechanical polishing and wet chemical cleaning methods, the lithography machine malfunction caused by particles on the crystal back surface was resolved, resulting in improved flatness of the crystal back surface and optimized production capacity.
Patent Information
- Application Number
- CN202511066169.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-30
- Publication Date
- 2025-11-07
AI Technical Summary
Existing technologies are insufficient for wet cleaning of the crystal back surface at advanced process nodes, leading to abnormal focus spots on lithography equipment and affecting production capacity.
The back of the crystal is polished using a chemical mechanical polishing process, followed by wet chemical cleaning with hydrochloric acid and hydrogen peroxide or a mixture of ammonia and hydrogen peroxide, and then rinsed with deionized water. Finally, it is dried.
It effectively removes particles from the back surface of the crystal, improves surface flatness, avoids focus spots during the photolithography process, and enhances production efficiency.
Smart Images
Figure CN120914085A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of semiconductor technology, in particular to a method for backside grinding and cleaning in advanced process nodes. BACKGROUND
[0002] In the case of more advanced semiconductor manufacturing process technology, the precision of photolithography is higher and higher, and the flatness and defects of the wafer backside become more and more important, which can cause abnormal fluctuations of a certain focus spot of a subsequent photolithography machine, resulting in an alarm of the photolithography machine, and the photolithography needs to rework the wafer with the focus spot, which greatly wastes the production capacity.
[0003] Through analysis of the wafer backside pattern and the slice, the focus spot is mainly caused by the wafer backside surface particle defects and surface protrusions as shown in the figure. Figure 1 The wafer backside wet cleaning used in the prior art is not enough to remove the wafer backside surface particles while achieving a certain flatness of the wafer backside surface, thus the occurrence of the focus spot is inevitable. SUMMARY
[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a method for backside grinding and cleaning in advanced process nodes, which solves the problem that the wafer backside wet cleaning in the prior art is not enough to remove the wafer backside surface particles while achieving a certain flatness of the wafer backside surface.
[0005] To achieve the above-mentioned purpose and other related purposes, the present application provides a method for backside grinding and cleaning in advanced process nodes, comprising:
[0006] Step one, polishing treatment is performed on the wafer backside to improve the flatness of the wafer backside surface;
[0007] Step two, cleaning treatment is performed on the wafer backside to remove the wafer backside surface particle defects.
[0008] Preferably, the polishing treatment on the wafer backside is performed by a chemical mechanical grinding process.
[0009] Preferably, the method for cleaning treatment on the wafer backside is to first perform wet chemical cleaning and then perform deionized water rinsing.
[0010] Preferably, the cleaning solution for wet chemical cleaning includes a mixture of hydrochloric acid and hydrogen peroxide or a mixture of ammonia and hydrogen peroxide.
[0011] Preferably, after step two is performed, drying treatment is performed on the wafer surface.
[0012] Preferably, after the drying treatment is performed, photolithography treatment is performed on the wafer.
[0013] As described above, the method for backside grinding and cleaning of advanced process nodes provided by the present application has the following beneficial effects: the particles on the backside surface are removed while the backside surface reaches a certain flatness, and the appearance of Focus Spot is avoided. BRIEF DESCRIPTION OF DRAWINGS
[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the specific embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.
[0015] Figure 1 Electronic photos showing the protrusions and particle defects on the backside surface;
[0016] Figure 2 Flowchart showing the method for backside grinding and cleaning of advanced process nodes provided by the embodiments of the present application;
[0017] Figure 3 Comparison chart showing the removal rates of protrusions and particle defects on the backside surface by the methods for backside grinding and cleaning of advanced process nodes provided by the prior art and the embodiments of the present application. DETAILED DESCRIPTION
[0018] The embodiments of the present application will be described in detail below through specific, concrete examples, and those skilled in the art can easily understand other advantages and effects of the present application from the disclosure of the present specification. The present application can also be implemented or applied through other different specific embodiments, and each detail in the present specification can be modified or changed based on different views and applications without departing from the spirit of the present application.
[0019] The technical solutions in the present application will be described in detail below with reference to the drawings, and obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0020] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description and cannot be understood as indicating or implying relative importance.
[0021] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements, it can be wireless connection, or it can be wired connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0022] 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 there is no conflict.
[0023] Please refer to Figure 2 , which shows the flowchart of the method for backgrinding and cleaning of wafers under advanced process nodes provided by the embodiments of the present application.
[0024] As Figure 2 shown, the method for backgrinding and cleaning of wafers under advanced process nodes comprises:
[0025] Step one, polishing the wafer back to improve the flatness of the wafer back surface;
[0026] Step two, cleaning the wafer back to remove the particle defects on the wafer back surface.
[0027] In step one, the wafer back is polished by a chemical mechanical polishing process.
[0028] In step two, the method for cleaning the wafer back is to first implement wet chemical cleaning and then implement deionized water rinsing, wherein the cleaning solution for wet chemical cleaning comprises a mixture of hydrochloric acid and hydrogen peroxide or a mixture of ammonia and hydrogen peroxide.
[0029] After step two is implemented, the wafer surface is dried. As Figure 3As shown, compared with the prior art, the method for backside grinding and cleaning of wafers in advanced process nodes provided by the present application has no fluctuation in the removal rate of particle defects and surface protrusions in each area of the full surface of the wafer. Therefore, the wafer back surface is cleaned and the wafer back surface reaches a certain flatness, thereby avoiding the appearance of Focus Spot during subsequent photolithography processing of the wafer. The present application effectively overcomes various shortcomings in the prior art and has high industrial utilization value.
[0030] It should be noted that the diagrams provided in the present embodiment only illustrate the basic concept of the present application in a schematic manner, and only show the components related to the present application in the diagrams, rather than being drawn according to the number, shape and size of the components when actually implemented. The actual implementation of each component may be arbitrarily changed in terms of type, number and proportion, and the component layout type may also be more complex.
[0031] The above embodiments only illustratively explain the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical idea disclosed by the present application should be covered by the claims of the present application.
Claims
1. A method for cleaning of backgrinding of advanced process nodes, characterized in that, The method comprises: Step one, polishing the wafer back to improve the flatness of the wafer back surface; Step two, cleaning the wafer back to remove the particle defects on the wafer back surface.
2. The method of claim 1, wherein, The wafer back is polished by a chemical mechanical polishing process.
3. The method of claim 1, wherein, The method for cleaning the wafer back is to first perform a wet chemical cleaning and then perform a deionized water rinsing.
4. The method of claim 3, wherein, The cleaning solution for the wet chemical cleaning comprises a mixture of hydrochloric acid and hydrogen peroxide or a mixture of ammonia and hydrogen peroxide.
5. The method of claim 1, wherein, After the step two is performed, the wafer surface is dried.
6. The method of claim 5, wherein, After the drying is performed, the wafer is subjected to a photolithography process.
Citation Information
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