Novel polishing pad and wafer polishing machine table
By designing a new polishing pad with multiple nested grinding areas, the process from coarse to fine polishing on a single polishing pad is realized, solving the problem of low wafer polishing efficiency in the prior art, and significantly improving production efficiency.
Patent Information
- Application Number
- CN202420087078.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-12
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2034-01-12
AI Technical Summary
In the prior art, wafer polishing efficiency is low, and multiple polishing disks are required for coarse and fine casting, resulting in a reduced production efficiency.
A new type of polishing pad is designed, including multiple nested grinding areas, each grinding area has different roughness. By implementing the process from rough to fine polishing on a single polishing pad, the required number of polishing disks is reduced.
The full polishing process of the wafer is achieved on a single polishing pad, which greatly improves the polishing efficiency, reduces the processing steps of the wafer to be processed, and improves the production efficiency.
Smart Images
Figure CN222289775U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of semiconductor processing, in particular to a novel polishing pad and a wafer polishing machine. Background Art
[0002] With the changes of the times, large-scale integration of circuits has become a necessary condition for the continued development of society, and the processing and manufacturing of semiconductor wafers, the carrier of integrated circuits, has also received more and more attention from all walks of life.
[0003] In the production process of wafers, surface polishing of wafers is a necessary process step. The existing method of polishing wafers is to use a polishing pad to perform the overall polishing process. When it comes to certain metal processes, the overall polishing is specifically divided into two steps of chemical mechanical polishing. The first step is rough polishing to remove most of the metal layer on the surface of the wafer, and the second step is fine polishing to repair the surface damage of the wafer. However, the polishing pads used in the two steps have different materials, roughness and other conditions, so two polishing discs are required for the process, which greatly reduces production efficiency.
[0004] Therefore, how to improve the polishing efficiency of wafers has become an urgent problem to be solved by technical personnel in this field. Utility Model Content
[0005] The utility model aims to provide a novel polishing pad and a wafer polishing machine to solve the problem of low wafer polishing efficiency in the prior art.
[0006] In order to solve the above technical problems, the utility model provides a novel polishing pad, comprising a plurality of mutually nested grinding areas;
[0007] The roughness of each grinding area is different.
[0008] Optionally, in the novel polishing pad, the roughness of the plurality of grinding regions gradually decreases from the inside to the outside.
[0009] Optionally, in the novel polishing pad, the novel polishing pad only includes a plurality of annular grinding areas.
[0010] Optionally, in the novel polishing pad, the novel polishing pad comprises a circular rough grinding area and an annular fine grinding area;
[0011] The annular fine grinding area is sleeved outside the circular rough grinding area.
[0012] Optionally, in the novel polishing pad, the width of the annular fine grinding area is the same as the radius of the circular rough grinding area.
[0013] Optionally, in the novel polishing pad, the thickness of the circular rough grinding area ranges from 1.3 mm to 1.5 mm, including end points.
[0014] Optionally, in the novel polishing pad, the density of the circular rough abrasive area ranges from 430 grams per cubic centimeter to 470 grams per cubic centimeter, including endpoint values.
[0015] Optionally, in the novel polishing pad, the compression ratio of the circular rough grinding area ranges from 6.3 to 6.6, including endpoint values.
[0016] Optionally, in the novel polishing pad, the thickness of the annular fine grinding area ranges from 0.8 mm to 1.0 mm, including end value.
[0017] A wafer polishing machine, comprising a polishing head, a polishing head motion assembly and a novel polishing pad as described above;
[0018] The polishing head moving assembly is connected to the polishing head to drive the polishing head to move between different grinding areas of the novel polishing pad.
[0019] The new polishing pad provided by the utility model includes a plurality of grinding areas nested with each other; each of the grinding areas has a different degree of roughness. The new polishing pad provided by the utility model includes a plurality of grinding areas nested with each other. In actual use, the wafer polishing machine can drive the wafer to be processed to move between different grinding areas, so as to complete polishing of different fineness on a single polishing pad. In other words, using the new polishing pad provided by the utility model, each polishing disc on the wafer polishing machine can independently complete the entire process of wafer grinding, and the polishing of a wafer to be processed no longer needs to be processed by multiple polishing discs, thereby greatly improving the polishing efficiency of the wafer. The utility model also provides a wafer polishing machine with the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0021] Figure 1 A schematic top view of a specific embodiment of the new polishing pad provided by the utility model;
[0022] Figure 2A three-dimensional structural schematic diagram of a specific implementation of the new polishing pad provided by the utility model;
[0023] Figure 3 A cross-sectional schematic diagram of a specific implementation of the new polishing pad provided by the utility model.
[0024] In the figure, it includes 01-grinding area, 01A-circular rough grinding area, and 01B-annular fine grinding area. DETAILED DESCRIPTION
[0025] In order to enable those skilled in the art to better understand the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention.
[0026] The core of the utility model is to provide a new type of polishing pad, a structural schematic diagram of a specific implementation method is shown in FIG. Figure 1 As shown, it is called specific embodiment 1, including a plurality of mutually nested grinding areas 01;
[0027] The roughness of each grinding area 01 is different.
[0028] Figure 1 The grinding area 01 is a ring and a circle nested together, and the grinding area 01 can be a closed loop shape, an open loop shape, a square shape, or a circle. Taking the ring-shaped grinding area 01 as an example, the corresponding open loop shape is a grinding area 01 without a closed ring. Since the polishing pad is placed on the polishing disk and rotates at a high speed during use, even if the grinding area 01 is an open loop shape, it does not affect the grinding use.
[0029] As a preferred embodiment, the roughness of the plurality of grinding areas 01 gradually decreases from the inside to the outside.
[0030] The higher the roughness, the thicker the corresponding polishing pad material. The roughness of the grinding area 01 gradually decreases from the inside to the outside. Figure 2 and Figure 3 , Figure 2 is a schematic diagram of a three-dimensional structure of a specific embodiment of the novel polishing pad, Figure 3 is the corresponding cross-sectional diagram. Figure 3In the embodiment, the circular rough grinding area 01A and the annular fine grinding area 01B are uniformly labeled as grinding area 01, which means that the material of the surface of the new polishing pad will become thinner from the center to the edge, so that the grinding liquid in the grinding and polishing process can be better discharged. On the contrary, if the inner side of the polishing pad, that is, the center, has the lowest roughness and the roughness gradually increases from the inside to the outside, the surface morphology of the polishing pad will be thin in the middle and thick at the edge, forming a bowl-shaped surface, making it difficult to discharge the grinding liquid, causing pollution and reducing the polishing effect.
[0031] As another specific embodiment, the novel polishing pad only includes a plurality of annular grinding areas 01. In this preferred embodiment, the innermost closed area of the annular grinding area 01 is not used as the grinding area 01, but all grinding areas 01 are set as annular grinding areas 01, and the grinding areas 01 used are limited to mutually nested annular areas, which not only simplifies the production of the novel polishing pad, but also facilitates the design of the movement route planning of the wafer to be processed between the grinding areas 01 with different roughness, making the design process simpler, facilitating the subsequent program design, and simplifying the grinding and polishing process in disguise.
[0032] As a specific embodiment, the novel polishing pad includes a circular rough grinding area 01A and an annular fine grinding area 01B;
[0033] The annular fine grinding area 01B is sleeved outside the circular rough grinding area 01A.
[0034] This preferred embodiment is as follows Figure 1 As shown, the new polishing pad is divided into an inner circular area (i.e., the circular rough grinding area 01A) and an outer annular area (i.e., the annular fine grinding area 01B). This structure is easiest to produce, and the grinding route design is simple and has a high fault tolerance.
[0035] Furthermore, the width of the annular fine grinding area 01B is the same as the radius of the circular rough grinding area 01A.
[0036] The same radius and width are equivalent to that in the process of grinding and polishing, on a straight line segment from the center to the edge of the novel polishing pad, the line segments corresponding to different grinding roughness have the same length, which can further simplify the movement route design of the wafer to be processed in subsequent grinding and polishing.
[0037] As a preferred embodiment, the thickness of the circular rough grinding area 01A ranges from 1.3 mm to 1.5 mm, including endpoint values, such as any one of 1.30 mm, 1.44 mm or 1.50 mm; the density of the circular rough grinding area 01A ranges from 430 g / cm3 to 470 g / cm3, including endpoint values, such as any one of 430.0 g / cm3, 454.8 g / cm3 or 470.0 g / cm3; the compression ratio of the circular rough grinding area 01A ranges from 6.3 to 6.6, including endpoint values, such as any one of 6.30, 6.44 or 6.60; the hardness of the circular rough grinding area 01A ranges from 85 to 92, including endpoint values, such as any one of 85.0, 89.6 or 92.0.
[0038] The thickness of the annular fine grinding area 01B ranges from 0.8 mm to 1.0 mm, including endpoint values, such as any one of 0.80 mm, 0.91 mm or 1.00 mm; the density of the annular fine grinding area 01B ranges from 0.36 g / cm3 to 0.38 g / cm3, including endpoint values, such as any one of 0.360 g / cm3, 0.374 g / cm3 or 0.380 g / cm3; the hardness of the annular fine grinding area 01B ranges from 65 to 69, including endpoint values, such as any one of 65.0, 67.1 or 69.0; the compression ratio of the annular fine grinding area 01B ranges from 4.4 to 4.6, including endpoint values, such as any one of 4.40, 4.52 or 4.60.
[0039] The above parameter ranges are obtained after a large number of theoretical calculations and actual tests. Within the above ranges, the new polishing pad can have better working stability and longer service life.
[0040] The new polishing pad provided by the utility model includes a plurality of mutually nested grinding areas 01; each of the grinding areas 01 has a different degree of roughness. The new polishing pad provided by the utility model includes a plurality of mutually nested grinding areas 01. In actual use, the wafer polishing machine can drive the wafer to be processed to move between different grinding areas 01, so as to complete polishing of different fineness on a single polishing pad. In other words, using the new polishing pad provided by the utility model, each polishing disc on the wafer polishing machine can independently complete the whole process of wafer grinding, and the polishing of a wafer to be processed no longer needs to be processed by multiple polishing discs, thereby greatly improving the polishing efficiency of the wafer.
[0041] The utility model also provides a wafer polishing machine, which comprises a polishing head, a polishing head motion assembly and a novel polishing pad as described in any one of the above;
[0042] The polishing head moving assembly is connected to the polishing head to drive the polishing head to move between different grinding areas 01 of the novel polishing pad.
[0043] The wafer to be processed is fixed in the polishing head, and the polishing head moves between different grinding areas 01 of the novel polishing pad. For other technical details, please refer to the above text, and the utility model will not be elaborated here.
[0044] like Figure 1 As shown, the polishing pad is divided into two areas, namely the annular fine grinding area 01B and the circular rough grinding area 01A.
[0045] When rough polishing and fine polishing are required, the wafer to be processed is first ground in the circular rough polishing area 01A to remove the film layer. After the rough polishing is completed, the polishing head is raised and the two grinding areas 01 are cleaned by the dresser and deionized water of the wafer polishing machine.
[0046] The polishing head moves to the annular fine grinding area 01B, and then fine polishing is performed. After the fine polishing process is completed, the wafer is transferred to the cleaning part for brushing. The current mainstream wafer polishing machine using chemical mechanical grinding generally has a structure of 4 polishing discs. If the method in the prior art can only process two wafers at a time, the new method can process 4 wafers to be processed at a time, greatly improving the efficiency of grinding and polishing.
[0047] The wafer polishing machine provided by the utility model comprises a polishing head, a polishing head moving assembly and a new type of polishing pad as described above; the polishing head moving assembly is connected to the polishing head to drive the polishing head to move between different grinding areas 01 of the new type of polishing pad. The new type of polishing pad comprises a plurality of grinding areas 01 nested with each other; the roughness of each grinding area 01 is different. The new type of polishing pad provided by the utility model comprises a plurality of grinding areas 01 nested with each other. In actual use, the wafer polishing machine can drive the wafer to be processed to move between different grinding areas 01, so as to complete polishing of different fineness on a single polishing pad. In other words, by using the new type of polishing pad provided by the utility model, each polishing disc on the wafer polishing machine can independently complete the whole process of wafer grinding, and the polishing of a wafer to be processed no longer needs to be processed by multiple polishing discs, thereby greatly improving the polishing efficiency of the wafer.
[0048] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.
[0049] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.
[0050] The above is a detailed introduction to the new polishing pad and wafer polishing machine provided by the utility model. This article uses specific examples to illustrate the principle and implementation method of the utility model. The description of the above embodiments is only used to help understand the method and core idea of the utility model. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the utility model, the utility model can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the utility model.
Claims
1. A new type of polishing pad, characterized in that: It includes multiple grinding areas nested in each other; The roughness of each grinding area is different; The surface of the novel polishing pad becomes thinner from the center to the edge; The novel polishing pad comprises a circular rough grinding area and an annular fine grinding area; The annular fine grinding area is sleeved outside the circular rough grinding area; The width of the annular fine grinding area is the same as the radius of the circular rough grinding area; The thickness of the circular coarse grinding area ranges from 1.3 mm to 1.5 mm, including the end values; The density of the circular coarse grinding area ranges from 430 grams per cubic centimeter to 470 grams per cubic centimeter, including endpoint values; The compression ratio of the circular coarse grinding area ranges from 6.3 to 6.6, including the endpoint values; The annular fine grinding area has a thickness in the range of 0.8 mm to 1.0 mm, both inclusive.
2. The novel polishing pad according to claim 1, characterized in that: The roughness of the plurality of grinding areas gradually decreases from the inside to the outside.
3. The novel polishing pad according to claim 1, characterized in that: The novel polishing pad comprises only a plurality of annular abrasive regions.
4. A wafer polishing machine, characterized in that: The wafer polishing machine comprises a polishing head, a polishing head motion assembly and a novel polishing pad as claimed in any one of claims 1 to 3; The polishing head moving assembly is connected to the polishing head to drive the polishing head to move between different grinding areas of the novel polishing pad.