An endless belt large plate for improving flatness of a wafer

Abstract

The utility model discloses a kind of annular belt large plates for improving wafer flatness, it is related to wafer polishing equipment field, including polishing large plate and the annular belt for adjusting large plate type, the annular band is installed on the upper surface of the large plate with the same center, the cross section of the annular band is ladder-shaped or isosceles trapezoidal shape.Because the cross section of the annular band is ladder-shaped or isosceles trapezoidal shape, when wafer is polished, the inner end side of wafer first contacts annular band, the edge of wafer is contacted annular band later, gap or passage for facilitating polishing liquid to flow to the inner end side of wafer is reserved between wafer and annular band, effectively reduce the unevenness of polishing liquid distribution, reduce the mechanical action of wafer edge when polishing treatment, improve the uniformity of wafer surface removal rate, improve the final flatness of wafer.

Description

Technical Field

[0001] This utility model relates to the field of wafer polishing equipment, and more particularly to an annular belt disc for improving wafer flatness. Background Technology

[0002] The wafer fabrication process mainly includes the following six steps: Step 1, chamfering the wafer (or other items requiring flatness processing); Step 2, grinding the chamfered wafer surface; Step 3, fixing the back of the ground wafer onto a polishing ceramic disk using an adhesive or absorbent pad; Step 4, attaching a suitable polishing pad to the surface of the polishing disk; Step 5, moving the polishing ceramic disk so that the front of the wafer on the polishing ceramic disk comes into contact with the polishing pad, then causing a relative displacement between the polishing ceramic disk and the polishing disk, and simultaneously spraying polishing fluid onto the polishing pad, so that the polishing disk polishes the front of the wafer; Step 6, removing the polished wafer from the polishing ceramic disk and removing the adhesive from the back of the wafer; Step 7, cleaning the wafer.

[0003] like Figure 4 As shown, existing polishing pads have extremely high flatness, but this flatness presents some problems. For example, in step five above, the edges of the wafer can fully contact the fresh polishing slurry, while the center or inner side of the wafer cannot, affecting the final polishing level of the wafer product. Current research on the uniformity of polishing slurry distribution mainly focuses on the grooving of the polishing pad surface. The fabrication of grooves on the polishing pad surface introduces other related problems.

[0004] Therefore, this invention provides a new solution by optimizing the shape of the polishing disk to reduce the uneven distribution of polishing fluid and decrease the mechanical action on the wafer edge during polishing, thereby improving the uniformity of the removal rate on the wafer surface. Utility Model Content

[0005] The purpose of this invention is to provide a ring-shaped large disk for improving wafer flatness, which solves the problem that existing polishing disks have limited uniformity of polishing slurry distribution on the wafer surface and limited uniformity of mechanical action on the inner and outer sides of the wafer, resulting in large differences in removal rates at different parts of the wafer.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] This utility model provides an annular belt for improving wafer flatness, including a polishing disc and an annular belt for adjusting the shape of the polishing disc. The annular belt is installed concentrically on the upper surface of the polishing disc, and the cross-section of the annular belt is stepped or isosceles trapezoidal.

[0008] Optionally, the annular belt is composed of multiple annular films, each with a different annular area.

[0009] Optionally, the height of the annular strip ranges from 10 micrometers to 200 micrometers.

[0010] Optionally, the ratio of the height of each annular membrane in the annular belt to the difference between the outer and inner diameters of that annular membrane is in the range of 0.15E-5 to 2.6E-4.

[0011] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0012] Because the cross-section of the annular belt is stepped or isosceles trapezoidal, when polishing the wafer, the inner end of the wafer contacts the annular belt first, and the edge of the wafer contacts the annular belt later. A gap or channel is reserved between the wafer and the annular belt to facilitate the flow of polishing fluid to the inner end of the wafer, which effectively reduces the uneven distribution of polishing fluid, reduces the mechanical action on the edge of the wafer during polishing, improves the uniformity of the removal rate on the wafer surface, and improves the final flatness of the wafer. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings.

[0014] Figure 1 This is a front view of the annular belt disk of this utility model used to improve wafer flatness;

[0015] Figure 2 This is a cross-sectional view of the annular strip disk used to improve wafer flatness according to this invention. Figure 1 ;

[0016] Figure 3 This is a cross-sectional view of the annular strip disk used to improve wafer flatness according to this invention. Figure 2 ;

[0017] Figure 4 This is a schematic diagram of the principle of traditional wafer polishing equipment.

[0018] Explanation of reference numerals in the attached diagram: 1. Large disc; 2. Circular belt; 3. Polishing disc; 4. Polishing ceramic disc; 5. Wafer; 6. Polishing fluid. Detailed Implementation

[0019] To make the technical problem to be solved, the technical solution, and the beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this utility model and are not intended to limit this utility model.

[0020] like Figures 1-3As shown, an annular belt for improving wafer flatness includes a large disk 1 and an annular belt 2 for polishing the wafer. The annular belt 2 is installed concentrically on the upper surface of the large disk 1, and the cross-section of the annular belt 2 is stepped or isosceles trapezoidal.

[0021] Among them, the annular band 2 is adsorbed onto the large disk 1.

[0022] Specifically, the annular belt 2 is composed of multiple annular membranes, each with a different annular area.

[0023] Specifically, the annular membrane is made using a polishing belt.

[0024] Specifically, the height of the annular belt 2 ranges from 10 micrometers to 200 micrometers.

[0025] Specifically, the ratio of the height of each annular membrane in the annular belt 2 to the difference between the outer and inner diameters of that annular membrane ranges from 0.15E-5 to 2.6E-4.

[0026] In this invention, since the cross-section of the annular belt 2 is stepped or isosceles trapezoidal, when polishing the wafer 5, the inner end of the wafer 5 contacts the annular belt 2 first, and the edge of the wafer 5 contacts the annular belt 2 later. A gap or channel is reserved between the wafer 5 and the annular belt 2 to facilitate the flow of polishing liquid to the inner end of the wafer, which effectively reduces the uneven distribution of polishing liquid 6, reduces the mechanical action on the edge of the wafer 5 during polishing, improves the uniformity of the removal rate on the surface of the wafer 5, and improves the final flatness of the wafer 5.

[0027] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0028] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A ring-shaped strip for improving wafer flatness, characterized in that: It includes a large disc (1) and an annular belt (2) for adjusting the shape of the polishing disc. The annular belt (2) is installed on the upper surface of the large disc (1) with the same center. The cross section of the annular belt (2) is stepped or isosceles trapezoidal.

2. The annular belt disk for improving wafer flatness according to claim 1, characterized in that: The annular band (2) is composed of multiple annular membranes, each with a different annular area.

3. The annular belt for improving wafer flatness according to claim 1, characterized in that: The height of the annular strip (2) ranges from 10 micrometers to 200 micrometers.

4. The annular belt for improving wafer flatness according to claim 1, characterized in that: The ratio of the height of each annular membrane in the annular band (2) to the difference between the outer and inner diameters of the annular membrane is in the range of 0.15E-5 to 2.6E-4.

Images