阅读说明：本技术 支撑环的量测方法 (Method for measuring support ring ) 是由 蔡永慧 谭秀文 苏亚青 于 2021-01-08 设计创作，主要内容包括：本申请公开了一种支撑环的量测方法,包括：通过晶圆的图像量测环形区域的宽度,该晶圆是经过太鼓减薄工艺减薄后的晶圆,环形区域是中心区域的边缘至边线的环形区域,中心区域是晶圆被减薄的区域,边线是晶圆的边缘弧线与晶圆所在平面的交点形成的线；根据宽度、晶圆的直径和中心区域的直径计算边缘区域的宽度,边缘区域是从环形区域的边缘至晶圆的边缘的环形区域；根据环形区域的宽度和边缘区域的宽度计算支撑环的宽度。本申请实施例中的边缘区域的宽度是通过量测计算得到,解决了相关技术中通过定值的边缘区域的宽度计算支撑环的宽度所导致的准确度较差的问题,提高了支撑环的宽度的计算的准确度。(The application discloses a method for measuring a support ring, which comprises the following steps: measuring the width of an annular area through an image of a wafer, wherein the wafer is thinned through a Taiko thinning process, the annular area is an annular area from the edge of a central area to an edge line, the central area is the thinned area of the wafer, and the edge line is a line formed by the intersection point of an arc line of the edge of the wafer and the plane of the wafer; calculating the width of an edge region according to the width, the diameter of the wafer and the diameter of the central region, wherein the edge region is an annular region from the edge of the annular region to the edge of the wafer; the width of the support ring is calculated from the width of the annular region and the width of the edge region. The width of the edge area in the embodiment of the application is obtained through measurement calculation, so that the problem of poor accuracy caused by calculating the width of the support ring through the width of the edge area with a fixed value in the related technology is solved, and the accuracy of calculation of the width of the support ring is improved.)

1. A method for measuring a support ring, comprising:

measuring the width of an annular area through an image of a wafer, wherein the wafer is thinned through a Taiko thinning process, the annular area is an annular area from the edge of a central area to an edge line, the central area is the thinned area of the wafer, and the edge line is a line formed by the intersection point of an edge arc line of the wafer and the plane of the lower surface of the wafer;

calculating a width of the edge region from an edge of the ring region to an edge of the wafer according to the width, the diameter of the wafer, and the diameter of the central region;

calculating the width of the support ring from the width of the annular region and the width of the edge region.

2. The method of claim 1, wherein the image of the wafer is an image of a cross-section of the wafer taken by a throughput device.

3. The method of claim 2, wherein the width of the annular region comprises a first annular width and a second annular width, the first annular width being a width of the annular region on one side of the cross-section and the second annular width being a width of the annular region on the other side of the cross-section.

4. The method of claim 3, wherein calculating the width of the edge region from the width, the diameter of the wafer, and the diameter of the center region comprises:

calculating the width of the edge region according to the first annular width, the second annular width, the diameter of the wafer and the diameter of the central region.

5. The method of claim 4, wherein calculating the width of the edge region from the first annular width, the second annular width, the diameter of the wafer, and the diameter of the center region comprises:

the width of the edge region is calculated according to the first annular width, the second annular width, the diameter of the wafer and the diameter of the central region by the following formula:

d＝(R-r-D1-D2)/2

wherein D is a width of the edge region, D1 is the first annular width, D2 is the second annular width, R is a diameter of the wafer, and R is a diameter of the center region.

6. The method of claim 4 or 5, wherein the width of the support ring comprises a first support ring width and a second support ring width, the first support ring width being a width of the support ring on one side of the cross-section and the second support ring width being a width of the support ring on the other side of the cross-section;

the calculating the width of the support ring according to the width of the annular region and the width of the edge region comprises:

calculating the first support ring width from the first annular width and the width of the edge region;

calculating the second support ring width from the second annular width and the width of the edge region.

7. The method of claim 6, wherein said calculating the first support ring width from the first annular width and the width of the edge region comprises:

calculating the first support ring width from the first annular width and the width of the edge region by the following formula:

Ring1＝D1+d

wherein Ring1 is the first support Ring width.

8. The method of claim 7, wherein calculating the second support ring width from the second annular width and the width of the edge region comprises:

calculating the second support ring width from the second annular width and the width of the edge region by the following equation:

Ring2＝D2+d

wherein Ring2 is the second support Ring width.

Technical Field

The application relates to the technical field of semiconductor manufacturing, in particular to a method for measuring a support ring in a Taiko thinning process.

Background

The drum thinning process is a thinning process developed by DISCO corporation of japan that does not thin the entire plane of the wafer, but only thins the central region of the wafer, the non-thinned edge region having a width of about 2 mm to 5 mm forming a support ring. The support ring can provide supporting force for the wafer, reduces the warpage of wafer, consequently, detects the width of support ring and can monitor grinding device's stability to ensure that the wafer attenuate concentricity does not have the skew, otherwise has the risk of later stage technology fragmentation.

Referring to fig. 1, there is shown a schematic cross-sectional view of a wafer after thinning by a drum thinning process; referring to fig. 2, a schematic top view of a thinned wafer by the drum thinning process is shown. As shown in fig. 1 and 2, after thinning by the drum thinning process, the central region 101 of the wafer 100 to be thinned is a circular region with a diameter P2P3, and the support ring 102 is an annular region of the wafer 100 except for the central region 101.

In the related art, the measurement method of the support ring includes: and shooting by a camera to obtain an image of the support ring, and measuring the image to obtain the width of the support ring. As shown in fig. 1 and 2, the support ring 102 includes an edge region 103 and an annular region 104, the edge region (level) 103 is arc-shaped, and it is difficult to measure the width of the edge region because the arc-shaped edge region 103 is difficult to focus, and therefore, in view of this, in the related art, the width of the support ring 102 is obtained by measuring the width of the annular region 104 in the image and adding a fixed value (the fixed value is a fixed width value of the edge region 103). For example, as shown in fig. 1 and 2, the distance D1 between P1P2 is obtained by measuring the wafer image, and the width of the support ring 102 is obtained by adding D1 to a constant value.

However, since the widths of the edge regions of different wafers are different, the measurement accuracy of the width of the support ring obtained by measuring the width of the ring-shaped region is poor.

Disclosure of Invention

The application provides a measuring method of a support ring, which can solve the problem of poor accuracy of the measuring method of the support ring provided in the related technology.

In one aspect, an embodiment of the present application provides a method for measuring a support ring, including:

measuring the width of an annular area through an image of a wafer, wherein the wafer is thinned through a Taiko thinning process, the annular area is an annular area from the edge of a central area to an edge line, the central area is the thinned area of the wafer, and the edge line is a line formed by the intersection point of an edge arc line of the wafer and the plane of the lower surface of the wafer;

calculating a width of the edge region from an edge of the ring region to an edge of the wafer according to the width, the diameter of the wafer, and the diameter of the central region;

calculating the width of the support ring from the width of the annular region and the width of the edge region.

Optionally, the image of the wafer is an image obtained by shooting a cross section of the wafer by the throughput equipment.

Optionally, the width of the annular region includes a first annular width and a second annular width, the first annular width being a width of the annular region on one side of the cross-section, and the second annular width being a width of the annular region on the other side of the cross-section.

Optionally, the calculating the width of the edge region according to the width, the diameter of the wafer, and the diameter of the central region includes:

calculating the width of the edge region according to the first annular width, the second annular width, the diameter of the wafer and the diameter of the central region.

Optionally, the calculating the width of the edge region according to the first annular width, the second annular width, the diameter of the wafer, and the diameter of the central region includes:

the width of the edge region is calculated according to the first annular width, the second annular width, the diameter of the wafer and the diameter of the central region by the following formula:

d＝(R-r-D1-D2)/2

wherein D is a width of the edge region, D1 is the first annular width, D2 is the second annular width, R is a diameter of the wafer, and R is a diameter of the center region.

Optionally, the width of the support ring comprises a first support ring width and a second support ring width, the first support ring width being the width of the support ring on one side of the cross section, the second support ring width being the width of the support ring on the other side of the cross section;

the calculating the width of the support ring according to the width of the annular region and the width of the edge region comprises:

calculating the first support ring width from the first annular width and the width of the edge region;

calculating the second support ring width from the second annular width and the width of the edge region.

Optionally, the calculating the first support ring width according to the first annular width and the width of the edge region includes:

calculating the first support ring width from the first annular width and the width of the edge region by the following formula:

Ring1＝D1+d

wherein Ring1 is the first support Ring width.

Optionally, the calculating the second support ring width according to the second annular width and the width of the edge region includes:

calculating the second support ring width from the second annular width and the width of the edge region by the following equation:

Ring2＝D2+d

wherein Ring2 is the second support Ring width.

The technical scheme at least comprises the following advantages:

the width of the annular area between the edge area and the central area of the wafer is measured from the image of the wafer, the width of the edge area is calculated according to the width, the diameter of the wafer and the diameter of the central area, and then the width of the support ring is calculated according to the width of the annular area and the width of the edge area.

Drawings

In order to more clearly illustrate the detailed description of the present application or the technical solutions in the prior art, the drawings needed to be used in the detailed description of the present application or the prior art description will be briefly introduced below, and it is obvious that 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 efforts.

FIG. 1 is a schematic cross-sectional view of a wafer after thinning by a Taiko thinning process;

FIG. 2 is a schematic top view of a wafer thinned by a Taiko thinning process;

fig. 3 is a flowchart of a method for measuring a support ring according to an exemplary embodiment of the present disclosure.

Detailed Description

The technical solutions in the present application will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

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 orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present application. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present application, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; the connection can be mechanical connection or electrical connection; the two elements may be directly connected or indirectly connected through an intermediate medium, or may be communicated with each other inside the two elements, or may be wirelessly connected or wired connected. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.

In addition, the technical features mentioned in the different embodiments of the present application described below may be combined with each other as long as they do not conflict with each other.

Referring to fig. 3, a flowchart of a method for measuring a support ring according to an exemplary embodiment of the present application is shown, the method including:

step 301, measuring the width of an annular region through an image of a wafer, where the wafer is thinned by the drum thinning process, the annular region is an annular region from the edge of a central region to an edge line, the central region is a thinned region of the wafer, and the edge line is a line formed by an intersection point of an arc line of the edge of the wafer and a plane where the wafer is located.

After the thump thinning process, the central region 101 of the wafer 100 is thinned, and the non-thinned region constitutes the support ring 102 of the wafer 100.

Illustratively, as shown in fig. 1 and 2, the edge of the wafer 100 is an arc having an intersection with a plane in which the lower surface of the wafer 100 lies, the intersection constituting a circular edge line, i.e., the dashed line between the edge of the wafer and the edge of the central region 101 in fig. 2.

The image of the wafer may be an image obtained by photographing a cross section of the wafer by the throughput device. For example, the image may be an image captured along a cross section cut along the cutting line P0P5 in fig. 2, which may be referred to fig. 1.

As shown in FIG. 1, the annular region 104 has a first annular width D1(P1P2) on one side of the cross-section and a second annular width D2(P3P4) on the other side of the cross-section, from which image measurements D1 and D2 can be obtained.

Step 302, calculate the width of the edge region from the edge of the ring region to the edge of the wafer based on the width, the diameter of the wafer, and the diameter of the center region.

For example, if the diameter R (P0P5) of the wafer 100 and the diameter R (P2P3) of the central region 101 are known, the width D (P0P1 and P4P5) of the edge region 103 can be calculated according to D1, D2, R and R as:

d＝(R-r-D1-D2)/2

step 303, calculating the width of the support ring according to the width of the annular region and the width of the edge region.

As shown in fig. 1 and 2, the widths of the support Ring 102 include a first support Ring width Ring1(P0P2) and a second support Ring width (P3P5), the first support Ring width Ring1 is a width of the support Ring 102 on one side of the cross-section of the wafer 100, and the second support Ring width Ring2 is a width of the support Ring 102 on the other side of the cross-section.

Illustratively, step 303 includes, but is not limited to: calculating a first support Ring width Ring1 from the first Ring width D1 and the width D of the edge region; a second support Ring width Ring2 is calculated from the second annular width D2 and the width D of the edge region.

Wherein the first support Ring width Ring1 may be calculated by the following equation:

Ring1＝D1+d

the second support Ring width Ring2 may be calculated by the following equation:

Ring2＝D2+d

in summary, in the embodiment of the present application, the width of the annular region between the edge region and the central region of the wafer is measured from the image of the wafer, the width of the edge region is calculated according to the width, the diameter of the wafer, and the diameter of the central region, and then the width of the support ring is calculated according to the width of the annular region and the width of the edge region.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications of this invention are intended to be covered by the scope of the invention as expressed herein.