CN213858719U

CN213858719U - Grinding structure

Info

Publication number: CN213858719U
Application number: CN202021991470.6U
Authority: CN
Inventors: 郝雨筱
Original assignee: Yangtze Memory Technologies Co Ltd
Current assignee: Yangtze Memory Technologies Co Ltd
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2021-08-03
Anticipated expiration: 2030-09-11

Abstract

The embodiment of the present disclosure discloses a grinding structure, including: a gasket, the gasket surface comprising a groove and a protrusion; a flexible abrasive sheet covering the surface of the pad on which the grooves and the protrusions are provided.

Description

Grinding structure

Technical Field

The embodiment of the disclosure relates to the technical field of semiconductors, in particular to a grinding structure.

Background

In semiconductor fabrication, various microfabrication techniques are being researched and developed. Such as chemical mechanical polishing techniques. By polishing, the semiconductor structure can be planarized.

However, when the surface of the semiconductor structure subjected to warp deformation is ground and thinned, due to the warp deformation of the surface, the grinding speed of the grinding device for different areas of the surface is different, the consistency of thinning is reduced, and the product quality is further reduced.

SUMMERY OF THE UTILITY MODEL

In view of the above, an embodiment of the present disclosure provides a polishing structure, including:

a gasket, the gasket surface comprising a groove and a protrusion;

a flexible abrasive sheet covering the surface of the pad on which the grooves and the protrusions are provided.

In some embodiments, the gasket surface comprises a plurality of said grooves; wherein, the distances between the adjacent grooves which are arranged in parallel are equal;

and/or the presence of a gas in the gas,

said gasket surface comprising a plurality of said protrusions; wherein the distances between adjacent protrusions arranged in parallel are equal.

In some embodiments, when the gasket surface comprises a plurality of said grooves, the width of at least two of said grooves is different;

and/or the presence of a gas in the gas,

when the gasket surface includes a plurality of the projections, widths of at least two of the projections are different.

In some embodiments, the width of the groove comprises at least one of: 0.5 cm; 1.2 cm; 1.4 cm; 1.8 cm;

and/or the presence of a gas in the gas,

the width of the protrusion is at least one of: 0.5 cm; 1.2 cm; 1.4 cm; 1.8 cm.

In some embodiments, the shim is circular;

the grooves and the protrusions are arranged in parallel in the diameter direction parallel to the circle.

In some embodiments, the groove is located in a first region of the gasket surface;

the protrusion is positioned on the second area of the surface of the gasket; wherein the second region is symmetrical to the first region about the center of the circle.

In some embodiments, when the gasket surface includes a plurality of the grooves, the width of the groove relatively closer to the center of the circle is greater than the width of the groove relatively farther from the center of the circle;

and/or the presence of a gas in the gas,

when the shim surface includes a plurality of the protrusions, the width of the protrusions relatively closer to the center of the circle is greater than the width of the protrusions relatively farther from the center of the circle.

In some embodiments, the plurality of grooves taper in width along the first direction;

and/or the presence of a gas in the gas,

the width of the plurality of protrusions gradually decreases along a first direction;

the first direction points from the circle center to the circular edge and is parallel to the diameter of the circle.

In some embodiments, the abrasive structure further comprises:

a first marking layer located between the groove and the abrasive sheet; wherein the thickness of the first mark layer is smaller than the depth of the groove;

a second indicia layer positioned between the protrusions and the abrasive sheet, wherein the second indicia layer is a different color than the first indicia layer.

In some embodiments, when the shim surface includes at least two of the grooves of different widths, the first indicia layer covering the grooves of different widths is a different color;

and/or the presence of a gas in the gas,

when the shim surface includes at least two of the projections of different widths, the color of the second indicia layer covering the projections of different widths is different.

The grinding structure that this disclosed embodiment provided, through the surface be provided with recess and bellied gasket, and combine the flexible abrasive sheet that covers this gasket, when the abrasive sheet contacts with the semiconductor structure who treats to grind, the semiconductor structure takes place the recess or the arch of bending deformation region can form good contact through the gasket with the abrasive sheet, other regions that do not take place bending deformation region accessible gasket surface except recess and arch in this semiconductor structure form good contact with the abrasive sheet, and then guarantee that the region homoenergetic that the semiconductor structure needs to grind forms good contact with the abrasive sheet, be favorable to improving the uniformity of attenuate.

Moreover, the grooves and the protrusions are arranged on the surfaces of the gaskets, the front and back surfaces of the semiconductor structure which is bent (protruded and sunken) can be thinned by the grinding structure, the grinding structure does not need to be replaced in the thinning process, and the grinding efficiency is improved while the thinning consistency is improved.

Furthermore, by introducing the spacer, sandpaper and the like in the prior art can be continuously used as the polishing sheet, and the compatibility with the related art is strong. And the grinding and thinning of the semiconductor structure are realized by combining the gasket and the grinding sheet, so that the hardware cost is low.

Drawings

FIG. 1 is a schematic diagram illustrating a semiconductor structure in accordance with an exemplary embodiment;

FIG. 2 is a front view of an abrasive structure according to an exemplary embodiment;

FIG. 3a is a schematic diagram illustrating a polishing structure for polishing a semiconductor structure in accordance with an exemplary embodiment;

FIG. 3b is a schematic diagram illustrating another polishing structure for polishing a semiconductor structure in accordance with an exemplary embodiment;

FIG. 4 is a top view of a gasket shown in accordance with an exemplary embodiment.

Detailed Description

The technical solutions of the present disclosure will be further explained in detail with reference to the drawings and examples. While exemplary implementations of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The present disclosure is more particularly described in the following paragraphs with reference to the accompanying drawings by way of example. Advantages and features of the present disclosure will become apparent from the following description and claims. It is to be noted that the drawings are in a very simplified form and are not to precise scale, which is merely for the purpose of facilitating and distinctly claiming the embodiments of the present disclosure.

It is to be understood that the meaning of "on … …," "over … …," and "over … …" in this disclosure should be read in the broadest manner such that "on … …" not only means that it is "on" something without intervening features or layers therebetween (i.e., directly on something), but also includes the meaning of being "on" something with intervening features or layers therebetween.

In the disclosed embodiment, the term "a is connected to B" includes A, B where a is connected to B in contact with each other, or A, B where a is connected to B in a non-contact manner with other components interposed between the two.

In the embodiments of the present disclosure, the terms "first", "second", and the like are used for distinguishing similar objects, and are not necessarily used for describing a particular order or sequence.

The technical means described in the embodiments of the present disclosure may be arbitrarily combined without conflict.

In the related art, when a semiconductor structure is ground, the semiconductor structure may be brought into contact with abrasive paper, and the semiconductor structure may be rubbed by relative movement between the semiconductor structure and the abrasive paper to thin the semiconductor structure.

As shown in fig. 1, the chip may also be warped due to the stress inside the chip. Alternatively, the substrate and the chip package may be subjected to warpage. When a semiconductor structure is warped and deformed, the direct thinning of the semiconductor structure with sandpaper is prone to non-uniformity. For example, the thinning speed of the convex area of the semiconductor structure is higher, and the thinning speed of the concave area of the semiconductor structure is lower, so that the thinned semiconductor structure has the phenomenon of uneven material thickness and poorer surface flatness.

In addition, in the related art, the surface flatness can be corrected by local thinning, but the efficiency is low, and the integrity of the semiconductor structure can be damaged, so that the performance of the semiconductor structure is damaged, and the quality is reduced.

It is understood that the semiconductor structure includes, but is not limited to, a memory chip, a packaged substrate and chip, and the like.

Fig. 2 is a schematic diagram illustrating an abrasive structure 100 according to an exemplary embodiment. Referring to fig. 2, the abrasive structure 100 includes:

a gasket 110, wherein the surface of the gasket 110 comprises a groove 111 and a protrusion 112;

a flexible abrasive sheet 120 covering the surface of the pad 110 provided with the grooves 111 and the protrusions 112.

The constituent material of the gasket 110 includes a rigid material. Thus, the polishing pad 120 can be supported well, and the polishing structure 100 can ensure a good polishing effect on the semiconductor structure to be polished.

The gasket 110 includes first and second oppositely disposed surfaces. The groove 111 and the protrusion 112 may be provided on the first surface or the second surface.

It should be noted that when the grooves 111 and the protrusions 112 are disposed on the first surface, the second surface is a flat surface, and the polishing sheet 120 is relatively close to the first surface and relatively far from the second surface, so that when the semiconductor structure to be polished is thinned by the polishing structure 100, the second surface can provide a flat surface contacting with the worktable, which is beneficial to ensure the consistency of thinning.

Similarly, when the grooves 111 and the protrusions 112 are disposed on the second surface, the first surface is a flat surface, and the abrasive sheet 120 is relatively close to the second surface and relatively far from the first surface.

The flexible abrasive sheet 120 is deformed along the shape of the grooves 111 and the protrusions 112 of the pad 110 by an external force, so that the abrasive sheet 120 is closely attached to the surface of the pad 110 where the grooves 111 and the protrusions 112 are formed. The flexible abrasive sheet 120 may include: and (7) sand paper.

It will be appreciated that when the polishing structure 100 is used to polish a semiconductor structure to be thinned, the semiconductor structure is in contact with the polishing sheet 120, the polishing sheet 120 being located between the semiconductor structure and the surface of the pad 110 provided with the grooves 111 and protrusions 112.

It should be noted that when the semiconductor structure to be polished is in contact with the polishing sheet 120, if the deformed region of the semiconductor structure is a convex region, the convex region can be polished by using the region of the polishing sheet 120 covering the groove 111.

Specifically, as shown in fig. 3a, the surface to be polished of the semiconductor structure may include a convex region, the convex region may cause the flexible polishing sheet 120 in contact therewith to be bent and deformed into the groove 111 in the pad 110, and the groove 111 may support the polishing sheet 120 so that the convex region can be brought into good contact with the polishing sheet 120. Therefore, the grinding sheet 120 can uniformly cover the deformed surface of the semiconductor structure, and the area of the semiconductor structure needing to be ground can be ensured to be in good contact with the grinding sheet 120, thereby being beneficial to improving the consistency of thinning.

Similarly, if the deformed region of the semiconductor structure is a recessed region, the recessed region can be polished by covering the region on the protrusion 112 with a polishing sheet 120, as shown in fig. 3 b. The protrusions 112 on the pad 110 can cause the flexible polishing sheet 120 in contact therewith to bend and deform toward the recessed areas in the semiconductor structure and support the polishing sheet 120 in good contact with the recessed areas in the semiconductor structure. Therefore, the grinding sheet 120 can uniformly cover the deformed surface of the semiconductor structure, and the area of the semiconductor structure needing to be ground can be ensured to be in good contact with the grinding sheet 120, thereby being beneficial to improving the consistency of thinning.

It will be understood that when the front side of the semiconductor structure includes raised regions, the locations of the reverse side, which is generally opposite the front side, corresponding to the raised regions, include recessed regions. According to the embodiment of the disclosure, the surface of the gasket 110 is provided with the groove 111 and the protrusion 112, the front and back surfaces of the semiconductor structure which is bent (protruded and recessed) can be thinned by the grinding structure 100 provided by the disclosure, the grinding structure 100 does not need to be replaced in the thinning process, and the grinding efficiency is improved while the thinning consistency is improved.

It is understood that for the flat area of the semiconductor structure without warpage deformation, the flat surface outside the grooves 111 and the protrusions 112 can be provided by the pad 110, and the supporting grinding sheet 120 makes good contact with the flat area of the semiconductor structure to ensure the consistency of thinning.

Illustratively, the polishing pads 120 in the polishing structure 100 are replaceable, e.g., different grit sizes of the polishing pads 120 may be replaced depending on the desired polishing thickness. It is emphasized that the polishing sheets 120 and the pads 110 are independent from each other, and the polishing structure 100 can be formed by matching the same pad 110 with polishing sheets 120 of different particle sizes.

The embodiment of the present disclosure, through the introduction of the pad 110, may continue to use sandpaper or the like in the prior art as the polishing sheet 120, which is highly compatible with the related art. Moreover, the combination of the gasket 110 and the grinding sheet 120 realizes grinding and thinning of the semiconductor structure, and the hardware cost is low.

In some embodiments, referring to FIG. 4, the surface of the shim 110 includes a plurality of grooves 111; wherein, the distances between the adjacent grooves 111 arranged in parallel are equal;

and/or the presence of a gas in the gas,

the surface of the gasket 110 includes a plurality of protrusions 112; wherein the distances between adjacent protrusions 112 arranged in parallel are equal.

Illustratively, referring to fig. 4, the surface of the gasket 110 includes four grooves 111 arranged in parallel in the direction parallel to the X axis, which are a first groove 111a, a second groove 111b, a third groove 111c and a fourth groove 111d in sequence, and the distance between two adjacent grooves is a first distance.

Referring to fig. 4, the surface of the gasket 110 may further include four protrusions 112, a first protrusion 112a, a second protrusion 112b, a third protrusion 112c, and a fourth protrusion 112d, which are sequentially arranged in parallel in the X-axis direction. The distance between two adjacent parallel arranged bulges is a second distance. The second pitch may be the same as or different from the first pitch.

In the embodiment of the disclosure, by providing the plurality of grooves 111 and/or the protrusions 112 on the surface of the gasket 110, it is beneficial to increase the area of the area where the gasket 110 can be used for being combined with the polishing sheet 120 to polish and thin the warpage deformation area of the semiconductor structure, so that the polishing structure 100 can simultaneously utilize different grooves 111 or protrusions 112 to polish different semiconductor structures, and the polishing efficiency is improved.

In some embodiments, when the surface of the gasket 110 includes a plurality of grooves 111, the widths of at least two of the grooves 111 are different;

and/or the presence of a gas in the gas,

when the surface of the gasket 110 includes a plurality of protrusions 112, at least two of the protrusions 112 have different widths.

Illustratively, when the depths of the grooves 111 are the same, the degree of concavity of different grooves 111 may be changed by changing the width of the grooves 111. For example, when the width of the groove 111 is larger, the degree of concavity of the groove 111 is smaller.

The width of the groove 111 includes at least one of: 0.5 cm; 1.2 cm; 1.4 cm; 1.8 cm.

When the degree of the upward projection of the convex region generated by the semiconductor warpage deformation is higher in matching with the degree of the depression of the groove 111 of the pad 110, which covers the polishing sheet 120, the better the contact between the polishing sheet 120 and the convex region is, which is beneficial to improving the consistency of thinning.

Compared with the method that the grinding sheet 120 is combined with the grooves 111 with the same width to grind the semiconductor structures with different convex degrees, the method that at least two grooves 111 with different widths are arranged on the surface of the gasket 110 and the grinding sheet 120 and the grooves 111 with different widths are combined to grind the semiconductor structures with different convex degrees can improve the thinning consistency of the grinding structure 100 on the semiconductor structures with different convex degrees, and further improve the quality of the ground semiconductor structures.

In addition, by providing the grooves 111 with different widths, the semiconductor structure can be thinned first by the polishing sheet 120 covering the grooves 111 with a larger width, and then the regions that need to be locally corrected can be thinned by the grooves 111 with a smaller width.

For example, when a first type of sample having a width of 1.2 cm and a length of 1.8 cm or a second type of sample having a width of 1.4 cm and a length of 1.8 cm is thinned, the first type of sample may be thinned by using the grooves 111 or the protrusions 112 having a width of 1.2 cm, 1.4 cm or 1.8 cm to increase the thinning speed. Then, local thinning is performed using a groove 111 or a protrusion 112 having a width of 0.5 cm to ensure uniformity of thinning.

Illustratively, when the height of the protrusions 112 is the same, the protrusion of the protrusions 112 on the surface of the gasket 110 can be varied by varying the width of the protrusions 112. For example, when the height of the protrusion 112 is the same, the greater the width of the protrusion 112, the less the protrusion of the protrusion 112.

The width of the protrusion 112 is at least one of: 0.5 cm; 1.2 cm; 1.4 cm; 1.8 cm.

When the degree of concavity of the depressed region generated by the warp deformation of the semiconductor is higher in matching with the degree of convexity of the protrusions 112 of the pad 110 covering the polishing sheet 120, the polishing sheet 120 is better in contact with the depressed region, which is advantageous for improving the consistency of thinning.

Compared with the method of polishing the semiconductor structures with different recessed degrees by using the polishing sheet 120 and combining the protrusions 112 with the same width, the method of polishing the semiconductor structures with different recessed degrees by using the polishing sheet 120 and the grooves 111 with different widths can improve the thinning consistency of the polishing structure 100 to the semiconductor structures with different recessed degrees and further improve the quality of the polished semiconductor structures by arranging at least two protrusions 112 with different widths on the surface of the pad 110 and combining the polishing sheet 120 and the grooves 111 with different widths to polish the semiconductor structures with different raised degrees.

In summary, in the embodiments of the disclosure, the at least two grooves 111 and/or the at least two protrusions 112 with different widths are disposed on the surface of the pad 110, so that the thinning consistency of the polishing structure 100 for semiconductor structures with different deformation degrees can be improved, and the quality of the polished semiconductor structure can be further improved.

In addition, in a certain range, the width of the groove 111 or the protrusion 112 is increased, and the thinning speed is also increased. Therefore, the width of the groove 111 or the width of the protrusion 112 can be set according to actual requirements.

In some embodiments, referring to FIG. 4, the shim 110 is circular;

the grooves 111 and the protrusions 112 are arranged in parallel in a direction parallel to the diameter of the circle.

Illustratively, the groove 111 is located in a first region 110a of the surface of the gasket 110.

A protrusion 112 located at the second region 110b of the surface of the gasket 110; wherein the second area is symmetrical to the first area about the center (O point) of the circle.

In some embodiments, when the surface of the gasket 110 includes a plurality of grooves 111, the width of the groove 111 relatively close to the center of the circle is greater than the width of the groove 111 relatively far from the center of the circle;

and/or the presence of a gas in the gas,

when the surface of the gasket 110 includes a plurality of protrusions 112, the width of the protrusion 112 relatively close to the center of the circle is greater than the width of the protrusion 112 relatively far from the center of the circle.

In some embodiments, along the first direction, the width of the plurality of grooves 111 gradually decreases;

and/or the presence of a gas in the gas,

in the first direction, the width of the plurality of protrusions 112 gradually decreases;

For example, when the widths of the grooves 111 on the surface of the gasket 110 are different, the widths of the grooves 111 arranged in parallel along the first direction may gradually decrease along the first direction.

The width difference between two adjacent grooves 111 may be the same or different. For example, the first groove 111a and the second groove 111b have a first width difference therebetween, the second groove 111b and the third groove 111c have a second width difference therebetween, and the first width difference may be the same as or different from the second width difference. Thus, the semiconductor structure that can be thinned by the grinding structure 100 can be widened while the thinning consistency is ensured to be good, and the requirements of various samples are met.

When the widths of the protrusions 112 on the surface of the gasket 110 are different, the widths of the protrusions 112 arranged in parallel along the first direction may gradually decrease along the first direction.

The width difference between two adjacent protrusions 112 may be the same or different. For example, the first protrusion 112a has a third width difference between the second protrusions 112b, the second protrusion 112b has a fourth width difference between the third protrusions 112c, and the third width difference may be the same as or different from the fourth width difference. Thus, the semiconductor structure that can be thinned by the grinding structure 100 can be widened while the thinning consistency is ensured to be good, and the requirements of various samples are met.

In some embodiments, the abrasive structure 100 further comprises:

a first marking layer (not shown) located between the groove 111 and the abrasive sheet 120; wherein the thickness of the first mark layer is less than the depth of the groove 111;

and a second indicia layer (not shown) between the protrusions 112 and the abrasive sheet 120, wherein the second indicia layer is a different color than the first indicia layer.

In the embodiment of the present disclosure, through setting up the first mark layer and the second mark layer of different colours, recess 111 and arch 112 are distinguished to the accessible colour, so, when carrying out the attenuate operation to semiconductor structure, need not the operator and distinguish recess 111 and arch 112 through other detection means, just can distinguish through the colour, and the mode is simple, is favorable to improving operating efficiency.

In some embodiments, when the surface of the shim 110 includes at least two grooves 111 of different widths, the color of the first indicia layer covering the grooves 111 of different widths is different;

and/or the presence of a gas in the gas,

when the surface of the shim 110 includes at least two protrusions 112 of different widths, the color of the second indicia layer covering the protrusions 112 of different widths is different.

It should be noted that, when the width difference between the grooves 111 with different widths is small, the difficulty of distinguishing the grooves 111 with different widths by naked eyes is large, errors are easy to occur, and the improvement of the thinning consistency is not facilitated. This disclosed embodiment covers the recess 111 of different width through the first mark layer that sets up different colours, and the recess 111 of different width is distinguished to the accessible colour, and the mode is simple, is favorable to improving operating efficiency.

In addition, the grooves 111 with different widths are covered by the first mark layers with different colors, so that the accuracy of selecting the grooves 111 with the required widths is high, and the thinning effect is better.

Similarly, when the width difference between the protrusions 112 with different widths is small, the difficulty of distinguishing the protrusions 112 with different widths by naked eyes is large, errors are easy to occur, and the improvement of the thinning consistency is not facilitated. According to the embodiment of the present disclosure, the second mark layers with different colors are arranged to cover the protrusions 112 with different widths, so that the protrusions 112 with different widths can be distinguished through colors, the method is simple, and the operation efficiency is improved.

In addition, the second mark layers with different colors are arranged to cover the bulges 112 with different widths, so that the selection accuracy of the bulges 112 with the required widths is high, and the thinning effect is better.

In the embodiments provided in the present disclosure, it should be understood that the disclosed apparatus and system may be implemented in other ways. The above description is only for the specific embodiments of the present disclosure, but the scope of the present disclosure is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present disclosure, and all the changes or substitutions should be covered within the scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. An abrasive structure, comprising:

a gasket, the gasket surface comprising a groove and a protrusion;

2. The abrasive structure of claim 1,

the gasket surface comprises a plurality of the grooves; wherein, the distances between the adjacent grooves which are arranged in parallel are equal;

and/or the presence of a gas in the gas,

3. The abrasive structure of claim 1 or 2,

when the gasket surface comprises a plurality of grooves, the widths of at least two grooves are different;

and/or the presence of a gas in the gas,

4. The abrasive structure of claim 3,

the width of the groove comprises at least one of: 0.5 cm; 1.2 cm; 1.4 cm; 1.8 cm;

and/or the presence of a gas in the gas,

the width of the protrusion is at least one of: 0.5 cm; 1.2 cm; 1.4 cm; 1.8 cm.

5. The abrasive structure of claim 3,

the gasket is circular;

6. The abrasive structure of claim 5,

the groove is positioned in a first area of the surface of the gasket;

7. The abrasive structure of claim 5,

when the gasket surface comprises a plurality of grooves, the width of the groove relatively close to the circle center of the circle is larger than the width of the groove relatively far away from the circle center of the circle;

and/or the presence of a gas in the gas,

8. The abrasive structure of claim 7,

along a first direction, the width of the plurality of grooves is gradually reduced;

and/or the presence of a gas in the gas,

9. The abrasive structure of claim 1, further comprising:

10. The abrasive structure of claim 9,

when the gasket surface comprises at least two grooves with different widths, the colors of the first marking layers covering the grooves with different widths are different;

and/or the presence of a gas in the gas,