CN111805414A

CN111805414A - Grinding equipment

Info

Publication number: CN111805414A
Application number: CN202010733512.4A
Authority: CN
Inventors: 彭名君
Original assignee: Qunfu Electronic Technology Shanghai Co ltd
Current assignee: Qunfu Electronic Technology Shanghai Co ltd
Priority date: 2020-07-27
Filing date: 2020-07-27
Publication date: 2020-10-23

Abstract

The invention provides grinding equipment, which comprises a base, a grinding device and a grinding device, wherein the base is provided with a first surface and a second surface which are opposite, and the first surface is circular and is used for adsorbing the lower surface of a wafer; the first driving mechanism is connected with the second surface and used for driving the base to rotate around a perpendicular line at the center of the first surface; the grinding piece is cylindrical, and the axis of the grinding piece is intersected with and perpendicular to the perpendicular line at the circle center of the first surface; the grinding pad covers the side surface of the grinding piece; and the second driving mechanism is connected with the grinding piece and used for driving the grinding piece to rotate around the axis. Among the grinding device, the grinding piece is cylindricly, the axis with the perpendicular line of first face centre of a circle department is crossing and perpendicular, the grinding pad cover in the side of grinding piece makes the linear velocity that the grinding pad acted on the wafer surface is the same to the roughness on control wafer surface that can be better, and does not need complicated subregion grinding head, reduces the cost and the control degree of difficulty of equipment.

Description

Grinding equipment

Technical Field

The invention relates to the technical field of semiconductors, in particular to grinding equipment.

Background

With the development of large-scale integrated circuits, the feature size of devices is continuously reduced, multilayer wiring technology is developed, and with the increase of the number of wiring layers, the requirement for global planarization demands a chemical mechanical polishing process.

As shown in fig. 1 and 2, a conventional chemical mechanical polishing process apparatus includes a polishing head 11, a wafer polishing pad 12, a polishing fluid delivery pipe 13, and a trimming disk 14, where the polishing head 11 loads a wafer 15, such that the wafer 15 is pressed on the wafer polishing pad 12 with its front surface facing downward, the polishing head presses a pressure on the back surface of the wafer 15, and both the polishing head 11 and the wafer polishing pad 12 rotate, so as to drive the wafer 15 to polish on the wafer polishing pad 12, and the polishing fluid delivery pipe 13 delivers a polishing fluid, and the trimming disk 14 corrects the surface of the wafer polishing pad 12, so as to assist in polishing the surface of the wafer 15.

In the existing chemical instrument grinding process equipment, because the grinding head and the wafer grinding pad both move in a circular mode, the linear speeds of all positions on the surface of a wafer relative to the wafer grinding pad are different, so that the grinding speed of the surface of the wafer is inconsistent, the flatness of the surface of the wafer is not easy to control, and the yield of products is influenced.

In order to relatively well control the flatness of the surface of the wafer, the polishing head is divided into 3 zones, 5 zones, 7 zones and even 8 zones in the prior art, and in order to better control the pressure of the zones, the hardware of the equipment is increased, the consumable materials are also more complicated, so that the investment and use cost of the equipment are increased, and as the zones are finer, the size of each zone is reduced, the influence among the zones is more and more large, so that the control difficulty of the equipment is continuously increased.

Therefore, there is a need for a new grinding apparatus to solve the above problems in the prior art.

Disclosure of Invention

The invention aims to provide grinding equipment which can better control the flatness of the surface of a wafer and reduce the cost and the control difficulty of the equipment.

To achieve the above object, the grinding apparatus of the present invention comprises:

the wafer processing device comprises a base, a first clamping piece and a second clamping piece, wherein the base is provided with a first surface and a second surface which are opposite to each other, and the first surface is circular and is used for adsorbing the lower surface of a wafer;

the first driving mechanism is connected with the second surface and used for driving the base to rotate around a perpendicular line at the center of the first surface;

the grinding piece is cylindrical, and the axis of the grinding piece is intersected with and perpendicular to the perpendicular line at the circle center of the first surface;

the grinding pad covers the side surface of the grinding piece;

the second driving mechanism is connected with the grinding piece and is used for driving the grinding piece to rotate around the axis;

and the first driving mechanism and/or the second driving mechanism are/is also provided with a lifting mechanism, and the lifting mechanism is used for driving the base and the grinding piece to be away from or close to each other.

The invention has the beneficial effects that: the grinding piece is cylindrical, the axis is intersected and perpendicular with the perpendicular line of the circle center of the first surface, and the grinding pad covers the side face of the grinding piece, so that the linear speed of the grinding pad acting on the surface of the wafer is the same, the flatness of the surface of the wafer can be better controlled, a complex partitioned grinding head is not needed, and the cost and the control difficulty of equipment are reduced.

Preferably, the polishing apparatus further comprises a conditioning disk for conditioning the polishing pad.

Further preferably, a plurality of protrusions are arranged on one surface of the dressing disk, the vertexes of the protrusions are attached to the surface of the polishing pad, and the connecting line of the vertexes of at least one protrusion intersects with the vertical plane of the axis of the polishing member.

Preferably, the first surface faces upward, and a grinding fluid retaining member is arranged on the periphery of the base and extends toward the first surface to form a groove surrounding the first surface. The beneficial effects are that: can avoid the grinding fluid from running off immediately and improve the utilization rate of the grinding fluid.

Preferably, the grinding equipment further comprises a vacuum pump, at least one group of vacuum suction holes are formed in the first surface and are connected with the vacuum pump through pipelines, and one group of vacuum suction holes comprise at least one vacuum suction hole. The beneficial effects are that: so as to facilitate the adsorption of the wafer.

Further preferably, the distance from each vacuum suction hole in the group of vacuum suction holes to the center of the first surface is the same, and the angles formed by connecting lines of two adjacent vacuum suction holes in the group of vacuum suction holes and the center of the first surface are the same. The beneficial effects are that: the wafer is convenient to apply uniform force, and the wafer is prevented from warping due to uneven stress.

Further preferably, be equipped with three groups of vacuum on the first face and inhale the hole, three groups of vacuum are inhaled the hole and are inhaled hole and third group vacuum including first group vacuum and inhale the hole, second group vacuum and inhale the hole, first group vacuum is inhaled the hole and is close to in the centre of a circle of first face, third group vacuum is inhaled the hole and is close to in the edge of first face, second group vacuum inhale the hole set up in first group vacuum inhale the hole with third group vacuum inhales the centre in hole, and arrives first group vacuum inhale the hole with the distance in hole is inhaled in third group vacuum is the same. The beneficial effects are that: the number of vacuum suction holes is reduced, uniform force can be applied to the wafer, and warping caused by uneven stress of the wafer is avoided.

Preferably, a connecting line between the circle center of any bottom surface of the grinding piece and the circle center of the first surface is perpendicular to the first surface. The beneficial effects are that: the transitional grinding of the grinding piece to the circle center of the wafer is avoided.

Preferably, the diameter of the first surface is the same as the diameter of the wafer. The beneficial effects are that: the wafer is convenient to adsorb, and the wafer is prevented from shaking.

Further preferably, the length of the grinding member in the axial direction is greater than the radius of the first face. The beneficial effects are that: and ensuring that the surface of the wafer is completely ground after the wafer rotates for one circle.

Further preferably, the diameter of the bottom surface of the grinding member is larger than the diameter of the first surface. The beneficial effects are that: the linear velocity brought by the rotation of the grinding piece is larger, so that the grinding speed can be improved.

Further preferably, the rotational speed of the grinding member is greater than the rotational speed of the base. The beneficial effects are that: the polishing pad can obtain consistent linear velocity on the surface of the wafer.

Further preferably, the maximum rotational speed of the grinding member is 400 rpm and the maximum rotational speed of the base is 40 rpm.

Further preferably, the abrasive article exerts a maximum pressure of 30psi against the base.

Preferably, the grinding equipment further comprises a grinding fluid conveying pipeline arranged along the axial direction of the grinding piece, the length of the grinding fluid conveying pipeline is greater than or equal to that of the axial direction of the grinding piece, and a plurality of grinding fluid dripping holes are uniformly formed in the grinding fluid conveying pipeline. The beneficial effects are that: and the sufficient grinding fluid is convenient to drop on the grinding pad.

Further preferably, the distance from the abrasive drop at the abrasive drop orifice to the abrasive pad is less than 5 cm. The beneficial effects are that: the grinding fluid is convenient to splash due to the fact that the falling height is too high in the dropping process.

Further preferably, when the grinding member rotates counterclockwise around the axis, the grinding fluid delivery pipeline is arranged at the upper left of the axis. The beneficial effects are that: the polishing pad is convenient for splashing because the relative movement direction of the polishing liquid and the polishing pad is opposite in the dropping process of the polishing liquid.

Further preferably, when the grinding member rotates clockwise around the axis, the grinding fluid delivery pipeline is arranged at the upper right of the axis. The beneficial effects are that: the polishing pad is convenient for splashing because the relative movement direction of the polishing liquid and the polishing pad is opposite in the dropping process of the polishing liquid.

Drawings

FIG. 1 is a schematic diagram of a prior art chemical mechanical polishing apparatus;

FIG. 2 is a top view of a prior art chemical mechanical polishing process apparatus;

FIG. 3 is a schematic view of the structure of the polishing apparatus of the present invention;

FIG. 4 is a schematic structural diagram of a first driving mechanism according to the present invention;

FIG. 5 is a schematic view of a fixing portion of the present invention;

FIG. 6 is a schematic view of the arrangement of vacuum suction holes in some embodiments of the present invention;

fig. 7 is a top view of the grinding apparatus of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. 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 invention. Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs. As used herein, the word "comprising" and similar words are intended to mean that the element or item listed before the word covers the element or item listed after the word and its equivalents, but does not exclude other elements or items.

To solve the problems of the prior art, an embodiment of the present invention provides a grinding apparatus, referring to fig. 3 and 7, including:

a susceptor 21 having a first surface 211 and a second surface 212 opposite to each other, the first surface being circular and configured to adsorb a lower surface of a wafer;

the first driving mechanism 22 is connected with the second surface 212 and is used for driving the base 21 to rotate around a perpendicular line at the center of the first surface 211;

the grinding piece 23 is cylindrical, and the axis of the grinding piece is intersected with and perpendicular to the perpendicular line at the center of the first surface circle 211;

a polishing pad 24 covering a side surface of the polishing member 23;

a second driving mechanism 25 connected to the grinding member 23 for driving the grinding member 23 to rotate around the axis;

wherein, the first driving mechanism 22 is further provided with a lifting mechanism (not shown), and the lifting mechanism is used for driving the base 21 and the grinding member 23 to move away from or close to each other.

In some embodiments of the present invention, referring to fig. 3, the first surface faces upward, the periphery of the base 21 is provided with a slurry retaining member 213, and the slurry retaining member 213 extends toward the first surface 211 to form a groove surrounding the first surface 211 of the base 21.

In some embodiments of the present invention, the grinding apparatus further includes a vacuum pump, and the first surface is provided with at least one group of vacuum suction holes, and the vacuum suction holes are all connected to the vacuum pump through a pipeline, wherein the group of vacuum suction holes includes at least one vacuum suction hole. In some embodiments, the vacuum pump is a water pump.

In some embodiments of the present invention, distances from each of the vacuum suction holes in the group of vacuum suction holes to a center of the first surface are the same, and angles formed by connecting lines between two adjacent vacuum suction holes in the group of vacuum suction holes and the center of the first surface are the same.

In some embodiments of the present invention, referring to fig. 6, three sets of vacuum holes are disposed on the first surface 211 of the base 21, the three sets of vacuum holes include a first set of vacuum holes 2111, a second set of vacuum holes 2112, and a third set of vacuum holes 2113, the first set of vacuum holes 2111 is close to the center of the first surface 211 of the base 21, the third set of vacuum holes 2113 is close to the edge of the first surface 211 of the base 21, the second set of vacuum holes 2112 is disposed between the first set of vacuum holes 2111 and the third set of vacuum holes 2113, and the distances to the first set of vacuum holes 2111 and the third set of vacuum holes 2113 are the same.

In still other embodiments of the present invention, the vacuum suction holes are distributed on the first surface, and the vacuum suction holes are uniformly distributed on the first surface, such as a microporous ceramic wafer adsorption platform.

In some embodiments of the present invention, referring to fig. 3 and 4, the grinding apparatus 20 further includes a base 26, the vacuum pump 261 is disposed on the base 26, and the first driving mechanism 22 is disposed between the base 26 and the base 21. Specifically, the first driving mechanism 22 includes a supporting portion 221 and a driving motor 222, the supporting portion 221 includes a fixing portion 2211 and a rotating portion 2212, the lower side of the fixing portion 2211 is fixedly connected to the base 26, the upper side of the fixing portion 2211 is provided with a cylindrical outer shell structure 2213, the rotating portion 2212 is in a hollow cylindrical shape, the upper side of the rotating portion 2212 is fixedly connected to the second surface 212 of the base 21, the lower side of the rotating portion 2212 is provided with an inner shell structure 2214 in a cylindrical shape, the inner shell structure 2214 is embedded in the outer shell structure 2213 to form a bearing structure, that is, the inner shell structure 2214 can rotate in the outer shell structure 2213 without shaking. A motor holder 2215 is disposed at one side of the fixing portion 2211, the driving motor 222 is fixed to an upper side of the motor holder 2215, a motor shaft 2221 of the driving motor 222 is parallel to a longitudinal direction of the rotating portion 2212, and the motor shaft 2221 of the driving motor 222 is connected to the rotating portion 2212 through a belt 2222. More specifically, the rotating portion 2212 is provided with a belt cooperating wheel 2216, the motor shaft 2221 is provided with a belt driving wheel 2217, and the belt 2222 is sleeved on the belt cooperating wheel 2216 and the belt driving wheel 2217.

In some embodiments of the present invention, referring to fig. 4, the rotating portion 2212 is provided with a plurality of conduits (not shown) including a main conduit 22121, branch conduits 22122, a connector 22123 and a flexible tube 22124, the branch conduits are connected to vacuum suction holes (not shown) on the first surface 211 of the base 21 in a one-to-one manner, the branch conduits 22122 are connected to the main conduit 22121, the lower end of the main conduit 22122 extends into the connector 22123 and can rotate in the connector 22123, one side of the connector 22123 is connected to one end of the flexible tube 22124, and the other end of the flexible tube 22124 is connected to the vacuum pump 261. Preferably, the position of the connector 22123 is fixed, and a sealing ring (not labeled in the figure) is arranged between the main conduit 22122 and the connector 22123.

In some embodiments of the present invention, referring to fig. 5, the fixing portion 2211 includes a first fixing portion 22111 and a second fixing portion 22112, the first fixing portion 22111 is provided with a first lifting mechanism fixing plate 22113 at the upper side, the second fixing portion 22112 is provided with a second lifting mechanism fixing plate 22114 at the lower side, the first lifting mechanism fixing plate 22113 is connected to one end of the lifting mechanism 22115, and the second lifting mechanism fixing plate 22114 is connected to the other end of the lifting mechanism 22115. Specifically, the lifting mechanism 22115 is a cylinder.

In some embodiments of the present invention, the grinding apparatus further includes a grinding support, the second driving mechanism is fixed to the grinding support, the grinding member includes a rotating shaft disposed on an axis, and the second driving mechanism is connected to two ends of the rotating shaft for driving the grinding member to rotate.

In some embodiments of the present invention, referring to fig. 3, the polishing apparatus 20 further includes a slurry conveying pipeline 27 disposed along the axial direction of the polishing member, the length of the slurry conveying pipeline 27 is greater than or equal to the axial length of the polishing member 23, and a plurality of slurry dripping holes (not shown) are uniformly formed on the slurry conveying pipeline 27. Specifically, the slurry delivery pipe 27 is fixed to the polishing stand (not shown). Specifically, the slurry delivery pipeline 27 is connected to a slurry supply device (not shown) for providing the slurry, wherein the slurry supply device is a well-known technology in the art and will not be described herein again.

In some embodiments of the invention, the distance that the abrasive drop falls to the abrasive pad at the abrasive drop orifice is less than 5 cm. Preferably, the polishing liquid delivery pipeline is not in contact with the polishing pad.

In some embodiments, the slurry supply line is disposed above and to the left of the axis when the polishing member rotates counterclockwise about the axis.

In some embodiments, the slurry supply line is disposed above and to the right of the axis when the polishing member rotates clockwise about the axis.

In some embodiments of the present invention, referring to fig. 3, the polishing apparatus 20 further comprises a conditioning disk 28 for conditioning the polishing pad 24, and the conditioning disk 28 is disposed on the polishing support (not shown). Specifically, a plurality of protrusions (not shown) are disposed on one surface of the conditioning disk 28, the vertexes of the protrusions are attached to the surface of the polishing pad 24, and a connecting line of the vertexes of at least one of the protrusions intersects with a vertical plane of the axis of the polishing member 23.

In some embodiments of the invention, the apex of the projection forms an arcuate surface.

In still other embodiments of the present invention, the apex of the protrusion forms a line parallel to the axial direction of the polishing element.

In other embodiments of the present invention, the apexes of the protrusions form an arcuate line.

In some embodiments of the invention, the second driving mechanism is provided with a lifting mechanism for driving the base and the grinding member away from or close to each other.

In some preferred embodiments of the present invention, the first driving mechanism and the second driving mechanism are both provided with a lifting mechanism, and the lifting mechanism is used for driving the base and the grinding member to move away from or close to each other.

In some embodiments of the present invention, a connection line between a center of any bottom surface of the polishing member and a center of the first surface is perpendicular to the first surface, so that transitional polishing of the polishing member to the center of the wafer is avoided.

In some embodiments of the present invention, the diameter of the first side is the same size as the diameter of the wafer.

In some preferred embodiments of the present invention, the length of the grinding member in the axial direction is greater than the radius of the first face.

In some preferred embodiments of the invention, the bottom surface of the abrasive article has a diameter greater than the diameter of the first surface.

In some embodiments of the invention, the rotational speed of the abrasive article is greater than the rotational speed of the base. Preferably, the maximum rotational speed of the grinding member is 400 rpm and the maximum rotational speed of the base is 40 rpm.

In some embodiments of the invention, the abrasive article rotates at one of a speed of 200 rpm, 225 rpm, 250 rpm, 275 rpm, 300 rpm, 325 rpm, 350 rpm, 375 rpm, or 400 rpm.

In some embodiments of the invention, the base rotates at one of a speed of 20 rpm, 22.5 rpm, 25 rpm, 27.5 rpm, 30 rpm, 32.5 rpm, 35 rpm, 37.5 rpm, or 40 rpm.

In some embodiments of the invention, the abrasive article exerts a maximum pressure of 30psi against the base.

In some embodiments of the invention, the pressure exerted by the abrasive article against the base is one of 15psi, 17.5psi, 20psi, 22.5psi, 25psi, 27.5psi, or 30 psi.

Although the embodiments of the present invention have been described in detail hereinabove, it is apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it is to be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the following claims. Moreover, the invention as described herein is capable of other embodiments and of being practiced or of being carried out in various ways.

Claims

1. A grinding apparatus, comprising:

the grinding pad covers the side surface of the grinding piece;

2. The polishing apparatus of claim 1, further comprising a conditioning disk for conditioning the polishing pad.

3. The polishing apparatus as claimed in claim 2, wherein a face of the conditioning disk is provided with a plurality of protrusions, the apexes of the protrusions each engage with the surface of the polishing pad, and a line connecting the apexes of at least one of the protrusions intersects a perpendicular plane to the axis of the polishing member.

4. The abrading apparatus of claim 1, wherein the first face faces upward, and wherein the base is provided on a periphery thereof with slurry retaining members extending toward the first face to form a channel around the first face.

5. The grinding apparatus according to claim 1, further comprising a vacuum pump, wherein the first surface is provided with at least one set of vacuum suction holes, the vacuum suction holes are connected with the vacuum pump through pipelines, and the set of vacuum suction holes comprises at least one vacuum suction hole.

6. The grinding apparatus according to claim 5, wherein each of the vacuum suction holes in the group of vacuum suction holes has the same distance to the center of the first surface, and the angles formed by connecting the adjacent two of the vacuum suction holes in the group of vacuum suction holes with the center of the first surface are the same.

7. The grinding apparatus of claim 6, wherein the first surface has three vacuum suction holes, the three vacuum suction holes include a first vacuum suction hole, a second vacuum suction hole, and a third vacuum suction hole, the first vacuum suction hole is close to a center of the first surface, the third vacuum suction hole is close to an edge of the first surface, the second vacuum suction hole is disposed between the first vacuum suction hole and the third vacuum suction hole, and distances between the first vacuum suction hole and the third vacuum suction hole are the same.

8. The abrading apparatus of claim 1, wherein a line connecting the center of any bottom surface of the abrading article to the center of the first surface is perpendicular to the first surface.

9. The polishing apparatus of claim 1, wherein the diameter of the first face is the same size as the diameter of the wafer.

10. The abrading apparatus of claim 9, wherein the length of the abrading article in the direction of the axis is greater than the radius of the first face.

11. The abrading apparatus of claim 9, wherein the bottom surface of the abrading article has a diameter greater than the diameter of the first surface.

12. A mill apparatus according to claim 10 or 11, wherein the rotational speed of the grinding member is greater than the rotational speed of the base.

13. A mill apparatus according to claim 12, characterised in that the maximum rotational speed of the grinding member is 400 rpm and the maximum rotational speed of the base is 40 rpm.

14. The abrading apparatus of claim 10 or 11, wherein the abrasive article applies a maximum pressure of 30psi to the base.

15. The grinding equipment according to claim 1, further comprising a grinding fluid conveying pipeline arranged along the axial direction of the grinding member, wherein the length of the grinding fluid conveying pipeline is greater than or equal to the length of the axial direction of the grinding member, and a plurality of grinding fluid dripping holes are uniformly formed in the grinding fluid conveying pipeline.

16. The abrading apparatus of claim 15, wherein the distance that the abrasive drops land at the abrasive drop aperture to the abrasive pad is less than 5 cm.

17. The abrading apparatus of claim 15, wherein the slurry delivery conduit is disposed above and to the left of the axis when the abrading article is rotated counterclockwise about the axis.

18. The abrading apparatus of claim 15, wherein the slurry delivery conduit is disposed to the upper right of the axis when the abrading article is rotated clockwise about the axis.