CN202491166U - Grinding head and grinding device capable of enhancing wafer grinding uniformity - Google Patents

Abstract

The utility model discloses a grinding head for improving the uniformity of wafer grinding, which comprises a grinding head body with a limiting ring at the bottom and a cooling device for the limiting ring arranged on the grinding head. The utility model also discloses a grinding device for improving the uniformity of wafer grinding, comprising a grinding head, a grinding platform and a grinding pad, the grinding pad is laid on the grinding platform, and the grinding head is arranged on the grinding pad , the grinding head adopts the above-mentioned grinding head. The grinding head and the grinding device for improving the uniformity of wafer grinding provided by the utility model can control the temperature of the limiting ring during the grinding process of the wafer by adding a limiting ring cooling device, so that the wafer is in the grinding process. The temperature of the peripheral area and the central area tends to be consistent, which in turn makes the grinding rate of each area of the wafer tend to be consistent, thereby effectively improving the uniformity of wafer grinding and significantly improving product yield.

Description

Grinding Head and Grinding Device for Improving Wafer Grinding Uniformity

technical field

The utility model relates to the field of semiconductor manufacturing, in particular to a grinding head and a grinding device for improving the uniformity of wafer grinding. the

Background technique

The CMP process refers to the chemical mechanical polishing (Chemical Mechanical Polishing) process, or the chemical mechanical planarization (Chemical Mechanical Planarization) process. The chemical mechanical polishing process is a complicated process. It contacts the surface of the wafer with the grinding surface of the polishing pad, and then, through the relative movement between the surface of the wafer and the grinding surface and the action of the grinding liquid, the surface of the wafer is flattened. change. the

Chemical mechanical polishing equipment, also known as a grinding device, is usually used to perform the chemical mechanical polishing process. Please refer to FIG. 1 and FIG. 2 , wherein FIG. 1 is a schematic top view of a conventional grinding device, and FIG. 2 is a schematic side view of a conventional grinding device. Existing grinding device comprises: the grinding head 101 that is provided with limit ring 120 below, grinding pad 102, grinding liquid supply pipe 103 and grinding pad cleaning liquid supply pipe 104, and described grinding head 101 is arranged on the top of described grinding pad 102 The grinding liquid outlet of the grinding liquid supply pipe 103 and the cleaning liquid outlet of the grinding pad cleaning liquid supply pipe 104 are respectively arranged above the grinding pad 102, and the grinding liquid supply pipe 103 and The grinding pad cleaning liquid supply pipe 104 is arranged side by side in a laterally movable bracket 105, the grinding liquid supply pipe 103 is used to supply the grinding liquid, and the grinding pad cleaning liquid supply pipe 104 is used to clean the grinding pad 102 . the

When wafer 106 was carried out grinding process, the wafer 106 to be ground was attached on the grinding head 101, and the to-be-grinding face of this wafer 106 was faced down and contacted the grinding pad 102 of relative rotation, and the downward force provided by grinding head 101 will Wafer 106 is tightly pressed onto the grinding pad 102, and the grinding pad 102 is pasted on the grinding platform (not shown), and when the grinding platform rotates under the drive of the motor, the grinding pad 102 rotates with the grinding platform; at the same time, the grinding The liquid is delivered to the polishing pad 102 through the polishing liquid supply pipe 110 and evenly distributed on the polishing pad 102 by centrifugal force. The abrasive liquid used in the grinding process generally contains chemical etchant and abrasive particles. The chemical reaction between the chemical etchant and the surface to be polished generates softer materials that are easily removed, and then these softer materials are removed from the surface by mechanical friction. The surface of the wafer 106 is ground and removed to achieve a global planarization effect. the

But in use, it is found that after the wafer 106 is ground, the thickness of the peripheral area of the wafer 106 is different from the thickness of the central area of the wafer 106, which makes the grinding effect of the wafer 106 uneven, resulting in a decline in product yield. According to research by scientific researchers, one of the reasons is that the temperature of the wafer 106 is not uniform during the grinding process. The peripheral region of the wafer 106 of the pad has a greater temperature rise relative to the central region of the wafer 106 . The chemical reaction rates of the polishing liquid corresponding to different temperatures are different, and then the polishing rates of each region of the wafer 106 are different, resulting in uneven thickness of the wafer 106 after grinding. the

Therefore, how to provide a grinding head and a grinding device that can improve the uniformity of wafer grinding is a technical problem to be solved urgently by those skilled in the art. the

Utility model content

The purpose of the utility model is to provide a grinding head and a grinding device that improve the uniformity of wafer grinding. By controlling the temperature of the limit ring, the temperature of each area of the wafer in the grinding process tends to be consistent, and the wafer grinding is improved. uniformity. the

In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions:

A grinding head for improving wafer grinding uniformity, comprising a grinding head body with a limiting ring underneath, and a limiting ring cooling device arranged on the grinding head. the

Preferably, in the above-mentioned grinding head for improving the uniformity of wafer grinding, the cooling device for the limiting ring includes a cooling liquid supply plate and a cooling liquid collecting plate stacked on the grinding head body in sequence from top to bottom, The cooling liquid supply pipe and the annular cooling channel arranged inside the limiting ring, the liquid outlets of the cooling liquid supply pipe are arranged above the bottom plate of the cooling liquid supply plate at intervals, and the two sides of the annular cooling channel are respectively The connecting pipe communicates with the cooling liquid supply pan and the cooling liquid collecting pan. the

Preferably, in the above-mentioned grinding head for improving the uniformity of wafer grinding, the limiting ring cooling device further includes a cooling liquid discharge pipe and a valve, and the cooling liquid discharge pipe is connected to the side wall of the cooling liquid collecting tray In the lower part, the valve is arranged on the coolant discharge pipe. the

Preferably, in the above-mentioned grinding head for improving the uniformity of wafer grinding, the cross-sectional shape of the annular cooling channel is rectangular, circular or elliptical. the

Preferably, in the above-mentioned grinding head for improving the uniformity of wafer grinding, the cooling liquid supply plate has a first circular accommodation space with an upward opening, and the cooling liquid supply plate includes a first circular bottom plate and is surrounded by The first annular side plate above the first circular bottom plate, the first circular bottom plate and the first annular side plate enclose the first circular accommodation space. the

Preferably, in the above-mentioned grinding head for improving the uniformity of wafer grinding, there is a second circular accommodating space in the cooling liquid collecting plate, and the cooling liquid collecting plate includes a second circular bottom plate and is surrounded by the A second annular side plate above the second circular bottom plate, the second circular bottom plate and the second annular side plate enclose the second circular accommodating space. the

Preferably, in the above-mentioned grinding head for improving the uniformity of wafer grinding, the grinding head for improving the uniformity of wafer grinding also includes a grinding head drive shaft, and the grinding head drive shaft passes through the cooling liquid supply plate in sequence It is fixedly connected with the grinding head body behind the cooling liquid collecting plate. the

The utility model also discloses a grinding device for improving the uniformity of wafer grinding, comprising a grinding head, a grinding platform and a grinding pad, the grinding pad is laid on the grinding platform, and the grinding head is arranged on the grinding pad , the grinding head adopts the above-mentioned grinding head. the

Preferably, in the above-mentioned polishing device for improving wafer polishing uniformity, it also includes a polishing liquid supply pipe and a polishing pad cleaning liquid supply pipe, and the polishing liquid outlet of the polishing liquid supply pipe is connected to the polishing pad cleaning liquid. The cleaning liquid outlets of the supply pipes are respectively arranged above the polishing pads, and the polishing liquid supply pipes and the polishing pad cleaning liquid supply pipes are arranged side by side in a laterally movable bracket. the

The grinding head and the grinding device for improving the uniformity of wafer grinding provided by the utility model can control the temperature of the limiting ring during the grinding process of the wafer by adding a limiting ring cooling device, so that the wafer is in the grinding process. The temperature of the peripheral area and the central area tends to be consistent, which in turn makes the grinding rate of each area of the wafer tend to be consistent, thereby effectively improving the uniformity of wafer grinding and significantly improving product yield. the

Description of drawings

The grinding head and the grinding device of the utility model for improving the uniformity of wafer grinding are given by the following embodiments and accompanying drawings. the

Fig. 1 is the structural top view schematic diagram of existing grinding device;

Fig. 2 is the structural side view schematic diagram of existing grinding device;

Fig. 3 is a schematic structural view of a grinding device for improving the uniformity of wafer grinding according to an embodiment of the present invention;

4 is an enlarged schematic view of a grinding head and a grinding pad for improving wafer grinding uniformity according to an embodiment of the present invention;

Fig. 5 is a top view distribution diagram of the annular cooling channel in an embodiment of the present invention. the

In the figure, 101, 201-grinding head, 102, 202-grinding pad, 103, 203-grinding liquid supply pipe, 104, 204-grinding pad cleaning liquid supply pipe, 105, 205-transverse movable support, 106, 206- Wafer, 207-grinding head drive shaft, 210-grinding head body, 120, 220-limiting ring, 221-annular cooling channel, 230-coolant supply plate, 240-coolant collection plate, 250-coolant supply pipe , 260-coolant discharge pipe, 270-first connecting pipeline, 280-second connecting pipeline. the

Detailed ways

The grinding head and the grinding device for improving wafer grinding uniformity of the present invention will be further described in detail below. the

The utility model will be described in more detail below with reference to the accompanying drawings, wherein a preferred embodiment of the utility model is shown, it should be understood that those skilled in the art can modify the utility model described herein and still realize the beneficial effects of the utility model. Therefore, the following description should be understood as the broad knowledge of those skilled in the art, but not as a limitation of the present utility model. the

Please refer to Fig. 3 and Fig. 4, wherein Fig. 3 shows a schematic structural view of a grinding device for improving the uniformity of wafer grinding according to an embodiment of the present invention, and Fig. 4 shows a schematic diagram of an embodiment of the present utility model for improving wafer polishing. An enlarged schematic view of the grinding head and pad for grinding uniformity. The grinding device for improving the uniformity of wafer grinding provided by this embodiment includes a grinding head 201, a grinding platform (not shown) and a grinding pad 202, and the grinding pad 202 is laid on the grinding platform, and the grinding head 201 Set on the polishing pad 202, the polishing head 201 is a polishing head that improves the uniformity of wafer polishing. the

The grinding head 201 for improving the uniformity of wafer grinding includes a grinding head body 210 with a limiting ring 220 underneath, and a limiting ring cooling device disposed on the grinding head 201 . In this embodiment, by adding a cooling device for the limiting ring, the temperature of the limiting ring 220 can be controlled during the grinding process of the wafer 206, so that the temperature of the peripheral area and the central area of the wafer 206 tends to be consistent during the grinding process, and then The grinding rate of each area of the wafer 206 tends to be consistent, thereby effectively improving the grinding uniformity of the wafer 206 and significantly improving the product yield. the

Preferably, in this embodiment, the cooling device for the limiting ring specifically includes a cooling liquid supply plate 230, a cooling liquid collecting plate 240, a cooling liquid supply plate and Please refer to FIG. 5 for the tube 250 and the annular cooling passage 221 disposed inside the limiting ring 220 . FIG. 5 is a schematic plan view of the distribution of the annular cooling passage in an embodiment of the present invention. The liquid outlets of the cooling liquid supply pipe 250 are arranged at intervals above the bottom of the cooling liquid supply plate 230, that is, the cooling liquid supply pipe 250 does not contact the cooling liquid supply plate 230, and the annular cooling passage 221 Both sides of the two sides communicate with the cooling liquid supply pan 230 and the cooling liquid collecting pan 240 through connecting pipes (ie, the first connecting pipe 270 and the second connecting pipe 280 ), respectively. The limiting ring cooling device also includes a cooling liquid discharge pipe 260 and a valve (not shown), the cooling liquid discharge pipe 260 is connected to the lower part of the side wall of the cooling liquid collecting pan 240, and the valve is arranged on the On the cooling liquid discharge pipe 260 , the cooling liquid in the cooling liquid collecting tray 240 can be discharged by controlling the valve, and the cooling liquid is usually discharged after batches of wafer grinding are completed. the

Wherein, the cross-sectional shape of the annular cooling channel 221 may be rectangular or circular or elliptical or trapezoidal. In this embodiment, the cross-sectional shape of the annular cooling channel 221 corresponds to the cross-sectional shape of the limiting ring, that is, a rectangular cross-sectional form. Adopting the annular cooling channel 221 in the form of a rectangular cross-section can make the cooling of the annular cooling channel 221 to each area of the limiting ring 220 more uniform, improve the temperature uniformity of each part of the peripheral area of the wafer 206, thereby further improving the grinding uniformity of the wafer 206 . the

In this embodiment, the cooling liquid supply plate 230 has a first circular accommodating space (not shown) with an opening upward. Specifically, the cooling liquid supply plate 230 includes a first circular bottom plate and a first annular side plate surrounding the first circular bottom plate, and the liquid outlets of the cooling liquid supply pipe 250 are arranged at intervals. The bottom plate of the cooling liquid supply plate 230 is above the first circular bottom plate, the first circular bottom plate and the first annular side plate enclose the first circular accommodating space. The cooling liquid collecting tray 240 has a second circular containing space (not shown). Specifically, the cooling liquid collection tray 240 includes a second circular bottom plate and a second annular side plate surrounding the second circular bottom plate, the second circular bottom plate and the second annular side plate The second circular accommodating space is enclosed. Since the cooling liquid supply pan 230 and the cooling liquid collecting pan 240 are relatively simple in structure, they are not illustrated in detail. In addition, the structures of the cooling liquid supply plate 230 and the cooling liquid collecting plate 240 are not limited to the above structures, and the above structure of the cooling liquid supply plate 230 and the cooling liquid collecting plate 240 has the advantages of relatively simple structure and manufacturing process. the

Preferably, in this embodiment, the grinding head 201 for improving wafer grinding uniformity further includes a grinding head drive shaft 207, and the grinding head drive shaft 207 passes through the cooling liquid supply plate 230 and the The cooling liquid collecting plate 240 is then fixedly connected with the grinding head body 210 . the

During the grinding process of the wafer 206, the grinding platform drives the grinding pad 202 to rotate, the grinding head drive shaft 207 drives the grinding head body 210, the cooling liquid supply plate 230 and the cooling liquid collecting plate 240 to rotate, and the grinding liquid supply pipe 203 flows to the grinding pad. 202 to supply grinding liquid, since the liquid outlets of the cooling liquid supply pipe 250 are arranged above the cooling liquid supply plate 230 at intervals, the cooling liquid coming out of the cooling liquid supply pipe 250 first flows to the cooling liquid supply plate 230 Then, the cooling liquid flows into the annular cooling channel 221 in the limit ring 220 through the first connecting pipe 270; then, the cooling liquid flows into the cooling liquid collecting pan 240 through the second connecting pipe 280, usually, the cooling liquid The capacity of the collection tray 240 is sufficient to supply a batch of cooling liquid required for wafer grinding. During the process of flowing through the annular cooling channel 221, the cooling liquid takes away the excess heat generated by the friction between the limiting ring 220 and the polishing pad 202, and controls the temperature of the limiting ring 220 within a reasonable range, so that the wafer 206 is in the process of grinding. The temperature of the region and the central region tends to be consistent, thereby making the grinding rate of each region of the wafer 206 tend to be consistent, thereby effectively improving the grinding uniformity of the wafer 206 and finally significantly improving the product yield. the

Obviously, those skilled in the art can make various changes and modifications to the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and equivalent technologies thereof, the utility model is also intended to include these modifications and variations. the

Claims (10)

1. A grinding head for improving wafer grinding uniformity, comprising a grinding head body with a limit ring below, characterized in that, it also includes a limit ring cooling device arranged on the grinding head. 2. The grinding head for improving the uniformity of wafer grinding according to claim 1, wherein the limiting ring cooling device comprises a cooling liquid supply plate stacked sequentially on the grinding head body from top to bottom With the cooling liquid collection plate, the cooling liquid supply pipe, and the annular cooling channel arranged inside the limiting ring, the liquid outlet of the cooling liquid supply pipe is arranged above the bottom plate of the cooling liquid supply plate at intervals, and the Both sides of the annular cooling channel communicate with the cooling liquid supply pan and the cooling liquid collecting pan through connecting pipes respectively. 3. The grinding head for improving the uniformity of wafer grinding according to claim 2, characterized in that, the limiting ring cooling device also includes a coolant discharge pipe and a valve, and the coolant discharge pipe is connected to the cooling The lower part of the side wall of the liquid collecting tray, the valve is arranged on the cooling liquid discharge pipe. 4. The grinding head for improving wafer grinding uniformity according to claim 2, characterized in that, the cross-sectional shape of the annular cooling channel is rectangular, circular or elliptical. 5 . The grinding head for improving the uniformity of wafer grinding according to claim 2 , wherein the cooling liquid supply plate has a first circular accommodating space with an opening upward. 6 . 6. The grinding head for improving wafer grinding uniformity according to claim 5, wherein the cooling liquid supply plate comprises a first circular bottom plate and a first circular bottom plate surrounding the first circular bottom plate. The annular side plate, the first circular bottom plate and the first annular side plate enclose the first circular accommodation space. the 7 . The grinding head for improving wafer grinding uniformity according to claim 2 , wherein a second circular accommodation space is provided in the cooling liquid collecting tray. 8 . 8. The grinding head for improving the uniformity of wafer grinding according to claim 7, wherein the cooling liquid collecting tray comprises a second circular bottom plate and a second circular bottom plate surrounding the second circular bottom plate. The annular side plate, the second circular bottom plate and the second annular side plate enclose the second circular accommodation space. 9. The grinding head for improving the uniformity of wafer grinding according to claim 2, further comprising a grinding head drive shaft, the grinding head drive shaft passes through the cooling liquid supply plate and the cooling liquid successively. After collecting the disc, it is fixedly connected with the grinding head body. 10. A grinding device for improving wafer grinding uniformity, comprising a grinding head, a grinding platform and a grinding pad, the grinding pad is laid on the grinding platform, and the grinding head is arranged on the grinding pad, characterized in that , the grinding head adopts the grinding head according to any one of claims 1-9. the

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