CN213999046U

CN213999046U - Low-abrasion homogenizing grinding system for recycled wafers

Info

Publication number: CN213999046U
Application number: CN202022751346.9U
Authority: CN
Inventors: 汪戬
Original assignee: Zhongsheng Xingye Technology Development Co ltd
Current assignee: Zhongsheng Xingye Technology Development Co ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2021-08-20
Anticipated expiration: 2030-11-25

Abstract

The utility model provides a low-abrasion homogenization grinding system for a reclaimed wafer, which is used for carrying out planarization grinding on the reclaimed wafer, and comprises a front section grinding machine and a matte polishing pad, wherein the front section grinding machine is provided with the matte polishing pad, so that the surface of the reclaimed wafer is in rotary contact with the matte polishing pad and the matte polishing is carried out; and the rear-section grinding machine is arranged on one side of the front-section grinding machine and is provided with a bright surface polishing pad, the regenerated wafer after the matte surface polishing is conveyed to the rear-section grinding machine, and is in rotary contact with the bright surface polishing pad again to perform bright surface polishing. Or a grinding machine table is used and is electrically connected with a driving power supply, the grinding machine table is provided with a matte polishing mode and a bright polishing mode, and the matte polishing mode is executed before the bright polishing mode, so that the regenerated wafer is firstly subjected to matte polishing and then is subjected to bright polishing. Thereby greatly reducing the thickness of the wafer polishing wear and removing the scratches.

Description

Low-abrasion homogenizing grinding system for recycled wafers

Technical Field

The utility model belongs to the technical field of chemical mechanical polishing and specifically relates to a can reduce wafer grinding consume thickness by a wide margin and can get rid of the homogenization grinding system of regeneration wafer low wearing and tearing of scratch.

Background

Chemical Mechanical Polishing (Chemical Mechanical Polishing) is the most widely used method for wafer planarization. As the name suggests, the process principle mainly utilizes the mechanical principle of polishing, and combines with the chemical agent for polishing, so as to further flatten the wafer surface and meet the electrical requirements of the end product by further pressing the polishing wheel to the wafer, wherein the wafer surface has a high and low profile caused by the process of growing the wafer, for example, the requirement of back polishing after the front surface is metalized in the semiconductor process. Briefly, the objective of chemical mechanical polishing is to polish the surface of the completed integrated circuit so that the next layer of metal wires has better growth yield.

Conventionally, a chemical mechanical polishing apparatus generally comprises a high-speed rotating base with a polishing pad, a wafer carrier for holding the wafer, a wafer pressing pad from top to bottom, a polishing slurry nozzle on one side for spraying polishing slurry onto the polishing pad, and a rotating, pressing and spraying process for a predetermined thickness of the wafer. Therefore, the efficiency of CMP is affected by various equipment conditions. Any difference in the settings of any of these conditions may result in wafer breakage and thus affect yield performance. Therefore, in order to avoid the damage of the wafer which is partially metallized due to the bad process parameters, the requirement of recycling the used wafer is derived, and the recycled wafer after grinding is used as the test piece.

Furthermore, in order to meet the actual process standard of semiconductor factories, the surface of the wafer with scratches or used wafer must be polished to be bright and the thickness of the wafer must not be too thin for the wafer to be used as a test piece again. However, in the current wafer recycling method, at least 10 to 60 μm of wafer thickness is sacrificed by grinding to remove the scratches. However, the thickness of the recycled wafer does not meet the standard of semiconductor process, and the purpose of testing wafer is not achieved.

In view of the above, the present inventors have diligently studied and, based on the accumulated experience of the industry for many years, have proposed a homogenized polishing system with low abrasion of recycled wafers, so as to effectively improve the shortcomings of the prior art.

SUMMERY OF THE UTILITY MODEL

The objective of the present invention is to provide a homogenized polishing system for recycled wafers, which can greatly reduce the thickness of the wafer polishing wear and remove scratches.

To achieve the above object, the present invention provides a low-abrasion homogenization polishing system for polishing a reclaimed wafer, comprising: a front end grinder having a matte polishing pad for bringing the reclaimed wafer surface into rotational contact with the matte polishing pad and performing matte polishing; and the rear-section grinding machine is arranged on one side of the front-section grinding machine and is provided with a bright surface polishing pad, the regenerated wafer after the matte surface polishing is conveyed to the rear-section grinding machine, and is in rotary contact with the bright surface polishing pad again to perform bright surface polishing.

To achieve the above object, the present invention further discloses a low-abrasion homogenization polishing system for polishing a reclaimed wafer, comprising: a drive power supply; and the grinding machine table is electrically connected with the driving power supply, the grinding machine table is provided with a matte grinding mode and a bright surface polishing mode, and the matte grinding mode is executed before the bright surface polishing mode so that the regenerated wafer firstly carries out matte grinding and then carries out bright surface polishing.

Preferably, the recycled wafer low-wear homogenizing polishing system further comprises: the slurry nozzle is used for providing the grinding fluid to the side of the regenerated wafer to be ground.

Preferably, the surface roughness Ra of the recycled wafer after matte polishing is minimum to 0.1 mu m; the surface roughness Ra of the polished bright surface of the recycled wafer reaches 1.5nm at most.

In summary, in view of the fact that the physical or electrical properties of the end products of the semiconductor process, such as the MOSFET, can be considered in advance to determine the thickness of the predetermined wafer, the test piece of the regenerated wafer having the same thickness as the main wafer of the process wafer can be further manufactured, and the main wafer can be replaced by the test piece feeding machine, thereby avoiding the phenomena of yield being affected or breaking occurring due to the bad parameter setting conditions of the process. Since the recycled wafer is usually used or has defects, at least the surface scratches should be removed and polished, so the utility model discloses a homogenized grinding system with low wear of recycled wafer can effectively reduce the thickness of the wafer grinding loss by a wide margin to remove scratches, and improve the recycling rate of recycled wafer, and can also satisfy the cost reduction consideration of semiconductor component manufacturers.

Drawings

Fig. 1 is a schematic diagram of a homogenizing grinding system according to a first embodiment of the present invention.

Figure 2 is a schematic diagram of a first embodiment of the homogenizing grinding system of the present invention.

FIG. 3 is a schematic diagram of a second embodiment of the homogenizing grinding system according to the present invention.

Figure 4 is a schematic diagram of a second embodiment of the homogenizing grinding system of the present invention.

1 front section grinder

10 matte polishing pad

2 rear section grinding machine

20 bright surface polishing pad

3 slurry nozzle

4 driving power supply

5 grinding machine table

6 slurry nozzle

8 recycled wafer

9 reclaiming the wafer.

Detailed Description

For clear understanding of the present invention, please refer to the following description with accompanying drawings.

Please refer to fig. 1 and 2, which are a schematic structural diagram and an application diagram of a homogenizing polishing system according to a first embodiment of the present invention. The utility model provides a homogenization grinding system of low wearing and tearing of regeneration wafer for carry out the planarization to regeneration wafer 8 and grind, contain anterior segment and grind machine 1 and back end and grind machine 2.

The front end grinder 1 has a matte polishing pad 10 for bringing the surface of the reclaimed wafer 8 into rotary contact with the matte polishing pad 10 and performing matte polishing. The rear grinder 2 is provided at one side of the front grinder 1 and has a bright surface polishing pad 20, transfers the recycled wafer 8 after the matte finish to the rear grinder 2, and performs bright surface polishing while making rotational contact with the bright surface polishing pad 20 again. Accordingly, by the grinding process of first performing the matte grinding and then performing the bright polishing on the front-stage grinder 1 and the rear-stage grinder 2, the defects and scratches on the recycled wafer 8 can be effectively removed at a low wear thickness, and the test piece requirements required by the semiconductor device manufacturer can be met.

Further, the homogenizing polishing system of the present invention may further comprise at least a slurry nozzle 3 disposed at one side of the front-stage polishing machine 1 and the rear-stage polishing machine 2 for supplying a polishing slurry between the recycled wafer 8 and the matte polishing pad 10; and providing a polishing slurry between the recycled wafer 8 and the bright side polishing pad 20. Therefore, the required grinding fluid can be rapidly provided between the recycled wafer 8 and the matte polishing pad 10 and between the recycled wafer 8 and the bright polishing pad 20 in the grinding process, so that the required grinding treatment of the recycled wafer 8 by the front-stage grinding machine 1 and the rear-stage grinding machine 2 is facilitated. In the present embodiment, the homogenizing and grinding system is described as including one slurry nozzle 3, but the slurry nozzle 3 may be disposed at each of the front-stage grinder 1 and the rear-stage grinder 2.

In addition, preferably, the minimum surface roughness Ra of the recycled wafer 8 after polishing reaches 0.1 μm, and the maximum surface roughness Ra of the recycled wafer 8 after bright surface polishing reaches 1.5nm, so as to reliably remove surface scratches and flaws of the recycled wafer 8, and enable the recycled wafer 8 to form a test piece which can meet the semiconductor processing conditions after grinding.

When the polishing pad is used, the recycled wafer 8 is firstly in rotary contact with the matte polishing pad 10 of the front-stage grinding machine 1 to remove scratches and flaws on the surface of the recycled wafer 8, and then the recycled wafer 8 after matte polishing is conveyed to the rear-stage grinding machine 2, so that the recycled wafer 8 is in rotary contact with the bright polishing pad 20 again to complete bright polishing treatment. The regenerated wafer 8 after the matte polishing treatment of the front section grinding machine 1 and the bright polishing treatment of the rear section grinding machine 2 can meet the condition of being used as a semiconductor process test piece under extremely low abrasion. Here, taking the processing application in which the front-stage grinder 1 and the rear-stage grinder 2 are both disposed above the recycled wafer 8 as an example, the front-stage grinder 1 and the rear-stage grinder 2 are pressed down during grinding to bring the matte polishing pad 10 and the bright polishing pad 20 into rotational contact with the recycled wafer 8, respectively, to perform grinding treatment. Of course, the front-stage grinder 1 and the rear-stage grinder 2 may be disposed under the recycled wafer 8, and the recycled wafer 8 may be pressed down toward the front-stage grinder 1 and the rear-stage grinder 2 to be brought into rotational contact with the matte finish pad 10 and the bright finish pad 20, respectively, to perform grinding.

Please refer to fig. 3 and 4, which are a schematic structural diagram and an application diagram of a homogenizing and grinding system according to a second embodiment of the present invention. Under the technical characteristics of the matte finishing and then the bright finishing, the present embodiment discloses a low-abrasion homogenization polishing system for polishing a recycled wafer 9, which comprises a driving power source 4 and a polishing machine 5. The driving power source 4 is used for providing driving power to the grinding machine table 5, the grinding machine table 5 is electrically connected to the driving power source 4, and the grinding machine table 5 has a matte polishing mode and a bright polishing mode, wherein the matte polishing mode is executed before the bright polishing mode, and the regenerated wafer 9 is firstly subjected to matte polishing and then is subjected to bright polishing. In this embodiment, the polishing process of the recycled wafer 9, i.e., the matte polishing and the bright polishing, can be completed by the matte polishing mode and the bright polishing mode of the polishing machine 5. Specifically, the polishing machine 5 may be driven in the matte polishing mode and the bright polishing mode by adjusting various polishing related parameters or types of polishing liquids, for example, so as to perform a polishing process of polishing the recycled wafer 9 in a matte polishing mode and then in a bright polishing mode.

In order to facilitate the output of the slurry to the surface of the recycled wafer 9 to be polished, the homogenizing polishing system of the present invention may further comprise a slurry nozzle 6 disposed on one side of the polishing platform 5 to provide the slurry to the surface of the recycled wafer 9 to be polished, thereby facilitating the polishing process.

Similarly, in this embodiment, the minimum surface roughness Ra of the recycled wafer 9 after polishing may be 0.1 μm, and the maximum surface roughness Ra of the recycled wafer 9 after polishing the bright surface may be 1.5nm, so as to reliably remove the surface scratches and flaws of the recycled wafer 9, and form a test piece that can meet the semiconductor process conditions after polishing the recycled wafer 9.

When the polishing device is used, the grinding machine table 5 is driven in the matte polishing mode to grind the surface of the regenerated wafer 9 in a matte mode, then the grinding machine table 5 is driven in the bright polishing mode to polish the surface of the regenerated wafer polished in the matte mode, and finally the wafer conforming to the test piece can be obtained. In this embodiment, the polishing machine 5 is also disposed above the recycled wafer 9 to perform the polishing process by pressing downward. Of course, the polishing machine 5 may be disposed below the recycled wafer 9, and the recycled wafer 9 may be pressed down toward the polishing machine 5 to polish the recycled wafer 9.

Particularly, the surface of a formal wafer used in a semiconductor manufacturing process needs to be in a bright surface state, and related manufacturing process treatment can be performed, so that after scratches on the formal wafer are removed, the formal wafer can be replaced by a machine for testing after the formal wafer is used as a regenerated wafer test piece applied to the semiconductor manufacturing process, whether parts needing to be adjusted exist when various processing parameters are applied to the formal wafer under the same scale condition is determined, and the phenomena of yield reduction or breakage of the subsequent formal wafer manufacturing process caused by the parameter condition are avoided. Based on the requirement that the regenerated wafer test piece is in a bright surface state after scratch removal, the conventional intuitive processing method for the regenerated wafer test piece is to directly perform a bright surface polishing and grinding process on the regenerated wafer test piece. However, the bright surface polishing process will remove the scratches on the surface of the regenerated wafer and polish the surface of the regenerated wafer to the scratch grooves originally existing on the surface of the wafer, so the depth of the scratch grooves will increase with the bright surface polishing, and the increase rate is quite large. In order to completely remove scratch grooves with the depth increased along with bright surface polishing and grinding and enable the surface of the regenerated wafer test piece to be in a flat bright surface state, the bright surface polishing and grinding treatment needs to be carried out for a plurality of times, so that the thickness of the regenerated wafer test piece at least needs to be sacrificed by 10-60 mu m, and the surface of the regenerated wafer test piece can be in the flat bright surface state. Therefore, in the wafer recycling method of the prior art, the polished wafer cannot meet the requirements of the semiconductor process, and particularly, for a part of the used wafer to be used as a test piece, the wafer has an extremely thin thickness due to the polishing process in the semiconductor process, and in the method of the wafer recycling method of the prior art, the wafer cannot be processed at all to be recycled due to the extremely high polishing sacrificial thickness.

The utility model discloses a homogenization grinding system overcomes the technical bias among this technical field, adopts for the anterior segment to grind and polish the processing for the matte, polishes the matte again after regeneration wafer carries out back end bright face polishing and grinds, and can effectively solve the too much wafer thickness sacrificial problem that the past all used bright face polishing to grind and cause. In the case of matte polishing, the depth of the scratch groove originally present on the wafer surface is increased during the removal of the scratch, but the depth increase is very small, so that the depth of the scratch groove on the surface of the reclaimed wafer becomes very shallow after the matte polishing, and becomes too shallow to be recognized by the naked eye. Carry out bright face polishing and grinding again this moment, can reduce very by a wide margin the required grinding thickness of sacrificing of regeneration wafer when getting rid of the scratch, through the utility model discloses a homogenization grinding system, regeneration wafer only needs the thickness of sacrificing about 2 ~ 3 μm can form and accords with the bright face demand as the test strip. Therefore, the utility model discloses a homogenization grinding system has utilized special design thinking in fact and has overcome technical bias among the technical field to the grinding mechanism of bright face polishing again is polished to the fog face earlier, reduces effectively by a wide margin required sacrificial grinding thickness when scratch is got rid of to regeneration wafer reaches the efficiency of low wearing and tearing, lets all kinds of wafers that have used or have the scratch all accessible the utility model discloses carry out regeneration treatment to keep in line with semiconductor processing procedure service standard after handling. That is, the spirit of the present invention is to polish the surface with a matte finish and polish the surface with a bright finish, so as to solve the problem of the conventional wafer regeneration method, and to provide the overall technical features of being dense and inseparable, and not to be separately and independently inspected.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention; therefore, the present invention should be covered by the claims without departing from the equivalent scope of the present invention by changing, modifying or replacing the components with the same function.

Claims

1. A low-abrasion homogenized polishing system for recycled wafers, which is used for performing planarization polishing on the recycled wafers, comprising:

a front end grinder having a matte polishing pad for bringing the reclaimed wafer surface into rotational contact with the matte polishing pad and performing matte polishing; and

and the rear-section grinding machine is arranged on one side of the front-section grinding machine and is provided with a bright surface polishing pad, the recycled wafer after the matte surface polishing is conveyed to the rear-section grinding machine, and is in rotary contact with the bright surface polishing pad again to perform bright surface polishing.

2. The reclaimed wafer low-wear homogenizing and grinding system of claim 1 further comprising: at least one slurry nozzle disposed at one side of the front-stage grinding machine and the rear-stage grinding machine for providing grinding fluid between the recycled wafer and the matte polishing pad; and providing a grinding fluid between the recycled wafer and the bright surface polishing pad.

3. The system of claim 2, wherein the recycled wafer low-wear homogenization grinding system is characterized in that the surface roughness Ra of the recycled wafer after matte finishing is as small as 0.1 μm.

4. The system of claim 3, wherein the recycled wafer has a surface roughness Ra of up to 1.5nm after bright surface polishing.

5. A low-abrasion homogenized polishing system for recycled wafers, which is used for performing planarization polishing on the recycled wafers, comprising:

a drive power supply;

and the grinding machine table is electrically connected with the driving power supply, the grinding machine table is provided with a matte grinding mode and a bright surface polishing mode, and the matte grinding mode is executed before the bright surface polishing mode so that the regenerated wafer firstly carries out matte grinding and then carries out bright surface polishing.

6. The reclaimed wafer low-wear homogenizing and grinding system of claim 5 further comprising: and the slurry nozzle is arranged on one side of the grinding machine table and is used for providing grinding fluid to the surface of the regenerated wafer to be ground.

7. The system of claim 6, wherein the recycled wafer surface roughness Ra after matte finishing is as small as 0.1 μm.

8. The system of claim 7, wherein the recycled wafer has a surface roughness Ra of up to 1.5nm after bright surface polishing.