WO2020184768A1

WO2020184768A1 - Wafer lapping apparatus

Info

Publication number: WO2020184768A1
Application number: PCT/KR2019/003418
Authority: WO
Inventors: 김진영
Original assignee: 에스케이실트론 주식회사
Priority date: 2019-03-11
Filing date: 2019-03-25
Publication date: 2020-09-17
Also published as: KR20200108615A

Abstract

The present invention provides a wafer lapping apparatus comprising: a top lap; a plurality of through holes perforated in the top lap; a plurality of supply tubes respectively coupled to the plurality of through holes, to supply slurry or air to under the top lap; and a backflow prevention unit provided in the supply tubes, to prevent the slurry under the top lap from backflowing.

Description

Wafer wrapping device

The present invention relates to a wafer manufacturing apparatus, and more particularly, to a wafer wrapping apparatus for improving the flatness of the wafer.

Single crystal silicon ingots are generally grown and manufactured according to the Czochralski method. In this method, polycrystal is melted in a crucible in a chamber, a single crystal seed crystal is immersed in the molten silicon, and then grown into a single crystal silicon ingot (hereinafter, referred to as an ingot) of a desired diameter while gradually increasing it. That's the way.

The manufacturing process of a single silicon wafer includes a single crystal growing process for making an ingot using the above-described method, a slicing process for obtaining a thin disk-shaped wafer by slicing the ingot, and , Edge grinding process to process the outer periphery of the wafer obtained by the slicing process to prevent cracking and distortion, and improve the flatness of the wafer by removing damage caused by mechanical processing remaining on the wafer. It consists of a lapping process for making the wafer, a polishing process for mirroring the wafer, and a cleaning process for removing abrasives or foreign substances attached to the polished wafer.

Here, lapping is performed as a primary polishing process to improve the flatness of the wafer. The lapping process is performed through a wafer wrapping device, and after a wafer placed in the wafer wrapping device is brought into contact with a polishing surface, a chemical polishing agent, Slurry, is supplied to the wafer to perform mechanical friction.

More specifically, the wafer wrapping apparatus includes a platen made of an upper platen and a lower platen. A wafer carrier is disposed between the upper platen and the lower platen, and a plurality of wafers are mounted on the wafer carrier. The wafer carrier is meshed with a sun gear disposed on a rotation axis, which is a central region of the upper and lower base, and an internal gear formed in the inner direction of the circumference.

A plurality of through holes are formed through the upper plate in a vertical direction, and the plurality of through holes may be combined with a plurality of supply pipes. Here, the supply pipe may be composed of a slurry supply pipe or an air supply pipe. Appropriate pressure is provided between the upper platen and the lower platen through an air supply pipe, and a slurry in which abrasive particles, dispersant, and diluent are mixed may be supplied to the wafer under the upper platen through the slurry supply pipe.

However, when the amount of the slurry remaining under the upper plate increases or the pressure inside the platen changes, the slurry remaining inside the platen may flow back into the slurry supply pipe and the air supply pipe. The backwashed slurry causes contamination of the slurry supply pipe and air supply pipe, such as solidification and discoloration, and the contaminated slurry supply pipe and air supply pipe supply the contaminated slurry and air to the platen, causing a problem that adversely affects the wafer wrapping process.

The present invention provides a wafer wrapping apparatus capable of improving the quality of a wafer wrapping process by preventing the slurry remaining inside the platen from flowing back to the supply pipe (slurry supply pipe or air supply pipe).

The present invention is the upper half; A plurality of through holes formed through the upper plate; A plurality of supply pipes respectively coupled to the plurality of through holes to supply slurry or air under the upper plate; And a backflow prevention part provided in the supply pipe to prevent the slurry under the upper plate from flowing backward. It provides a wafer wrapping apparatus comprising a.

The upper plate may further include a fitting tube protruding above the plurality of through holes to allow the plurality of supply tubes to be fitted.

The plurality of supply pipes may include a slurry supply pipe and an air supply pipe.

An upper stopper having a through hole and coupled to the inside of the supply pipe; A lower stopper coupled to an upper portion of the fitting pipe to form a discharge hole; And a float installed movably between the upper stopper and the lower stopper.

The float may have a cylindrical shape.

A plurality of flow path grooves may be formed on the outer peripheral surface of the float.

The flow path groove may be vertically depressed in a lengthwise direction of the float.

The plurality of flow path grooves may be arranged so as to have equal intervals on the outer circumferential surface of the float.

The flow path groove may have a rectangular horizontal cross section with one side open.

The float may include polyvinylidene difluoride (PVDF).

A diameter of the float may be larger than a diameter of the through hole and smaller than a diameter of the fitting tube.

The upper portion of the float may have a flat shape such that a part of the float is inserted into the through hole of the upper stopper.

The upper portion of the float may have a hemispherical shape.

The through hole may be located in the central region of the supply pipe.

The lower stopper may have a cross (+) shape.

On the other hand, the present invention is the upper half; A plurality of through holes formed through the upper plate; A plurality of fitting pipes protruding above the plurality of through holes so that the plurality of supply pipes are fitted; A slurry supply pipe coupled to at least one of the plurality of fitting pipes; An air supply pipe coupled to at least one of the plurality of fitting pipes; And a backflow prevention part provided in at least one of the slurry supply pipe and the air supply pipe to prevent the slurry under the upper plate from flowing backward. It provides a wafer wrapping apparatus comprising a.

According to the wafer wrapping apparatus of the present invention, the quality of the wafer wrapping process can be improved by preventing reverse flow, solidification, discoloration, etc. of the slurry remaining inside the platen by installing a backflow prevention part in the supply pipe (slurry supply pipe or air supply pipe).

1 is a partially cut-away perspective view of a wafer wrapping apparatus according to an embodiment.

FIG. 2 is an enlarged side cross-sectional view of area “A” of FIG. 1.

3 is a perspective view according to the first embodiment of the backflow prevention part of FIG. 2.

4 is a side cross-sectional view of FIG. 3.

5 and 6 are operational diagrams of FIG. 4.

7 and 8 are side cross-sectional views of an enlarged area "A" of FIG. 1 according to a comparative example.

9 is a perspective view and a bottom plan view of a backflow prevention part of the second embodiment.

10 is a perspective view and a top plan view of a backflow prevention part of the third embodiment.

Hereinafter, embodiments will be clearly revealed through the accompanying drawings and descriptions of the embodiments. In the description of the embodiment, each layer (film), region, pattern, or structure is "on" or "under" of the substrate, each layer (film), region, pad or patterns. In the case of being described as being formed in, "on" and "under" include both "directly" or "indirectly" formed do. In addition, the standards for the top/top or bottom/bottom of each layer will be described based on the drawings.

In the drawings, the sizes are exaggerated, omitted, or schematically illustrated for convenience and clarity of description. Also, the size of each component does not fully reflect the actual size. Also, the same reference numerals denote the same elements throughout the description of the drawings. Hereinafter, embodiments will be described with reference to the accompanying drawings.

As shown in Fig. 1, the wafer wrapping apparatus 1 of the embodiment includes an upper plate 10, a lower plate 20, a sun gear 30, an internal gear 40, an internal gear, and a wafer carrier. (50, Wafer Carrier), may be configured to include a supply pipe (60).

The upper plate 10 may polish the wafer W while in contact with the upper surface of the wafer W to be polished. The upper plate 10 may rotate around the rotation shaft 15 in which the sun gear 30 is located, and may be in a fixed position without rotating. The upper platen 10 is disposed on the upper side of the lower platen 20, and may be moved up and down so as to approach or move away from the lower platen 20.

The lower platen 20 is disposed under the upper platen 10 and may polish the wafer W while in contact with the lower surface of the wafer W to be polished. The lower platen 20 may be rotatably mounted about the rotation shaft 15. For example, the lower platen 20 can rotate in the opposite direction to the upper platen 10 when the upper platen 10 rotates, and if the upper platen 10 does not rotate, it can rotate in one direction or in a forward/reverse direction. have.

The upper platen 10 and the lower platen 20 may be generally made of graphite cast iron.

In addition, a plurality of slurry grooves having a lattice shape may be formed in the upper plate 10 and the lower plate 20, respectively. When the wafer (W) is polished, the slurry supplied to the supply pipe 60, which will be described later, moves to and fills the slurry groove, and the upper platen 10 and the lower platen 20 use the supplied slurry particles to separate the wafer W. It can be polished efficiently.

The sun gear 30 may be disposed in the center of the lower platen 20 to rotate around the rotation shaft 15. The sun gear 30 may be engaged with the wafer carrier 50 so as to guide the rotational motion of the wafer carrier 50 together with the internal gear 40.

The internal gear 40 is disposed in a shape surrounding the outer circumferential surface of the lower platen 20 and may be disposed under the upper platen 10. The wafer carrier 50 is engaged with the inner circumferential surface of the internal gear 40 to guide the rotational motion of the wafer carrier 50. The internal gear 40 may be configured to be independently rotated together with the sun gear 30. For example, as shown by an arrow in FIG. 1, the internal gear 40 may rotate in the same direction as the lower platen 20, and the sun gear 30 may rotate in the opposite direction.

The wafer carrier 50 can accommodate the wafer W to be polished while being installed in the interior space of the platen. A wafer mounting hole capable of accommodating at least one wafer W may be formed in the wafer carrier 50. In the embodiment, it is illustrated that four wafers W are mounted on one wafer carrier 50, but the number, size, installation position, etc. can be modified.

A gear is formed on the outer circumferential surface of the wafer carrier 50 so that it can rotate between the lower platen 20 and the upper platen 10 during the lapping process while being meshed with the sun gear 30 and the internal gear 40 described above. The wafer W accommodated in the wafer carrier 50 and rotated between the upper platen 10 and the lower platen 20 contacts the lower surface of the upper platen 10 and the upper surface of the lower platen 20 while Polishing can be done simultaneously.

During the lapping process through the above-described configuration, the wafer W is accommodated in the wafer carrier 50 and can be polished while rotating inside the upper plate 10 and the lower plate 20.

Meanwhile, the supply pipe 60 may be coupled to the upper plate 10 to supply slurry or air toward the wafer W to be polished during the lapping process.

FIG. 2 is an enlarged side cross-sectional view of area “A” of FIG. 1.

As shown in FIG. 2, a plurality of through holes 13 are formed in the upper plate 10, and a plurality of supply pipes 60 may be respectively coupled to the plurality of through holes 13.

A plurality of through holes 13 may be evenly disposed in various areas of the upper plate 10, and the upper plate 10 protrudes above the plurality of through holes 13 so that a plurality of supply pipes 60 are inserted. It may further include a fitting pipe (11). The fitting pipe 11 may protrude to surround the through hole 13 from the upper surface of the upper plate 10 by a certain height at which the supply pipe 60 can be fitted. The outer periphery of the fitting pipe 11 may be in close contact with the inside of the supply pipe 60 being inserted.

The plurality of supply pipes 60 may include a slurry supply pipe 61 or an air supply pipe 62.

The slurry supply pipe 61 may receive a slurry from a slurry powder ring (not shown) and supply it under the upper plate 10. That is, the slurry supply pipe 61 is coupled through the fitting pipe 11 of a plurality of through-holes 13 evenly distributed in various areas of the upper plate 10, so that the slurry is placed under the upper plate 10. It can supply evenly.

The air supply pipe 62 may receive air or nitrogen (N2) gas from a compressor (not shown) and supply it under the upper plate 10. That is, the air supply pipe 62 is coupled through the fitting pipe 11 of the plurality of through holes 13 at appropriate positions distributed on the upper table 10, and air under the upper table 10 when necessary. By supplying (hydraulic pressure), the upper plate 10 and the wafer W or the upper plate 10 and the lower plate 20 can be easily separated.

On the other hand, the wafer wrapping apparatus 1 of the embodiment is provided in the above-described supply pipe 60 (at least one of the slurry supply pipe 61 or the air supply pipe 62), and the slurry remaining under the upper plate 10 It may further include a backflow prevention unit (100, 100a, 100b) for preventing the reverse flow.

3 is a perspective view according to the first embodiment of the backflow prevention unit of FIG. 2, FIG. 4 is a side cross-sectional view of FIG. 3, and FIGS. 5 and 6 are operation diagrams of FIG. 4.

3 to 6, the backflow prevention unit 100 of the first embodiment includes an upper stopper 110, a lower stopper 120, and a float 130. Can include.

The upper stopper 110 has a through hole 111 and may be coupled to the inside of the supply pipe 60. The upper stopper 110 serves to limit the upper movement of the float 130 in the supply pipe 60. The float 130 may be in close contact with the upper stopper 110 and the upper and lower portions of the supply pipe 60 may be isolated or sealed.

Here, the through hole 111 may be located in the central region of the supply pipe 60. For example, the upper stopper 110 may have a donut shape in which a hollow through hole 111 is formed. Slurry or air may flow through the through hole 111. Although one through hole 111 is circularly penetrated in the central region, the shape, position, number, etc. may be modified.

The lower stopper 120 may be coupled to the upper part of the fitting pipe 11 to form the discharge hole 121. The lower stopper 120 may limit the lower movement of the float 130 within the supply pipe 60.

For example, the lower stopper 120 may have a cross (+) shape. Here, the lower stopper may form four discharge holes 121. Of course, the lower stopper 120 is not limited to the above-described shape, and may have various shapes such as one (-) letter, a well positive (#) letter, and the like, and the shape and number of the discharge holes 121 may be modified. .

Due to the structure of the lower stopper 120 described above, the float 130 is in close contact with the lower stopper 120, but through the discharge hole 121, from the upper portion of the supply pipe 60 toward the through hole 13, a slurry or Air can move.

The float 130 may be installed to be movable between the upper stopper 110 and the lower stopper 120. The float 130 may flow up and down in the supply pipe 60 according to the flow of the slurry. That is, a flow space 131 having a certain height H may exist inside the supply pipe 60 between the upper stopper 110 and the lower stopper 120.

For example, the float 130 may have a cylindrical shape. That is, the float 130 may have a circular top and a bottom surface. The upper surface of the float 130 may contact the upper stopper 110, and the lower surface of the float 130 may contact the lower stopper 120.

The float 130 may be a lightweight material that can be freely moved by a flow of slurry or air. For example, the float 130 may be made of a plastic resin material such as polyvinylidene difluoride (PVDF).

Meanwhile, the diameter of the float 130 may be larger than the diameter of the through hole 111 of the upper stopper 110 and smaller than the diameter of the fitting tube 11.

Therefore, as shown in Figure 4, when the float 130 is seated on the lower stopper 120 coupled to the fitting pipe 11, the through hole 111, the flow space 131, from the upper portion of the supply pipe 60, The discharge hole 121 and the through hole 13 may communicate with each other.

Therefore, as shown in Figure 5, when the slurry (Slurry) or air (Air) is supplied from the top of the supply pipe 60, the float 130 may flow in the flow space, but the through hole 111, the flow space 131 ), the discharge hole 121, and through the through hole 13, a continuous flow may be continued.

If, as shown in FIG. 6, the amount of slurry remaining under the top plate 10 increases or the pressure inside the platen changes, the slurry remaining inside the platen is transferred to the slurry supply pipe ( 61) and the air supply pipe 62 can flow back.

In this case, the slurry flowing back as shown by the arrow in FIG. 6 may raise the float 130 to be in close contact with the upper stopper 110 inside the supply pipe 60. The diameter of the float 130 is the diameter of the upper stopper 110 is larger than the diameter of the through hole 111, so that the through hole 111 is closed, and a slurry is supplied inside the supply located at the top of the upper stopper 110. Becomes unable to flow.

If there is no backflow prevention part 100 of the first embodiment described above, as shown in FIGS. 7 and 8, the slurry flows back to the top of the supply pipe 60 while the slurry continues to reverse flow, solidify, It can be seen that it can cause discoloration.

In this way, by installing the backflow prevention unit 100 of the first embodiment in the supply pipe 60 (the slurry supply pipe 61 or the air supply pipe 62), the wafer wrapping apparatus of the embodiment is used to reverse flow and solidify the slurry remaining inside the platen. , Discoloration, etc. can be prevented to improve the quality of the wafer wrapping process.

In the present embodiment, in order to avoid redundant descriptions, parts different from the above-described embodiment will be mainly described.

As shown in FIG. 9, the reverse flow prevention part 100a of the second embodiment differs in that a plurality of flow path grooves 140 are formed on the outer circumferential surface of the float 130a.

The flow path groove 140 may be vertically depressed along the length direction of the float 130a.

The flow path groove 140 may have a rectangular horizontal cross section with one side open. For example, the flow path groove 140 may be formed in a square shape with one side open when viewed from the top. The plurality of flow path grooves 140 may be arranged to have equal intervals on the outer circumferential surface of the float 130a.

The plurality of flow path grooves 140 provide a path for fluid (Slurry or Air) to improve the flow of slurry or air flowing inside the supply pipe 60. I can. That is, the plurality of flow path grooves 140 may improve the flow of slurry to the outside of the float 130.

In addition, as shown in the plan view of the square portion in FIG. 9, when the float 130 is in contact with the lower stopper 120, the area of the discharge hole 121 is relatively widened, thereby forming the through hole 13 Through it, it is possible to smoothly flow the slurry or air.

Of course, the position, number, shape, etc. of the flow path groove 140 described above in the backflow prevention unit 100 of the present embodiment may be modified.

As shown in FIG. 10, the backflow prevention part 100b of the second embodiment has a vertical shape so that a part of the upper part 150 of the float 130b is fitted into the through hole 111 of the upper stopper 110. It differs from the above-described embodiments in that. For example, the upper portion 150 of the float 130b may have a hemispherical shape.

The above-described shape of the float 130b improves adhesion to the upper stopper 110 and further seals the gap with the through hole 111, thereby further preventing the slurry from flowing backward.

Of course, the shape of the float 130 described above in the backflow prevention unit 100b of the present embodiment may be modified.

As described above, according to the wafer wrapping apparatus of the present invention, by providing a backflow prevention unit in the supply pipe, it is possible to improve the quality of the wafer wrapping process by preventing backflow, solidification, discoloration, etc. of the slurry remaining inside the platen.

Features, structures, effects, and the like described in the embodiments above are included in at least one embodiment of the present invention, and are not necessarily limited to only one embodiment. Furthermore, the features, structures, effects, etc. illustrated in each embodiment may be combined or modified for other embodiments by a person having ordinary knowledge in the field to which the embodiments belong. Accordingly, contents related to such combinations and modifications should be interpreted as being included in the scope of the present invention.

The present invention can be applied to an apparatus for manufacturing a semiconductor substrate such as a silicon wafer.

Claims

Upper half;

A plurality of through holes formed through the upper plate;

A plurality of supply pipes respectively coupled to the plurality of through holes to supply slurry or air under the upper plate; And

A backflow prevention part provided in the supply pipe to prevent the slurry under the upper plate from flowing backward; Wafer wrapping apparatus comprising a.
The method of claim 1,

The upper plate is a wafer wrapping apparatus further comprising a fitting tube protruding from the top of the plurality of through-holes to fit the plurality of supply pipes.
The method of claim 2,

The plurality of supply pipes wafer wrapping apparatus including a slurry supply pipe and an air supply pipe.
The method of claim 2,

The backflow prevention part

An upper stopper having a through hole and coupled to the inside of the supply pipe;

A lower stopper coupled to an upper portion of the fitting pipe to form a discharge hole; And

Wafer wrapping apparatus comprising a float installed movably between the upper stopper and the lower stopper.
The method of claim 4,

The float is a wafer wrapping apparatus having a cylindrical shape.
The method of claim 4,

A wafer wrapping apparatus in which a plurality of flow path grooves are formed on the outer peripheral surface of the float.
The method of claim 6,

The flow path groove is a wafer wrapping apparatus that is formed vertically depressed along the length direction of the float.
The method of claim 7,

A wafer wrapping apparatus in which the plurality of flow path grooves are disposed so as to have equal intervals on the outer peripheral surface of the float.
The method of claim 8,

The flow path groove is a wafer wrapping apparatus having a horizontal cross section of a square shape with one side open.
The method of claim 5,

The float is a wafer wrapping apparatus containing polyvinylidene difluoride (PVDF).
The method of claim 5,

Wafer wrapping apparatus having a diameter of the float is larger than the diameter of the through hole and smaller than the diameter of the fitting tube.
The method of claim 5,

A wafer wrapping apparatus having an upper portion of the float having a flat shape so that a part of the float is inserted into the through hole of the upper stopper.
The method of claim 12,

Wafer wrapping apparatus having a hemispherical shape on the top of the float.
The method of claim 4,

The through hole is a wafer wrapping apparatus located in the central region of the supply pipe.
The method of claim 4,

The lower stopper is a wafer wrapping apparatus having a cross (+) shape.
Upper half;

A plurality of through holes formed through the upper plate;

A plurality of fitting pipes protruding above the plurality of through holes so that the plurality of supply pipes are fitted;

A slurry supply pipe coupled to at least one of the plurality of fitting pipes;

An air supply pipe coupled to at least one of the plurality of fitting pipes; And

A backflow prevention unit provided in at least one of the slurry supply pipe and the air supply pipe to prevent the slurry under the upper plate from flowing back; Wafer wrapping apparatus comprising a.
The method of claim 16,

The backflow prevention part

An upper stopper having a through hole and coupled to the inside of the supply pipe;

A lower stopper coupled to an upper portion of the fitting pipe to form a discharge hole; And

Wafer wrapping apparatus comprising a float installed movably between the upper stopper and the lower stopper.