JP2002016032A - Wafer cleaning apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wafer cleaning apparatus for cleaning abrasive grain and treatment solution remaining in a cut space effectively, after a work-piece is sliced with a wire saw. SOLUTION: The wafer cleaning apparatus includes a cleaning tank 2, having an upper cover 4 moved in an opened or closed state, a bottom face 7 sloping from one side to the other side, and a discharging opening 9 on a bottom of a groove 8 on the other side, a filter unit 10 provided at the opening of the groove 8, a work-piece stage 11 at almost the enter part of the bottom face for mounting the sliced work-piece in manufacturing, and a nozzle 15, arranged at the lower face of the upper cover, facing the work-piece stage for spraying the cleaning solution into the cut space of the work-piece 50 mounted on the work-piece stage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a wafer cleaning apparatus.

[0002]

2. Description of the Related Art For example, a wafer as a semiconductor chip is manufactured by thinly slicing a cylindrical ingot of silicon with a wire saw. In recent years, in order to improve the yield of wafers, the diameter of a wire saw is reduced and the cutting margin is reduced as much as possible. For example,
The cutting margin is about 0.1m for the wafer thickness of about 0.2mm
m from a single ingot to several hundred pieces (500-6
(00 wafers). Then, after slicing, chips, abrasive grains, oil as a processing liquid, etc. remaining between the cutting margins (slits) are washed to obtain a product.

By the way, when the cutting allowance of the wafer becomes narrow, it becomes difficult to wash away the swarf, abrasive grains, oil and the like that have entered the cutting allowance (slit). In addition, if these do not flow down, adjacent wafers will be in close contact with each other due to abrasive grains or oil, and it will be difficult to separate the wafers one by one. If the particles are solidified in the cutting margin, there is a possibility that the particles may be broken when the wafer is separated.
Therefore, in order to remove abrasive grains, oil, and the like remaining in the slit satisfactorily, it is necessary to continuously flow the cleaning liquid in the slit for a long time.

[0004]

Conventionally, after slicing a wafer work by a wire saw device, cleaning work is performed in the wire saw device. Therefore, unless the cleaning work is completed, the next work is set and sliced. I can't work. In addition, since the cleaning time is long, the operation time other than the slicing operation of the wire saw device is long, and the operation efficiency is low. Further, when performing a cleaning operation for cleaning in a wire saw device, it is necessary to seal the entire device, which causes problems such as an increase in the size of the device, an increase in installation area, and an increase in equipment costs.

[0005] The present invention has been made in view of the above points, and is a wafer cleaning apparatus capable of satisfactorily cleaning abrasive grains, machining liquid, and the like remaining in a cutting margin after slicing a work with a wire saw. The purpose is to provide.

[0006]

In order to achieve the above object, according to the present invention, the upper lid is openable and closable, and the bottom surface forms an inclined surface descending from one side to the other side, and is provided on the other side. A washing tank provided with a discharge port at the bottom of the groove, a filter provided at the opening of the groove, and a work table that is installed substantially at the center of the bottom surface and on which a sliced work is placed, It is arranged on the lower surface of the upper lid facing the work table,
A nozzle for injecting a cleaning liquid onto the work placed on the work table.

The work sliced by the wire saw is taken out of the wire saw device, carried into a wafer cleaning device, and placed on a work table. The cleaning liquid sprayed from the nozzles arranged above the work table of the wafer cleaning apparatus flows into each of the cuts (slits) of the work placed on the work table, and the chips clogged in these cuts. Wash off the abrasive, oil as a working fluid. Thereby, the work can be favorably washed in a short time.

According to the second aspect of the present invention, the nozzle has a plurality of injection holes formed on a lower surface of a plurality of pipes arranged in a width direction along a longitudinal direction of the work table so as to face the work table. The configuration is as follows. A nozzle arranged above the work table jets a cleaning liquid from above a work placed on the work table from a large number of injection holes formed in a plurality of pipes. This makes it possible to effectively pour the cleaning liquid into the work allowance.

According to a third aspect of the present invention, in the wafer cleaning apparatus according to the first aspect, a second nozzle is disposed on both sides of the work table so as to face a lower portion of a work placed on the work table. It is characterized by having. The cleaning liquid sprayed from the second nozzle disposed on the side of the work table flows into each of the cutting areas from below the work placed on the work table, and the cutting chips clogged in these cutting areas. Then, the abrasive particles, oil, and the like are washed out. The cleaning effect is improved by allowing the cleaning liquid to flow into the cutting margins from above and below both sides.

[0010] In the invention according to claim 4, the second nozzle is provided with a large number of nozzles on the side surfaces of pipes juxtaposed on both sides of the work table, facing the lower part of the work placed on the work table. The hole is formed. The nozzles arranged on the side of the work table spray the cleaning liquid from both sides of the lower portion of the work placed on the work table from a number of injection holes formed in the pipe. Thus, the cleaning liquid can be effectively poured into the work allowance, and the cleaning effect is improved in combination with the cleaning liquid flowing from above.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan view showing a state in which the upper lid of the wafer cleaning apparatus according to the present invention is seen through, and FIG.
FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 1, and FIG. 4 is an enlarged view of the mounting table shown in FIG.

As shown in FIGS. 1 to 3, the cleaning tank 2 of the wafer cleaning apparatus 1 has a substantially cubic shape that opens upward, and the rear side of the opening is closed by the upper plate 3 along the left-right direction. A cover 4 is attached to the upper plate 3 by a hinge 5 so as to be freely opened and closed. The upper plate 3 is provided with a stopper 6 for locking and supporting the lid 4 at a predetermined opening position indicated by a two-dot chain line in FIG. The bottom plate 7 is provided to be inclined downward (about 10 °) from the front side to the rear side, and a gutter-like groove 8 is provided on the rear side along the left-right direction. As shown in FIG. 3, the groove 8 is formed to be inclined downward from the left and right toward the center, and a discharge port 9 is provided on the bottom surface of the center. A fine wire mesh 10 as a filter is mounted on the opening of the groove 8. This wire mesh 10
Is for filtering the cleaning liquid (contaminated liquid) so that large dust such as wafer fragments generated during cleaning does not flow out. Thus, when the cleaning liquid is reused, relatively large dust contained in the cleaning liquid (contaminated liquid) after cleaning is removed.

At substantially the center of the bottom plate 7, a work table 11 for mounting a work is horizontally installed. The work table 11 is long in the left-right direction, and has a substantially U-shape in a side view in which front and rear portions 11a and 11b are bent upward (FIG. 4), and a screw hole 11c is formed in the front portion 11a along the longitudinal direction. A bolt 12 for clamping and fixing a work sheet 52 to be described later to the rear portion 11b is screwed forward and backward, and a plurality of holes 11d for dropping a cleaning liquid are provided on the bottom surface. I have.

A first nozzle 15 is provided above the work table 11.
However, the second nozzles 16 are arranged on both front and rear sides.
The first nozzle 15 has a plurality of, for example, three pipes 21 to
Reference numerals 23 are arranged side by side at predetermined intervals in the front-rear direction. Each end is connected to the collecting pipe 24, and the other end is closed. The pipes 21 to 23 and the collecting pipe 24 are
The mounting table 11 is fixed to the lower surface (back surface) of the lid 4 by facing the mounting table 11 by 6 and 27. The pipes 21 to 23 are provided with a large number of small holes (hereinafter, referred to as “injection holes”) 21 a to 23 a (FIG. 2) facing the work 50 placed on the work table 11. The injection holes 21a (about 2 mm) of the pipe 21 are arranged in a plurality of rows, for example, three rows in a staggered manner along the longitudinal direction. The same applies to the injection holes 22a and 23a of the pipes 22 and 23. At a substantially central portion of the upper portion of the collecting pipe 24, a base 25 for penetrating the lid 4 and allowing the cleaning liquid to flow is provided. In addition, on the lower surface of the lid 4 and the lower surface of the upper plate 3, double drain plates 28 and 29 are provided around the nozzle 15 in order to prevent the washing liquid sprayed from the nozzle 15 from scattering. Thereby, it is possible to prevent the cleaning liquid from scattering to the outside from the gap between the opening of the cleaning tank 2 and the lid 4.

The second nozzle 16 has two pipes 31,
32 are arranged in front of and behind the work table 11 along the longitudinal direction (left-right direction) of the work table 11 and obliquely upward, and one end is communicated with the collecting pipe 33 and the other end is closed. Have been. These pipes 31, 32, collecting pipe 33
Are fixed to the bottom plate 7 on both left and right sides of the mounting table 11 by support members 36 and 37. A large number of injection holes 31a and 32a are formed in the pipes 31 and 32 so as to face the lower part of the work 50 placed on the work table 11. These injection holes 31a and 32a (about 2 mm) are arranged in a plurality of rows, for example, three rows in a staggered manner along the longitudinal direction. Collecting pipe 33
At the approximate center of the side portion, there is provided a base 34 for flowing the cleaning liquid through the side plate of the cleaning tank 2. The side plate of the cleaning tank 2 is provided with a discharge hole 4a for discharging a cleaning liquid (contaminated liquid) at a predetermined height position. This discharge hole 4
“a” is provided at a level at which the liquid surface of the cleaning liquid (contaminated liquid) immerses the work 50 when the work 50 is immersed in the cleaning liquid for cleaning.

The bases 35, 34 of the nozzles 15, 16 are
The cleaning liquid is supplied by being connected to a cleaning liquid supply pump (both not shown) through a pipe, and the outlets 9 and 4a are connected to a cleaning liquid recirculation device (neither is shown) through a pipe. The operation will be described below. As shown in FIGS. 1 to 3, a work 50 such as a wafer sliced by a wire saw device is taken out from the wire saw device and placed on the work table 11 of the wafer cleaning device 1. As shown in FIG. 4, the work 50 is mounted and fixed on a slice table 51, and the slice table 51 is mounted and fixed on a work sheet 52. The worksheet 52 has a trapezoidal shape in a side view, and the front surface 52a is an inclined surface that is tapered from the upper surface to the lower surface. This worksheet 52
After being placed on the worktable 11, the tip of the bolt 12 is pressed against the front surface 52a and clamped and fixed to the rear portion 12b.

Next, the cleaning liquid is supplied from the cleaning liquid supply pump to the collecting pipes 24 and 33 through the bases 25 and 34 of the nozzles 15 and 16. The cleaning liquid supplied to the collecting pipe 24 is diverted to pipes 21 to 23, and a large number of nozzles 21a are formed.
23a is directed toward the work 50. Further, the cleaning liquid supplied to the collecting pipe 33 is divided into the pipes 31 and 32, and is jetted toward the workpiece 50 from the many nozzles 31 a and 32 a.

The cleaning liquid sprayed from the nozzles 21a to 23a of the pipes 21 to 23 penetrates into the respective cutting margins (slits) from above the work 50, and the cutting chips and abrasive grains clogged in these cutting margins. Wash off oil (working fluid). Further, the cleaning liquid injected from the nozzles 31a and 32a of the pipes 31 and 32 penetrates into the respective cutting margins from obliquely below the work 50, and chips, abrasive grains, oil, and the like clogged in these cutting margins. Wash off.

Since the cutting margin (slit) of the work 50 is very narrow (about 0.1 mm) as described above, it is jetted from the nozzle 15, that is, the injection holes 21 a to 23 a of the pipes 21 to 23, and the work 50 is cut. The cleaning liquid that has entered the cutting allowance from above is difficult to penetrate to the lower part of the cutting allowance, and it requires time.
Therefore, the nozzle 16, that is, the injection hole 31 of the pipes 31 and 32
a, 32a, by injecting the cleaning liquid obliquely downward from the cutting margin toward the cutting margin, cutting chips, abrasive grains clogged at the lower part of the cutting margin,
Wash off oil etc. Thereby, it becomes possible to satisfactorily wash away the swarf, abrasive grains, oil and the like clogged in the cutting margin of the work 50 in a short time. That is, it is possible to clean the work 50 satisfactorily and in a short time.

The cleaning liquid (contaminated liquid) dropped on the bottom plate 7 after cleaning the work 50 flows along the inclined surface of the bottom plate 7,
It flows into the groove 8 through the wire mesh 10. When the work 50 is washed, the thinly sliced wafer may be damaged. Therefore, the cleaning liquid (contaminated liquid) is filtered by the wire net 10 to remove relatively large dust such as wafer fragments. The cleaning liquid (contaminated liquid) that has been filtered by the wire net 10 and has flowed into the groove 8 is discharged from the discharge port 9 and conveyed to the cleaning liquid recirculation device.

When the work 50 is immersed for cleaning, the discharge port 9 is closed, and the cleaning liquid is sprayed from the nozzles 15 and 16 in the same manner as described above, and the work 50 is clogged in the respective cutting margins. The chips, abrasive grains, oil and the like are washed away, and the washing liquid (contaminated liquid) is discharged from the outlet 4a. Outlet 4
The cleaning liquid (contaminated liquid) discharged from a is conveyed to the cleaning liquid recirculation device.

As described above, the work 50 sliced by the wire saw device is cleaned by the wafer cleaning device 1, whereby the work 50 can be cleaned well in a short time. And, the wire saw device is provided with a work 50.
After slicing, the next work can be set and slicing can be performed immediately, and the work efficiency can be greatly improved.

In the above embodiment, cleaning of a semiconductor wafer as a work has been described. However, the present invention is not limited to this. For example, chips, abrasives, and the like clogged in a cutting margin after slicing quartz or the like. The present invention can also be applied to the case where particles, oil, and the like are washed.

[0024]

As described above, according to the present invention,
The work sliced by the wire saw is carried into the wafer cleaning device, and the cleaning liquid is sprayed from the nozzle and poured into each cutting allowance (slit) of the work. By washing off the oil, it becomes possible to clean the work well in a short time. In addition, since the wire saw can set the next work and perform the slicing operation immediately after the slicing operation of the work is completed, the operation rate can be greatly improved.

According to the second aspect of the present invention, the cleaning liquid is sprayed from above the work placed on the work table from a large number of injection holes formed in a plurality of pipes arranged above the work table. In addition, the cleaning liquid can be effectively poured into the work allowance, and the cleaning effect is improved. Claim 3
According to the invention, by injecting the cleaning liquid from the second nozzle arranged on the side of the work table, the cleaning liquid can be supplied to each cutting margin from the lower part of the work placed on the work table, The cleaning effect is greatly improved by flowing the cleaning liquid from above and below both sides.

According to the fourth aspect of the present invention, the cleaning liquid is sprayed from both sides of the lower portion of the work placed on the work table from a plurality of injection holes formed in a pipe arranged on the side of the work table. Thereby, the cleaning liquid can be effectively poured into the work allowance, and the cleaning effect is improved in combination with the cleaning liquid flowing from above.

[Brief description of the drawings]

FIG. 1 is a plan view showing a state in which an upper lid of a wafer cleaning apparatus according to the present invention is seen through;

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is an enlarged view of the mounting table shown in FIG. 2;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wafer cleaning apparatus 2 Cleaning tank 3 Top plate 4 Lid 6 Stopper 7 Bottom plate 8 Groove 9, 4a Discharge port 10 Wire mesh (filter) 11 Work table 12 Bolt 15, 16 Nozzles 21-23, 31, 32 Pipes 21a-23a , 31a, 32a Small hole (injection hole) 24, 33 Collecting tube 25, 34 Base 50 Workpiece (wafer) 51 Slice table 52 Worksheet

Claims (4)

[Claims] A washing tank having an upper lid that can be opened and closed, a bottom surface forming an inclined surface descending from one side to the other side, and a discharge port provided at a bottom of a groove provided on the other side; A filter provided at the opening of the groove, a work table which is installed substantially at the center of the bottom surface, and on which the sliced work is placed, and which is arranged on the lower surface of the upper lid facing the work table, A wafer cleaning apparatus, comprising: a nozzle for spraying a cleaning liquid onto a work placed on a work table. 2. The nozzle according to claim 1, wherein a plurality of injection holes are formed on lower surfaces of a plurality of pipes arranged in the width direction along the longitudinal direction of the work table so as to face the work table. 2. The wafer cleaning apparatus according to 1. 3. The wafer cleaning apparatus according to claim 1, wherein a second nozzle is provided on both sides of the work table so as to face a lower portion of a work placed on the work table. Wafer cleaning equipment. 4. The second nozzle has a large number of injection holes formed on side surfaces of pipes juxtaposed on both sides of the work table so as to face a lower portion of a work placed on the work table. The wafer cleaning apparatus according to claim 3, comprising: