WO2017092367A1

WO2017092367A1 - Silicon block cleansing device

Info

Publication number: WO2017092367A1
Application number: PCT/CN2016/089969
Authority: WO
Inventors: 刘刚; 秦榕; 曹文海; 高亚丽; 李永红; 李文强; 何银凤; 薛心禄; 王素贤; 吴良; 刘言博; 杨紫琪
Original assignee: 朱伯秦
Priority date: 2015-12-03
Filing date: 2016-07-14
Publication date: 2017-06-08
Also published as: CN205264678U

Abstract

A silicon block cleansing device comprises an outer frame (1). The outer frame (1) comprises a base plate (11) and a side frame (12) extending upwardly from the base plate (11). The base plate (11) and the side frame (12) are joined to form an accommodation chamber. Multiple first through holes (11a) are arranged on the base plate (11), and multiple second through holes (12a) are arranged on the side frame (12). A cleansing fluid is introduced via the first through holes (11a) and the second through holes (12a). The device further comprises multiple inner frames (2) stacked in the accommodation chamber. A bottom portion of the inner frame (2) is a grating structure formed by arranging multiple load-bearing strips (21a). The inner frame (2) is configured to carry a silicon block. By configuring a silicon block cleansing device to have a multi-layer structure, a silicon block and the cleansing device are in a line contact rather than a surface contact as disclosed in existing devices, thereby optimizing a polycrystalline silicon surface cleansing technique, increasing an acid cleansing efficiency for a polycrystalline silicon material and product quality, and solving a problem in which because silicon blocks are stacked, acid cleansing cannot be uniformly performed and thus causes an acid spot and color difference.

Description

Silicon block cleaning device

Technical field

The present invention relates to the field of semiconductor processing equipment, and in particular, to a silicon block cleaning apparatus.

Background technique

As part of the final process of polysilicon production, pickled silicon is critical to the maintenance of product purity and surface impurities. The pickling process is to fill the broken silicon block into the silicon block cleaning device, put it in the pickling equipment for pickling, acidly corrode the surface impurities, remove the surface contamination of the silicon material, and make the metal impurities on the silicon surface reach the electronic grade metal quality. Claim.

At present, the existing silicon block cleaning device is a rectangular basket with a square hole at the bottom and the side, and the silicon blocks are stacked together. During the process of pickling the silicon block, the contact surface between the silicon block and the silicon block and between the silicon block and the cleaning basket The contact surface is not sufficiently pickled, resulting in acid spots and chromatic aberrations on the silicon block, which increases the amount of backwash of the product.

Summary of the invention

The invention provides a silicon block cleaning device, which changes the surface contact between the original silicon block and the cleaning device into a line contact, optimizes the polysilicon surface cleaning process, and improves the pickling efficiency and product quality of the polysilicon material.

The technical solution provided by the present invention is to provide a silicon block cleaning device, which includes an outer frame, the outer frame includes a bottom plate and a frame extending upward from the bottom plate, and the bottom plate and the frame surround the frame a plurality of first through holes are formed in the bottom plate, and a plurality of second through holes are formed in the frame, the first through holes and the second through holes are used for injecting a cleaning liquid; wherein The device further includes a plurality of inner frames stacked on each other in the accommodating cavity, and the bottom of the inner frame is a hollow structure including a plurality of carrier bars, and the inner frame is used for loading silicon blocks.

Further, the inner frame is further provided with at least one baffle, and the baffle divides the inner frame into a plurality of lattices.

Further, the number of the grids is 2 to 5.

Further, the bottom plate is further provided with a plurality of screw connectors protruding from the bottom plate.

Further, the top end of the threaded connector is spherical or hemispherical.

Further, the distance between the top end of the threaded connector and the bottom plate is 4-6 mm.

Further, the threaded connection member and the first through hole are respectively distributed in an array on the bottom plate, and the threaded connection member and the first through hole are arranged in a staggered array.

Further, the plurality of carrier strips are arranged at equal intervals.

Further, the carrier strip has a width of 3 to 5 mm and a thickness of 3 to 5 mm.

Further, the first through hole and the second through hole are circular holes or square holes.

The silicon block cleaning device provided by the invention has a layered arrangement of the original cleaning device, so that the surface contact between the original silicon block and the cleaning device becomes line contact, optimizes the polysilicon surface cleaning process, and improves the pickling efficiency of the polysilicon material and The quality of the product solves the problem of uneven pickling caused by the accumulation of silicon blocks, acid spots and chromatic aberration.

DRAWINGS

The above and other aspects, features and advantages of the embodiments of the present invention will become more apparent from

1 is a schematic structural view of a silicon block cleaning device of the present invention;

2a is a schematic structural view of the inner frame of the silicon block cleaning device;

2b is another schematic structural view of the inner frame of the silicon block cleaning device;

3 is a schematic structural view of a first bottom plate of a silicon block cleaning device;

Figure 4 is a cross-sectional view of the outer block of the silicon block cleaning device.

detailed description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the invention may be embodied in many different forms and the invention should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided to explain the principles of the invention and the application of the invention, and the various embodiments of the invention can be understood.

Referring to FIG. 1 , a silicon block cleaning device provided by the present invention includes an outer frame 1 and an inner frame 2 , and the outer frame includes a bottom plate 11 and a frame 12 . The bottom plate 11 and the frame 12 are formed into a receiving cavity, and a plurality of inner frames 2 are stacked on each other in the receiving cavity.

Specifically, the frame 12 is extended upward from the bottom plate 11. The bottom plate is provided with a plurality of first through holes 11a, and the frame is provided with a plurality of second through holes 12a, the first through holes 11a and The second through hole 12a is used for injecting a cleaning liquid to clean the silicon block carried on the inner frame 2. Here, the cleaning liquid is a mixed solution of nitric acid and hydrofluoric acid. Therefore, in order to prevent the silicon block cleaning device from being corroded during the cleaning process, the material of the silicon block cleaning device must be resistant to corrosion and abrasion. Further, the material of the bottom plate 11 and the frame 12 is a PP material. The shape of the second through hole 11a may be a circular hole or a square hole, which is not limited herein.

With reference to FIG. 2a and FIG. 2b, in order to solve the problem of uneven cleaning caused by the accumulation of silicon blocks, the silicon block cleaning apparatus of the present embodiment includes a plurality of inner frames 2 stacked on each other in the accommodating cavity, the inner frame 2 For the silicon block to be cleaned, the number of the inner frame 2 can be set according to actual needs, and is not limited thereto, and is usually set to 2 to 4. The material of the inner frame 2 is an acid-resistant material, for example, the material of the inner frame 2 is a PE material.

In order to achieve a line contact between the silicon block and the silicon block cleaning device, the bottom portion 21 of the inner frame is a hollow structure including a plurality of carrier strips 21a, and the carrier strip 21a is used to carry silicon to be cleaned. The inner frame 2 may be arranged by the carrier strips 21a at equal intervals in the horizontal direction, or may be arranged by the carrier strips 21a at equal intervals in the vertical direction, or may be respectively carried by the carrier strips 21a. The horizontal direction and the vertical direction are arranged at equal intervals. The carrier strip 21a has a width of 3 to 5 mm and a thickness of 3 to 5 mm. The shape of the carrier strip can be selected according to requirements. In order to reduce the contact area between the carrier strip and the silicon block, the silicon is made. The block cleaning is more thorough. Further, the carrier strip 21a has a cylindrical shape and a diameter of 3 to 5 mm.

In the embodiment, the inner frame 2 further includes a side wall 22 corresponding to the frame 12, and the two ends of the carrier strip 21a and the side wall 22 are respectively adjacent to the bottom plate. 11 is connected at one end. Wherein, the side wall 22 mainly serves as a support. The silicon block to be cleaned is laid on the carrier strip 21a, and then the inner frame 2 carrying the silicon block is sequentially stacked into the receiving cavity surrounded by the bottom plate 11 and the frame 12, so that the upper and lower inner frames are The silicon blocks located on the carrier strip 21a in 2 are not in contact, and the unevenness of cleaning due to the accumulation of the silicon blocks is avoided. Wherein, in order to smoothly inject the cleaning liquid injected from the second through hole 12a, the structure of the inner frame 2 stacked on the upper and lower sides may be different (as shown in FIGS. 2a and 2b), for example, the side wall of the inner frame 2 located on the upper layer. 22 may include only two sides in parallel, and the other two sides are formed as an opening, and the cleaning liquid injected from the second through hole 12a can easily flow in from the opening.

Further, referring to FIG. 2a and FIG. 2b, in order to reduce the contact between the silicon block and the silicon block during the cleaning process, the inner frame 2 is further provided with at least one baffle 23, and the baffle 23 will be the inner frame 2 separated into A plurality of lattices, further, the number of the lattices is 2 to 5. When cleaning, laying silicon in these grids can reduce the contact between the silicon block and the silicon block.

Referring to FIG. 3 and FIG. 4, when the inner frame 2 is close to the bottom plate 11, in order to increase the contact area between the silicon block and the cleaning liquid injected into the first through hole 11a, the bottom plate 11 is further provided with A plurality of threaded connectors 11b projecting from the bottom plate 11, the top ends of the threaded connectors 11b being spherical or hemispherical. The threaded connecting piece 11b and the first through hole 11a are respectively distributed in an array on the bottom plate 11, and the threaded connecting piece 11b and the first through hole 11a are arranged in a staggered array. The distance between the top end of the threaded connecting member 11b and the bottom plate 11 is 4-6 mm. Further, the threaded connecting member 11b is a bolt of M10, and the length of the stud is 20 mm (a part of the rotating into the bottom plate 11 is A portion is raised on the bottom plate 11), wherein the number of the screw connectors 11b corresponds to the number of the first through holes 11a. Since the threaded connection member 11b is also in contact with the silicon block cleaning liquid, the material of the threaded connection member 11b is also an acid-resistant material, such as a PP material or a PE material.

The structure of the silicon block cleaning device and its working principle are explained below by way of specific examples. Referring to FIG. 1 to FIG. 4, the bottom plate 11 of the silicon block cleaning device has a size of 520 mm*325 mm*10 mm, and the dimensions of the frame 12 are 325 mm*80 mm*10 mm and 520 mm*80 mm*10 mm, respectively, and the diameter of the first through hole. The bottom plate 11 is equidistantly disposed with 11 rows of first through holes 11a, and each of the columns is equidistantly provided with 21 first through holes 11a; correspondingly, the bottom plate 11 is equally spaced with 12 rows of threads. The connecting members 11b are provided with 20 threaded connecting members 11b at equal intervals in each row. The threaded connection member 11b is a bolt of M10, the length of the stud is 20 mm, the top end is spherical, and the distance between the top end and the bottom plate is 6 mm. The frame 12 is provided with two rows of second through holes 12a, and the second through holes 12a have a diameter of 5 mm. Here, the silicon block cleaning device includes two inner frames 2, and the bottom of each inner frame 2 is a hollow structure formed by the carrier strips 21a, and each inner frame 2 is provided with three baffles 23, The baffle 23 divides the inner frame into four grids. The diameter of the carrier strip 21a is 3 mm, and the spacing between adjacent carrier strips 21a is 10 mm. First, a silicon block is laid on the bottom of the first inner frame 2. After the laying is completed, it is placed in the receiving cavity of the bottom plate 11 and the frame 12, and then laid on the bottom of the second inner frame 2. After the silicon blocks are laid, they are stacked on the first inner frame 2, so that two silicon blocks are formed, and the two silicon blocks are supported by the side walls 22. After the laying is completed, the silicon block cleaning device is placed in a pool with an acid concentration of 10:1 (nitric acid: hydrofluoric acid) for pickling, the pickling time is 5 minutes, and then the silicon block is subjected to cold soaking and hot soaking and ultrasonication. The treatment, wherein the cold soaking time is 6 hours, the hot soaking and the ultrasonic treatment time is 4 hours, and finally the silicon block is dried, and the drying time is 10 hours. In this way, the entire cleaning process is completed, and then the silicon block after the cleaning is sorted, and the silicon material with no color difference and smooth surface is sorted out as a finished product, and after picking up with color difference and crack, it is returned to pickling again, and finally Sorting The finished product is weighed and packaged to calculate the yield.

By calculating the yield, the yield of the silicon block cleaning device in the present embodiment is 20% higher than the original yield, and it can be seen from the results that the silicon block obtained by the silicon block cleaning device in this embodiment is not obvious. The color difference is generated.

The above description is only a specific embodiment of the present application, and it should be noted that those skilled in the art can also make several improvements and retouchings without departing from the principles of the present application. It should be considered as the scope of protection of this application.

Claims

A silicon block cleaning device includes an outer frame, the outer frame includes a bottom plate and a frame extending upward from the bottom plate, wherein the bottom plate and the frame surround a receiving cavity; the bottom plate is provided with a plurality of first a through hole, the frame is provided with a plurality of second through holes, wherein the first through hole and the second through hole are used for injecting a cleaning liquid; wherein the device further comprises a plurality of stacked on each other An inner frame is disposed in the cavity, and the bottom of the inner frame is a hollow structure including a plurality of carrier bars, and the inner frame is used for loading the silicon block.
The silicon block cleaning apparatus according to claim 1, wherein said inner frame is further provided with at least one baffle that divides said inner frame into a plurality of lattices.
The silicon block cleaning apparatus according to claim 2, wherein the number of the lattices is 2 to 5.
The silicon block cleaning apparatus according to claim 1, wherein said bottom plate is further provided with a plurality of screw connectors projecting from said bottom plate.
The silicon block cleaning apparatus according to claim 4, wherein the tip end of the screw connector is spherical or hemispherical.
The silicon block cleaning apparatus according to claim 5, wherein a distance between a tip end of the screw connector and the bottom plate is 4 to 6 mm.
The silicon block cleaning apparatus according to claim 4, wherein said screw connection member and said first through hole are respectively distributed in an array on said bottom plate, and said screw connection member and said first through hole Arranged in a staggered array.
The silicon block cleaning apparatus according to claim 1, wherein the plurality of carrier strips are arranged at equal intervals.
The silicon block cleaning apparatus according to claim 8, wherein the carrier strip has a width of 3 to 5 mm and a thickness of 3 to 5 mm.
The silicon block cleaning device according to claim 1, wherein the first through hole and the second through hole are circular holes or square holes.
The silicon block cleaning apparatus according to claim 5, wherein said screw connection member and said first through hole are respectively distributed in an array on said bottom plate, and said screw connection member and said first through hole Arranged in a staggered array.
The silicon block cleaning apparatus according to claim 6, wherein said screw connector and said The first through holes are respectively distributed in an array on the bottom plate, and the screw connection member and the first through hole are arranged in a staggered array.