TWI664047B - Slicing and moving apparatus and method for silicon carbide crystal - Google Patents

Abstract

The invention provides a silicon carbide (SiC) crystal slicing moving device and a moving method. The SiC slicing moving device includes a support table, two support frames disposed in parallel, and a top plate. After the SiC ingot is subjected to laser irradiation, a plurality of SiC slices are formed on the SiC ingot. The SiC ingot is placed on a support table, the two support frames fix the SiC ingot, and the top plate is moved to the top of the SiC ingot. The first SiC slice is adsorbed, and the top plate is moved, so that the top plate adsorbs the first SiC slice and leaves the SiC ingot. The first SiC slice is placed on the slice receiving table to complete the separation of the first SiC slice. The support is then moved to separate the remaining SiC slices. The method for separating SiC slices is simple and easy to operate, which improves the separation efficiency of SiC slices to a certain extent.

Description

   Silicon carbide crystal slice moving device and moving method   

The invention relates to the field of semiconductor manufacturing, in particular to a silicon carbide (SiC) crystal slice moving device and a moving method.

Silicon carbide (SiC), as one of the representative materials of the third generation of frequency band semiconductors, has excellent physical and chemical properties, and is similar to single crystals such as first-generation semiconductor silicon (Si) and second-generation semiconductor calcium arsenide (GaAs). Compared with materials, it has many excellent properties such as large forbidden band width, high thermal conductivity, large carrier saturation migration rate, high critical breakdown field strength, and low relative dielectric constant. Based on these excellent characteristics, silicon carbide materials are more ideal materials for preparing high-temperature electronic components and high-frequency high-power components. Especially when applied under extreme conditions and harsh conditions, the characteristics of SiC devices far exceed those of Si and GaAs devices. In the field of optoelectronics, compared with the traditional substrate materials Si and sapphire, the SiC lattice and thermal matching are smaller. The performance of Light-Emitting Diodes (LEDs) made of SiC substrates is much better than that of sapphire substrates.

With the maturity of SiC single crystal growth technology, how to obtain a SiC single wafer with a perfect surface has become one of the key technologies for material applications. In order to manufacture high-performance SiC electronic components, it is required that the wafer has a complete crystal lattice, an extremely smooth, non-damaged, ultra-smooth surface, and no crystal orientation deviation. Because even small defects on the surface will destroy the surface properties of the crystalline material, and even cause changes in the crystal structure, affecting the electrical performance of the device.

In the prior art, obtaining a SiC single wafer generally includes the following steps: first, a SiC ingot is provided, and the SiC ingot is generally cylindrical, for example, a cylinder having a thickness of 20 mm and a cross section of 4 inches; and performing wire saw cutting on the SiC ingot (Wire saw slicing) forming a SiC slice, for example, forming a SiC slice with a thickness of 350um; grinding, polishing, and etching the SiC slice to finally form a 4-inch SiC single wafer.

However, because the hardness of the SiC ingot is relatively high, it takes more time to obtain a piece of SiC slice by wire saw cutting. Now generally, SiC slices are formed by laser irradiation to improve the slice efficiency. However, after the laser irradiation, the SiC slice needs to be separated from the SiC ingot on the laser irradiation surface, so it is necessary to provide a SiC crystal slice moving device and a moving method to separate the SiC slice from the SiC ingot.

An object of the present invention is to provide a silicon carbide (SiC) crystal slice moving device and a moving method, which can simply and quickly separate a SiC slice formed after laser irradiation from a SiC ingot.

One of the technical solutions of the present invention is a SiC crystal slicing mobile device, which includes a support table and two support frames arranged in parallel, the extension direction of the support frame is the first direction; the support frame is connected to the support table, and the support frame can It moves along the support platform in the first direction and is fixed on the support platform; two support frames are oppositely arranged for fixing the SiC ingot; and it also includes a top plate connected to the support platform, and the top plate can support along the first direction. The table moves and can rotate along the support table; the top plate is away from or close to the SiC ingot, and is used to adsorb the SiC slices on the SiC ingot, so that the SiC slices leave the SiC ingot.

Further, the aforementioned SiC crystal slicing mobile device may have additional components or changes. For example, one example is: a semiconductor refrigerator and an electrostatic chuck may be sequentially disposed on the top plate side near the SiC ingot; other examples may be: The support base includes a support base and two support pillars. The two support pillars are arranged on both sides of the support base, and the support bases are used to support the SiC ingot. The extension direction of the support pillars is the first direction. The support pillars are connected, and the support frame is moved along the support pillars in the first direction by a slide bar and fixed on the support pillars; the SiC chip moving device may additionally include a chip receiving table for receiving the SiC chips adsorbed on the top plate.

Secondly, the present invention can provide a SiC crystal slice moving method. Laser irradiation is performed on a SiC ingot to form a plurality of SiC slices including a first SiC slice and a second SiC slice on the SiC ingot. The slicing moving device moves the SiC slicing away from the SiC ingot.

Further, the foregoing SiC crystal slice moving method may have additional steps or changes. For example, one example is: it further includes placing a SiC ingot on a support base, the support frame fixes the SiC ingot, and the support frame is positioned above the first direction. The surface is flush with the lower surface of the first SiC slice; move the top plate to the top of the SiC ingot to adsorb the first SiC slice; move the top plate so that the top plate adsorbs the first SiC slice and leaves the SiC ingot; place the first SiC slice on On the slide receiving table. Another example may be: when moving the top plate to the top of the SiC ingot, opening the electrostatic chuck; after placing the first SiC slice on the slice receiving table, closing the electrostatic chuck. Another example may include: moving the top plate so that the top plate adsorbs the first SiC slice. When leaving the SiC ingot, the semiconductor refrigerator is opened, and the top plate is attracted by the movement of the top plate in the first direction and the rotation along the support table. The first SiC slice leaves the SiC ingot and then turns off the semiconductor refrigerator. A further example may be: the refrigeration temperature including the semiconductor refrigerator is -30 ° C to -10 ° C. Another example may include moving the support frame, and then re-fixing the support frame to the SiC ingot. The upper surface of the support frame in the first direction is flush with the lower surface of the second SiC slice, and then repeated until the SiC ingot is separated. On all SiC slices. Another example may be: the laser irradiation of the SiC ingot is performed again to form a plurality of SiC slices on the SiC ingot, and a SiC slice moving device is used to make all SiC slices leave the SiC ingot.

Compared with the prior art, the SiC crystal slicing mobile device and method provided by the present invention, after laser irradiation of a SiC ingot, a plurality of SiC slices are formed on the SiC ingot, and the SiC ingot is placed on a support table with two supports. The SiC ingot is fixed on the frame, and the upper surface of the support frame in the first direction is flush with the lower surface of the first SiC slice. Move the top plate to the top of the SiC ingot, adsorb the first SiC slice, move the top plate, and make the top plate adsorb. The first SiC slice leaves the SiC ingot, and the first SiC slice is placed on the slice receiving table to complete the separation of the first SiC slice, and then the supporting frame is moved so that the upper surface of the supporting frame in the first direction and the second SiC slice are The lower surface is flush, and then the second SiC slice is separated. The method is simple and easy to operate, and the separation efficiency of the SiC slice is improved to a certain extent.

1‧‧‧The first SiC slice

2‧‧‧Second SiC slice

3‧‧‧ The third SiC slice

4‧‧‧ Fourth SiC slice

10‧‧‧Support

11‧‧‧ support

12‧‧‧ support post

20‧‧‧ support

21‧‧‧ Slider

30‧‧‧SiC Ingot

40‧‧‧ Top plate

41‧‧‧Semiconductor refrigerator

42‧‧‧electrostatic chuck

50‧‧‧ Slice Receiving Station

FIG. 1 is a schematic structural diagram of a SiC slice moving device according to an embodiment of the present invention.

In order to make the content of the present invention more clear and easy to understand, the content of the present invention is further described below with reference to the accompanying drawings of the description. Of course, the present invention is not limited to this specific embodiment, and general substitutions well known to those skilled in the art are also covered by the protection scope of the present invention.

Secondly, the present invention is described in detail using a schematic diagram. In detailing the examples of the present invention, for the convenience of explanation, the schematic diagram is not partially enlarged according to general proportions, and should not be used as a limitation on the present invention.

In the prior art, after laser irradiating a silicon carbide (SiC) ingot, a plurality of laser cutting surfaces are formed on the SiC ingot, a plurality of SiC slices are formed between the laser cutting surfaces, and The SiC slice is separated from the SiC ingot. The SiC mobile device is provided with a fixed seat and a top plate. The fixed seat fixes the SiC ingot. The top plate moves to the top of the SiC ingot and is adhered by an adhesive. The first SiC slice at the top of the SiC ingot is separated from the SiC ingot by the movement of the top disc. The SiC moving device can separate the SiC slice from the SiC ingot, but each time a SiC slice is separated, the adhesive needs to be removed and the SiC slice leaves the top plate in order to separate the SiC slice to a certain extent. Increased SiC chip separation time.

In view of the above problems, the inventor proposed a SiC crystal slice moving device and a moving method for improving the separation efficiency of SiC slices.

The core idea of the present invention is: after laser irradiation is performed on the SiC ingot, a plurality of SiC slices are formed on the SiC ingot, the SiC ingot is placed on a support table, and the SiC ingot is fixed by two support frames, and The upper surface of the support frame in the first direction is flush with the lower surface of the first SiC slice. The top plate is moved to the top of the SiC ingot, the first SiC slice is adsorbed, and the top plate is moved to make the top The first SiC slice is sucked away from the SiC ingot by a disk, the first SiC slice is placed on the slice receiving table, the separation of the first SiC slice is completed, and then the supporting frame is moved so that the supporting frame is at the first The upper surface in one direction is flush with the lower surface of the second SiC slice, and then the second SiC slice is separated. The method is simple and convenient to operate, and the separation efficiency of the SiC slice is improved to a certain extent.

FIG. 1 is a schematic structural diagram of a SiC crystal slicing mobile device according to an embodiment of the present invention. As shown in FIG. 1, the present invention proposes a SiC slicing mobile device including a support table 10 and two support frames 20 arranged in parallel. The extension direction of the support frame 20 is a first direction (for example, the x direction in FIG. 1); the support frame 20 is connected to the support base 10, and the support frame 20 can extend along the first direction along all directions. The supporting platform 10 is moved and fixed on the supporting platform 10; two supporting frames 20 are oppositely arranged for fixing the SiC ingot 30.

The SiC ingot 30 is subjected to laser irradiation. As shown in FIG. 1, the SiC ingot 30 is subjected to four laser irradiations to form four laser irradiation surfaces a, b, c, and d on the SiC ingot 30. The SiC on the laser irradiation surface is decomposed into Si and C after being irradiated by the laser, and is easily separated. Therefore, the four laser irradiation surfaces are used as cutting surfaces to form four SiC slices, for example, the first SiC slice 1 , A second SiC slice 2, a third SiC slice 3, and a fourth SiC slice 4.

The SiC slicing moving device further includes a top plate 40 connected to the support table 10, and the top plate 40 can move along the support table 10 in the first direction and can rotate along the support table 10; The top plate 40 is far away from or close to the SiC ingot 30, and is used to adsorb the SiC slices on the SiC ingot 30, so that the SiC slices leave the SiC ingot 30.

The support base 10 includes a support base 11 and two support columns 12. The two support pillars 12 are disposed on both sides of the support base 11. The support base 11 is used to support the SiC ingot 30. Two The support post 12 is used to connect the support frame 20. It can be understood that the support base 11 and the two support columns 12 can be connected at the bottom. The support base 11 can also move in a first direction.

The direction in which the support poles 12 are located is a first direction, and each of the support frames 20 is connected to one of the support poles 12 through a slide bar 21, and the extension direction of the slide bars 21 is a second direction (as shown in FIG. 1). Y direction), that is, the support frame 20 corresponds to the support column 12 one by one, two of the support frames 20 are oppositely disposed, two of the support columns 12 are oppositely disposed, and each of the support frames 20 and The adjacent supporting pillars 12 are connected by a sliding rod 21. The support frame 20 is moved along the support column 12 in the first direction by the slide bar 21 and fixed on the support column 12.

A semiconductor refrigerator 41 (Peltier device) and an electrostatic chuck 42 (Electrostatic chuck) are sequentially disposed on a side of the top plate 40 near the SiC ingot 30. The electrostatic chuck 42 is used to provide static electricity, so that The top plate 40 is capable of adsorbing the SiC slices on the top of the SiC ingot 30, and the semiconductor refrigerator 41 is used to reduce the temperature, so that the top plate 40 is moved along the first direction and rotated along the support table 10 The adsorbed SiC slice leaves the SiC ingot 30.

As can be seen from FIG. 1, the two support pillars 12 are symmetrically arranged on both sides of the support base 11, and the height of the support pillars 12 on either side (for example, the right side) is higher than that on the other side. The height of the supporting column 12. The top plate 40 is located at the top of the support column 12 which is relatively high. The top plate 40 can move along the support column 12 in the first direction, and the top plate 40 can also surround the support. The column 12 is rotated.

The SiC chip moving device further includes a chip receiving station 50 for receiving the SiC chips adsorbed on the top plate 40.

Correspondingly, the present invention also provides a SiC crystal slice moving method, which uses the above-mentioned SiC crystal slice moving device to move. First, laser irradiation is performed on the SiC ingot to form a plurality of SiC slices on the SiC ingot, and then the above-mentioned SiC slice moving device is used to cause the plurality of SiC slices to leave the SiC ingot.

First, the SiC ingot is placed on the support base, the support frame fixes the SiC ingot, and an upper surface of the support frame in a first direction is flush with a lower surface of the first SiC slice; Move the top plate to the top of the SiC ingot to adsorb the first SiC slice; then move the top plate to cause the top plate to adsorb the first SiC slice and leave the SiC ingot; and finally move the first SiC ingot A SiC slice is placed on the slice receiving table to complete the cutting of the first SiC slice. After that, the above steps are repeated repeatedly until all the SiC slices leave the SiC ingot.

Please refer to FIG. 1 to describe the SiC crystal slice moving method provided by the present invention in detail. First, a SiC ingot 30 is provided, and the SiC ingot 30 is subjected to multiple laser irradiations to form a plurality of lasers on the SiC ingot 30. For example, in this embodiment, four laser irradiations are performed on the SiC ingot 30, and four laser irradiation surfaces are formed on the SiC ingot 30, which are laser irradiation surfaces a, b, and c and d, the four laser irradiation surfaces a, b, c and d can be used as cutting surfaces to form four SiC slices. Since the SiC on the irradiated surface is decomposed into Si and C by laser irradiation, the SiC slice can be easily separated from the SiC ingot 30. The four SiC slices are a first SiC slice 1, a second SiC slice 2, a third SiC slice 3, and a fourth SiC slice 4.

Then, the four SiC slices are separated from the SiC ingot 30 using the SiC slice moving device described above. Specifically, the SiC ingot 30 is placed on the support base 11, the support base 11 and the support frame 20 are moved, the support frame 20 is fixed to both sides of the SiC ingot, and the support frame The upper surface of 20 in the first direction is flush with the lower surface of the first SiC slice.

Move the top plate to the top of the SiC ingot, and open the electrostatic chuck 42 to make the top plate 40 adsorb the first SiC slice 1. Open the semiconductor refrigerator 41, and move the top plate 40 in the first direction and rotate along the support column 11 to make the top plate 40 adsorb the first plate under the action of the pulling force and the rotating force. A SiC slice 1 leaves the SiC ingot 30 and then turns off the semiconductor refrigerator 41. The refrigeration temperature of the semiconductor refrigerator is -30 ° C to -10 ° C. Preferably, the refrigeration temperature of the semiconductor refrigerator is -20 ° C.

Move the top plate 40 and the slice receiving table 50 so that the top plate 40 is in contact with the slice receiving table 50. The first SiC slice 1 absorbed by the top plate 40 is placed on the slice receiving table 50 and then closed. The electrostatic chuck 42 and the top plate 40 release the first SiC slice 1, and the separation of the first SiC slice 1 is completed, and then the first SiC slice 1 is subjected to subsequent process steps.

The SiC crystal slice moving method further includes: moving the support frame 12 in a first direction, and then re-fixing the support frame 12 to the SiC ingot 30. The support frame 12 in the first direction The upper surface is flush with the lower surface of the second SiC slice 2, and then the above steps are repeated, leaving the second SiC slice 2 away from the SiC ingot 30, and then repeatedly until all SiC slices on the SiC ingot 30 are separated.

The SiC crystal slice moving method further includes: performing laser irradiation on the SiC ingot 30 again, forming a plurality of SiC slices on the SiC ingot 30, and using the SiC slice moving device to move all SiC slices away from the The SiC ingot is then repeated repeatedly, so that the SiC ingot 30 is completely separated into a plurality of SiC slices.

By adopting the SiC crystal slice moving device and moving method according to the present invention, laser irradiation is performed on a SiC ingot to form a plurality of SiC slices, and then the SiC ingot is placed on the SiC crystal slice moving device, and SiC is fixed by a support frame. The ingot, the first SiC slice on the top of the SiC ingot is adsorbed by the top plate, the SiC slice is separated from the SiC ingot by the movement of the top plate, and then repeated until the SiC ingot is separated into a plurality of SiC slices. By adopting the device and method of the present invention, the operation is simple and convenient, and the SiC slice can be easily separated from the SiC ingot. Compared with the prior art, the time for SiC slice separation is saved, and the efficiency of SiC slice separation is improved.

In summary, according to the SiC crystal slice moving device and method provided by the present invention, after the SiC ingot is irradiated with laser light, a plurality of SiC slices are formed on the SiC ingot, and the SiC ingot is placed on a support table. Two support frames fix the SiC ingot, and the upper surface of the support frame in the first direction is flush with the lower surface of the first SiC slice, and the top plate is moved to the top of the SiC ingot to adsorb the first SiC slice. , Moving the top plate, so that the top plate adsorbs the first SiC slice and leaves the SiC ingot, places the first SiC slice on the slice receiving table, completes separation of the first SiC slice, and then Move the supporting frame so that the upper surface of the supporting frame in the first direction is flush with the lower surface of the second SiC slice, and then the second SiC slice is separated. The method is simple, the operation is convenient, and the degree is improved to a certain extent Separation efficiency of SiC chips.

The above description is only a description of the preferred embodiments of the present invention, and does not limit the scope of the present invention. Any changes and modifications made by those skilled in the art according to the above disclosure shall fall within the protection scope of the claims.

Claims (11)

A silicon carbide (SiC) slicing mobile device includes a support table including a support base and two support columns, the support columns are arranged on both sides of the support base, and the support base is used to support a SiC ingot; parallel Two support frames are provided, an extension direction of the support frames is a first direction; and a top plate is connected to the support platform; wherein the support frames are connected to the support platform, and the support frames can be Moves along the support platform in the first direction and is fixed on the support platform, the support frames corresponding to the support columns are used for fixing the SiC ingot, and the top plate can be supported along the support in the first direction The table moves and can rotate along the support table, and the top plate is far away from or close to the SiC ingot, and is used to adsorb a SiC slice on the SiC ingot, so that the SiC slice leaves the SiC ingot. The SiC slicing mobile device according to item 1 of the scope of patent application, wherein a semiconductor refrigerator and an electrostatic chuck are sequentially disposed on a side of the top plate near the SiC ingot. The SiC slicing mobile device according to item 1 of the scope of patent application, wherein the extending directions of the supporting pillars are the first direction, and each of the supporting frames is connected to one of the supporting pillars through a slide bar. The support frames are moved along the support pillars in the first direction by the slide bar and fixed on the support pillars. The SiC slicing moving device according to item 1 of the patent application scope, wherein the SiC slicing moving device further includes: a slice receiving station for receiving the SiC slice adsorbed on the top plate. A method for moving a silicon carbide (SiC) crystal slice includes the following steps: laser irradiating a SiC ingot, forming a plurality of SiC slices including a first SiC slice and a second SiC slice on the SiC ingot, and using According to the SiC slice moving device described in any one of claims 1 to 4, the at least one of the SiC slices is separated from the SiC ingot. The method for moving a SiC crystal slice according to item 5 of the patent application scope, further comprising: placing the SiC ingot on the support base, the support frames fixing the SiC ingot, and the support frames in the first direction An upper surface of is flush with the lower surface of the first SiC slice; the top plate is moved to a top of the SiC ingot to adsorb the first SiC slice; the top plate is moved to cause the top plate to adsorb the first SiC slice Exit the SiC ingot; and place the first SiC slice on a wafer receiving table. The method for moving a SiC crystal slice according to item 6 of the patent application scope, further comprising: when moving the top plate to the top of the SiC ingot, opening the electrostatic chuck; placing the first SiC slice in the slice to receive After the stage, close the electrostatic chuck. The method for moving a SiC crystal slice according to item 7 in the scope of the patent application, further comprising: moving the top plate so that the top plate adsorbs the first SiC slice and leaves the SiC ingot, opens the semiconductor refrigerator, and passes the top plate. The movement of the disk in the first direction and the rotation along the support table causes the top disk to adsorb the first SiC slice away from the SiC ingot, and then closes the semiconductor refrigerator. According to the method for moving a SiC crystal slice according to item 8 of the scope of the patent application, a refrigeration temperature of the semiconductor refrigerator is -30 ° C to -10 ° C. The SiC crystal slice moving method according to item 6 of the patent application scope, wherein the SiC crystal slice moving method further comprises: moving the support frames, and then re-fixing the support frames to the SiC ingot, the supports The upper surface supported in the first direction is flush with the lower surface of the second SiC slice, and then iteratively repeats until all the SiC slices on the SiC ingot are separated. The method for moving a SiC crystal slice according to item 10 of the scope of application patent, further comprising: performing laser irradiation on the SiC ingot again, forming a plurality of SiC slices on the SiC ingot, and using the SiC slice moving device to make all The SiC slices leave the SiC ingot.