Silicon crystal wafer front soft damage treatment protection structure

Abstract

The utility model discloses a front soft damage treatment protection structure of a silicon crystal wafer, which comprises a silicon crystal wafer body and a protection blue film, and the protection blue film is flatly adhered to one side of the silicon crystal wafer body. The diameter of the blue film is controlled to ensure that one side of the silicon crystal sheet body can be stably protected by the protection blue film, and the overall diameter of the protection blue film is larger than or equal to the diameter of the silicon crystal sheet body, so that the protection blue film serves as a protection layer to replace the contact process when the side, serving as a polished surface, of the silicon crystal sheet body makes contact with a conveying belt in the machining and transferring process; according to the novel back soft damage process, the front chamfer formed on the outer side of the polished surface cannot be scratched, so that the possibility of forming a stacking fault SF in the epitaxial process of the silicon crystal wafer body is reduced, the processing quality and the processing efficiency of the silicon crystal wafer body are greatly improved, and the SF stacking fault rejection rate of the front chamfer surface area after epitaxy is improved from 5% to 0% through the novel back soft damage process. And the processing cost of the epitaxial single wafer can be greatly reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor manufacturing, in particular to a silicon crystal sheet front side soft damage processing protection structure. Background Art

[0002] Metal ion impurities in silicon wafers will significantly reduce minority carrier lifetime and further affect the performance of silicon devices. Back side soft damage is to mechanically damage the back side of silicon wafers, making silicon wafers have non-intrinsic impurity gettering ability. These damages can be used as traps to get rid of impurities in IC processes, thereby getting rid of impurities on the front side of silicon wafers. Sandblasting is a common back side soft damage process. This process uses granular materials of a certain particle size, such as Al 2 O 3 The mortar mixed with water is used to drive the mortar to sandblast the silicon wafer on the moving conveyor belt by air pressure, so as to form "soft" damage on the back of the silicon wafer. The degree of "soft" damage on the back of the silicon wafer is controlled by changing the air pressure, mortar concentration, conveyor belt speed and spray gun height, so as to make the silicon wafer have the ability to getter impurities without causing other negative effects due to excessive mechanical damage;

[0003] At present, during the BSD backside soft damage processing of semiconductor wafers, the final polished surface (front side) of the wafer is placed on the track with the face downward. During the BSD backside soft damage processing, the chamfered position of the front side has a certain probability of contacting the track and forming a scratch. The scratch position is a mechanical damage, and the epitaxial process will form SF stacking fault aggregation, and the product will be scrapped. The scrap rate of this type is as high as more than 5%.

[0004] The semiconductor wafer production process is unable to protect the silicon crystal wafer body from the BSD back side soft damage processing process, which makes it impossible to improve the scrap rate of silicon crystal wafers during the production process. Therefore, a silicon crystal wafer front side soft damage processing protection structure is needed. Utility Model Content

[0005] The purpose of the utility model is to provide a soft damage processing protection structure for the front side of a silicon crystal wafer, by attaching a protective blue film to one side of the polished surface of the silicon crystal wafer body to ensure that the silicon crystal wafer body as a whole will not contact the conveyor belt during transportation and processing, so as to solve the technical problems mentioned in the background technology.

[0006] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a silicon crystal sheet front soft damage processing protection structure, comprising a silicon crystal sheet body and a protective blue film, wherein: the protective blue film is flatly bonded to one side of the silicon crystal sheet body.

[0007] Preferably, one side of the silicon crystal sheet body is a polished surface, and a front chamfer is provided on a side surface of the polished surface.

[0008] Preferably, one side of the silicon crystal sheet body is a BSD surface, and a back chamfer is provided on a side surface of the BSD surface.

[0009] Preferably, the front chamfer and the back chamfer are connected.

[0010] Preferably, the protective blue film is a bright soft PVC film, one side of the protective blue film is coated with acrylic adhesive, and the protective blue film is adhered to the polished side.

[0011] Preferably, the cutting shape of the protective blue film is the same as that of the silicon crystal piece body, and the diameter of the protective blue film is greater than or equal to the diameter of the silicon crystal piece body.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] 1. By controlling the diameter of the blue film, it is ensured that one side of the silicon crystal sheet body can be stably protected by the protective blue film. Since the overall diameter of the protective blue film is greater than or equal to the diameter of the silicon crystal sheet body, when the side as the polishing surface contacts the conveyor belt during the processing and transportation of the silicon crystal sheet body, the protective blue film acts as a protective layer instead of the contact process, so that the front chamfer opened on the outside of the polishing surface will not be scratched, thereby reducing the possibility of stacking fault SF forming on the silicon crystal sheet body during the epitaxial process, greatly improving the processing quality and efficiency of the silicon crystal sheet body.

[0014] 2. Compared with the traditional BSD process, the new back side soft damage process can improve the SF stacking fault scrap rate in the front chamfered surface area after epitaxy from 5% to 0%, which can greatly reduce the processing cost of epitaxial single wafer. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the structure of the utility model;

[0016] Figure 2 This is a schematic diagram of the overall structure of the silicon crystal sheet body of the utility model.

[0017] In the figure: 1, silicon crystal sheet body; 2, protective blue film; 101, polished surface; 102, front chamfer; 103, BSD surface; 104, back chamfer. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0019] The utility model provides: a silicon crystal sheet front soft damage processing protection structure, such as Figure 1-Figure 2 As shown, it includes a silicon crystal sheet body 1 and a protective blue film 2, wherein: the protective blue film 2 is flatly bonded to one side of the silicon crystal sheet body 1, and will be transported with the conveyor belt during the processing and transportation of the silicon crystal sheet body 1. During the transportation process, the silicon crystal sheet body 1 has a certain probability of being placed on the conveyor belt at a certain angle, so that the front chamfer 4 on the side of the smooth surface contacts with the conveyor belt to form scratches, and a large number of stacking faults SF are formed after epitaxy. The set protective blue film 2 can protect the silicon crystal sheet body 1, thereby reducing the scratches on the front chamfer 4 on the side of the polished surface 101, and can greatly improve the production efficiency and production quality of the silicon crystal sheet body 1.

[0020] Preferably, one side of the silicon crystal wafer body 1 is a polishing surface 101, and a front chamfer 4 is provided on the side of the polishing surface 101. The front chamfer 4 provided on the side of the polishing surface 101 can ensure that collision damage can be reduced during the transportation of the silicon crystal wafer body 1, and can better protect the overall transportation of the silicon crystal wafer body 1. At the same time, the front chamfer 4 provided on the side of the polishing surface 101 is used in conjunction with the back chamfer 104 provided on the side of the BSD surface 103, so that the silicon crystal wafer body 1 as a whole has better force-bearing capacity, which can reduce the overall damage of the device during the transportation and processing of the silicon crystal wafer body 1 and improve the processing quality of the silicon crystal wafer body 1.

[0021] Furthermore, one side of the silicon crystal wafer body 1 is a BSD surface 103, and a back chamfer 104 is provided on the side of the BSD surface 103. The back side of the silicon crystal wafer body 1 is the BSD surface 103 which is used as the overall processing surface of the silicon crystal wafer body 1 for processing. During the transportation process, the BSD surface 103 always remains upward, making the silicon crystal wafer body 1 more convenient during transportation and enabling better processing of the silicon crystal wafer body 1.

[0022] Furthermore, the front chamfer 4 and the back chamfer 104 are connected, and the back chamfer 104 opened on the side of the BSD surface 103 can be connected to the front chamfer 4, so that the side of the silicon crystal sheet body 1 is curved, reducing the force generated on the silicon crystal sheet body 1 when the side of the silicon crystal sheet body 1 is subjected to collision force, thereby improving the overall strength of the silicon crystal sheet body 1.

[0023] It is worth mentioning that the protective blue film 2 is a bright soft PVC film. One side of the protective blue film 2 is coated with acrylic adhesive. The protective blue film 2 is adhered to the polished surface 101. The protective blue film 2 is coated with acrylic adhesive, so that the protective blue film 2 can be more conveniently attached to the polished surface 101. Due to the characteristics of the acrylic adhesive itself, when the protective blue film 2 needs to be torn off later, the adhesive can be prevented from adhering to the polished surface 101. The protective blue film 2 can ensure that the polished surface 101 will not directly contact the conveyor belt during the transportation of the silicon crystal sheet body 1. The silicon crystal sheet body 1 is protected by the protective blue film 2, thereby reducing and avoiding scratches, so as to ensure the production quality and processing efficiency of the silicon crystal sheet body 1.

[0024] Specifically, the cutting shape of the protective blue film 2 is the same as that of the silicon crystal wafer body 1, the diameter of the protective blue film 2 is greater than or equal to the diameter of the silicon crystal wafer body 1, and the protective blue film 2 is directly greater than or equal to the overall diameter of the silicon crystal wafer body 1, so that the protective blue film 2 as a whole can stably protect the silicon crystal wafer body 1, and can better improve the SF stacking fault scrap rate of the silicon crystal wafer body 1 in the front chamfer 4 area on the side of the polishing surface 101 after epitaxial growth from 5% to 0%, thereby ensuring that the overall processing cost of the silicon crystal wafer body 1 is reduced by 5%.

[0025] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A silicon crystal wafer front soft damage treatment protection structure, characterized in that: It comprises a silicon crystal sheet body (1) and a protective blue film (2), wherein: The protective blue film (2) is flatly bonded to one side of the silicon crystal piece body (1); one side of the silicon crystal piece body (1) is a polished surface (101), and a front chamfer (102) is provided on the side of the polished surface (101); one side of the silicon crystal piece body (1) is a BSD surface (103), and a back chamfer (104) is provided on the side of the BSD surface (103); the cutting shape of the protective blue film (2) is the same as that of the silicon crystal piece body (1), and the diameter of the protective blue film (2) is greater than or equal to the diameter of the silicon crystal piece body (1).

2. A silicon crystal wafer front side soft damage treatment protection structure according to claim 1, characterized in that: The front chamfer (102) and the back chamfer (104) are connected and arranged.

3. The silicon crystal wafer front side soft damage treatment protection structure according to claim 1, characterized in that: The protective blue film (2) is a bright soft PVC film, one side of the protective blue film (2) is coated with acrylic adhesive, and the protective blue film (2) is adhered to one side of the polished surface (101).

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