Stopping piece suite for furnace tube, furnace tube for wafer film deposition and method

Abstract

The invention provides a separation blade suite for a furnace tube, and the furnace tube and method for wafer film deposition. The furnace tube comprises a wafer boat, a tube body and a separation blade, the wafer boat is arranged in the tube body, the wafer boat is sequentially provided with a first placing area, a second placing area and a third placing area in the axial direction, the first placing area and the third placing area are located at the two ends of the wafer boat respectively, and the second placing area is used for placing a product wafer; the plurality of separation blades are arranged in the first placing area and the third placing area, and the surface area of the separation blade which is placed in the first placing area and / or the third placing area and is close to one side of the second placing area is the same as or similar to the surface area of the product wafer. According to the embodiment provided by the invention, the patterned separation blades are arranged at the two ends of the second placement area, so that the reaction gas occupied by the patterned separation blades is the same as the reaction gas occupied by the wafers, and the consistency and uniformity of the thickness of a film formed by each wafer in the tube body are ensured.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a baffle kit for a furnace tube, a furnace tube for wafer thin film deposition, and a method. Background Art

[0002] Plasma enhance atomic layer deposition (PEALD) technology is a special chemical vapor deposition thin film technology. Specifically, the reaction gas is uniformly introduced into the furnace tube through the exhaust pipe, so that a gas-curing chemical reaction occurs on the surface of the wafer in the furnace tube to form a thin film.

[0003] Among them, a wafer boat is arranged in the furnace tube, and the wafer is placed on the wafer boat. Due to the characteristics of the furnace tube, dummy wafers need to be inserted on the top and bottom of the wafer boat. Since the surface area of ​​the dummy wafer is flat, there is no pattern on it, and the surface area is small, the dummy wafer surface has a small adsorption capacity for the reaction gas, while the product wafer has various patterns on its surface and a larger surface area, and its adsorption capacity for the reaction gas is stronger than the dummy wafer; this will cause the product wafer close to the dummy wafer to be allocated more reaction gas, so that the film thickness formed by the product wafer close to the dummy wafer is relatively high, and the film thickness formed by the product wafer far from the dummy wafer is relatively thin, resulting in relatively poor uniformity of the film formed by the wafers in the entire furnace tube. In addition, the fluctuation of the uniformity of the film will affect the subsequent etching process and the reliability of semiconductor production. Summary of the invention

[0004] The object of the present invention is to provide a baffle kit for a furnace tube, a furnace tube and a method for wafer thin film deposition, so as to improve the uniformity and consistency of the thickness of the thin film formed on the wafer in the furnace tube, so as to ensure the reliability of semiconductor production.

[0005] To achieve the above-mentioned object, in a first aspect, the present invention provides a furnace tube for wafer thin film deposition, comprising a wafer boat, a tube body and a baffle;

[0006] The wafer boat is arranged in the tube body, and the wafer boat is provided with a first placement area, a second placement area and a third placement area in sequence along its axial direction, and the first placement area and the third placement area are respectively located at two ends of the wafer boat, and the second placement area is used to place product wafers;

[0007] Several baffles are arranged in the first placement area and the third placement area, and the baffles placed in the first placement area and / or the third placement area and close to the second placement area have the same or similar surface area as the product wafer.

[0008] In some embodiments, the baffle includes a patterned baffle, which is arranged on the first placement area and / or the third placement area and close to one side of the second placement area, and the surface area of ​​the patterned baffle is the same as or similar to the surface area of ​​the product wafer.

[0009] In some embodiments, patterns are etched on the surfaces of several of the baffles to form patterned baffles with different surface areas, and the surface area of ​​at least one of the patterned baffles is the same as or similar to the surface area on the product wafer.

[0010] In some embodiments, the furnace tube for wafer thin film deposition further includes a control plate disposed on the wafer boat, and the control plate is placed in the second placement area.

[0011] In some embodiments, the product wafer is placed on the first placement area and / or the third placement area and close to the second placement area.

[0012] In some embodiments, the surface areas of the blocking sheets placed in the first placement area and the third placement area are the same as or similar to the surface areas of the product wafer.

[0013] In a second aspect, the present invention provides a baffle set for a furnace tube, comprising a series of baffles with different surface areas, and the baffle of each surface area has at least one baffle.

[0014] In some embodiments, a deposition etching method is used to etch a pattern on the surface of the baffle, so that the surface area of ​​a portion of the baffle is the same as or similar to the surface area of ​​the product wafer.

[0015] In a third aspect, the present invention provides a method for wafer thin film deposition, using the furnace tube and the furnace tube baffle kit, the method comprising:

[0016] placing a plurality of product wafers in the second placement area;

[0017] Placing baffles on the first placement area and the third placement area, and the baffle placed on the first placement area and / or the third placement area and close to the second placement area has a surface area that is the same as or similar to that of the product wafer;

[0018] Reaction gas is introduced into the tube body to form a thin film on the product wafer.

[0019] In some embodiments, the step of placing baffles on the first placement area and the third placement area, wherein the baffles placed on the first placement area and / or the third placement area and close to the second placement area have the same or similar surface area as the product wafer, comprises:

[0020] Selecting the baffle sheet from the baffle sheet kit, the baffle sheet having the same or similar surface area as the product wafer;

[0021] At least one baffle having a surface area that is the same as or similar to that of the product wafer is placed in the first placement area and / or the second placement area and close to a side of the second placement area.

[0022] The beneficial effects of a baffle kit for a furnace tube, a furnace tube for wafer thin film deposition and a method provided by the present invention are:

[0023] 1. By setting a baffle with the same or similar surface area as the product wafer in the first placement area and / or the third placement area and on the side close to the second placement area, the product wafer close to the baffle and the product wafer far from the baffle obtain the same reaction gas, so as to ensure the consistency and uniformity of the film thickness formed on each product wafer in the tube body.

[0024] 2. The baffle can be reused to reduce the cost of use.

[0025] 3. Improve the reliability of semiconductor production. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of a furnace tube for wafer thin film deposition according to an embodiment of the present invention;

[0027] Figure 2 A schematic diagram of a structure in which wafers and baffles are placed on a wafer boat according to an embodiment of the present invention;

[0028] Figure 3 A schematic diagram of a structure in which wafers and baffles are placed on a wafer boat according to another embodiment of the present invention;

[0029] Figure 4 A schematic diagram of the structure of baffles with different surface areas in the embodiments provided by the present invention;

[0030] Figure 5 A flow chart of a method for wafer thin film deposition according to an embodiment of the present invention;

[0031] Figure 6 A comparison diagram of the thickness of the film formed after the product wafer is reacted when the baffle in this embodiment is used in the furnace tube and the baffle in the prior art is used;

[0032] Figure 7 A schematic diagram of the structure of the baffle of the embodiment provided by the present invention after multiple uses;

[0033] Figure 8 A schematic diagram of the structure of the embodiment provided by the present invention after the first etching of the used baffle;

[0034] Fig. 9 A schematic diagram of the structure of the embodiment provided by the present invention after the used baffle is etched for the second time;

[0035] Fig.10 This is a schematic diagram of the structure of the embodiment provided by the present invention after the used baffle is etched for the third time.

[0036] Reference numerals:

[0037] Wafer boat 1 , first placement area 11 , second placement area 12 , third placement area 13 , tube body 2 , baffle 3 , patterned baffle 31 , product wafer 4 , control wafer 5 , gas pipeline 6 , exhaust hole 61 , and carrier platform 7 . DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be understood by people with general skills in the field to which the present invention belongs. "Including" and similar words used in this article mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects.

[0039] In the prior art, due to the characteristics of the plasma atomic layer deposition reaction furnace tube, baffles need to be installed on the top and bottom of the wafer boat. However, the baffles commonly used in the prior art are wafers with a flat surface area, without any pattern thereon, and with a small surface area. Therefore, the baffle surface has a small adsorption capacity for the reaction gas. However, the product wafer has various patterns on its surface and a large surface area, and its adsorption capacity for the reaction gas is stronger than that of the baffle. This will cause the product wafer close to the baffle to receive more reaction gas, and the product wafer far from the baffle to receive relatively less reaction gas, so that the thickness of the film formed by the product wafer close to the baffle is relatively high, and the thickness of the film formed by the product wafer far from the baffle is relatively thin, resulting in relatively poor uniformity of the film formed by the product wafers in the entire furnace tube, and the uniformity of the film formed by the product wafers between each furnace tube is also relatively poor. The fluctuation of the uniformity of the film formed by the product wafer will affect subsequent etching processes.

[0040] refer to Figure 1 and Figure 2 As shown, in order to solve the above problems, an embodiment of the present invention provides a furnace tube for wafer thin film deposition to improve the uniformity of thin film formation on each product wafer 4 in the furnace tube.

[0041] Specifically, the furnace tube for wafer thin film deposition includes a wafer boat 1, a tube body 2 and a baffle 3. The tube body 2 is the main structure of the furnace tube, the wafer boat 1 is arranged in the tube body 2, and a carrier 7 is arranged at the bottom of the wafer boat 1, and the carrier 7 can drive the wafer boat 1 to rotate along its axial direction to ensure that each of the product wafers 4 is uniformly in contact with the reaction gas. The wafer boat 1 is sequentially provided with a first placement area 11, a second placement area 12 and a third placement area 13 along its axial direction, and the first placement area 11 and the third placement area 13 are respectively located at the two ends of the wafer boat 1, and the second placement area 12 is located in the middle area of ​​the wafer boat 1 for placing the product wafer 4.

[0042] A plurality of baffles 3 are arranged in the first placement area 11 and the third placement area 13, and the baffles 3 placed in the first placement area 11 and / or the third placement area 13 and close to the second placement area 12 have the same or similar surface area as the product wafer 4. It is worth noting that the second placement area 12 is only arranged between the first placement area 11 and the third placement area 13, and is located in the middle of the wafer boat 1. In addition, the baffles 3 having the same or similar surface area as the product wafer 4 can be obtained by selecting the baffles 3 having the smallest difference in surface area with the product wafer 4 from a series of baffles 3 with different surface areas.

[0043] In this embodiment, the first placement area 11 and the third placement area 13 are both provided with the baffle 3 having the same or similar surface area as the product wafer 4 on one side close to the second placement area 12 to prevent the product wafer 4 close to the baffle 3 from absorbing more reaction gas.

[0044] In some embodiments, the blocking piece 3 having the same or similar surface area as the product wafer 4 may be disposed on a side of the first placement area 11 close to the second placement area 12 or on a side of the third placement area 13 close to the second placement area 12 .

[0045] It should be noted that, by etching a pattern on the surface of the baffle 3 so that the surface area of ​​the baffle 3 is the same or similar to the surface area of ​​the product wafer 4, it is avoided that the product wafer 4 near the baffle 3 absorbs more reaction gas due to the smaller surface area of ​​the baffle 3, thereby improving the consistency and uniformity of the film thickness formed on each product wafer 4 in the tube body 2.

[0046] Continue to refer Figure 2 As shown, in some embodiments, the baffle 3 includes a patterned baffle 31, and the patterned baffle 31 is arranged in the first placement area 11 and / or the third placement area 13 and close to one side of the second placement area 12, and the surface area of ​​the patterned baffle 31 is the same as or similar to the surface area of ​​the product wafer 4.

[0047] Specifically, patterns are etched on the surfaces of a plurality of the baffles 3 to form the patterned baffles 31 , and the patterns on the patterned baffles 31 are completely the same as or similar to the patterns on the product wafer 4 .

[0048] In this embodiment, the pattern of the patterned baffle 31 is set to be exactly the same or similar to the pattern of the product wafer 4, so that the surface area of ​​the patterned baffle 31 is the same or similar to the surface area of ​​the product wafer 4, so that the reaction gas adsorbed by the product wafer 4 close to the patterned baffle 31 will not increase, thereby ensuring the consistency and uniformity of the thickness of the thin film formed on each of the product wafers 4 in the tube body 2.

[0049] In some embodiments, the product wafer 4 is placed on the first placement area 11 and / or the third placement area 13 and close to the second placement area 12. In this embodiment, the product wafer 4 is used as the baffle 3 to prevent the product wafer 4 close to the baffle 3 from absorbing more reaction gas.

[0050] refer to Figure 1 and Figure 3 As shown, in some embodiments, a control piece 5 is further disposed on the wafer boat 1 , and the control piece 5 is inserted in the second placement area 12 .

[0051] In this embodiment, the control chip 5 is inserted in the second placement area 12 to test whether the performance in the tube body 2 is stable, whether the production environment is clean, etc., and the production line status can be known by monitoring the relevant parameters of the machine operation. Before the production line is put into production, the control chip 5 can be used to test whether the furnace tube is reliable in advance, thereby reducing production costs. After the production line is put into production, the control chip 5 is put into the production line together with the product wafer 4, and by detecting the status of the control chip 5, it can be determined whether the production of this batch is standard.

[0052] refer to Figure 1As shown, in some embodiments, the furnace tube also includes a gas pipe 6 arranged near the inner wall of the tube body 2, the side wall of the tube body 2 begins to have a through hole, the gas pipe 6 is penetrated through the through hole and the through hole is sealed, one end of the gas pipe 6 extends into the tube body 2, the extension direction of the gas pipe 6 is parallel to the axial direction of the tube body 2, and a plurality of exhaust holes 61 are arranged on the gas pipe 6 along the axial direction and spaced in sequence, and the plurality of exhaust holes 61 are used to uniformly introduce the reaction gas into the tube body 2.

[0053] In some embodiments, the wafer boat 1 is provided with a plurality of support members spaced in sequence along its axial direction, and the plurality of support members are divided into the first placement area 11, the second placement area 12, and the third placement area 13 according to the upper, middle, and lower regional positions, indicating that the first placement area 11, the second placement area 12, and the third placement area 13 are all composed of a plurality of support members, and the first placement area 11 is located in the upper end area of ​​the wafer boat 1, the second placement area 12 is located in the middle area of ​​the wafer boat 1, and the third placement area 13 is located in the lower end area of ​​the wafer boat 1. The baffle 3 and the product wafer 4 are both placed on the support members at different positions.

[0054] refer to Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, in another embodiment disclosed in the present invention, a method for wafer thin film deposition is provided, the method is applied to the furnace tube for wafer thin film deposition disclosed in the above embodiment, and the method comprises the following steps:

[0055] S501: placing a number of product wafers in the second placement area.

[0056] Specifically, the second placement area 12 is composed of a plurality of support members arranged at intervals, and a plurality of product wafers 4 are sequentially placed on the plurality of support members where the second placement area 12 is located.

[0057] S502: placing a baffle on the first placement area and / or the third placement area, and the baffle placed on the first placement area and / or the third placement area and close to the second placement area has a surface area that is the same as or similar to that of the product wafer.

[0058] In this step, at least one baffle 3 having the same or similar surface area as the product wafer 4 may be arranged on the side of the first placement area 11 close to the second placement area 12. Alternatively, at least one baffle 3 having the same or similar surface area as the product wafer 4 may be arranged on the side of the third placement area 13 close to the second placement area 12.

[0059] It should be noted that, in this embodiment, the baffle kit for the furnace tube is included, and the baffle kit includes a series of baffles 3 with different surface areas, and there is at least one baffle 3 of each surface area.

[0060] Specifically, a deposition etching method may be used in advance to etch patterns on the surface of the baffle 3 to form a series of baffles 3 with different surface areas, so that the surface area of ​​some of the baffles 3 is the same as or similar to the surface area of ​​the product wafer 4 .

[0061] In some embodiments, a series of baffles 3 with different surface areas may be prepared in advance to calibrate the surface area of ​​each baffle 3 , so as to obtain a portion of the baffles 3 having the same or similar surface area as the product wafer 4 .

[0062] Then, the surface area of ​​the product wafer 4 is detected or calculated; and all the baffles 3 having the same or similar surface area as the product wafer 4 are placed in the first placement area 11 and the second placement area 12 .

[0063] S503: Introducing reaction gas into the tube body to form a thin film on the product wafer.

[0064] In this step, the tube body 2 is connected to a gas pipeline 6, and the reaction gas is evenly transported into the tube body 2 by the gas pipeline 6 to ensure the uniform distribution of the reaction gas in the tube body 2, thereby improving the uniformity of the thin film formed on the product wafer 4 and the consistency of the thin film formed on each of the product wafers 4.

[0065] In this embodiment, the baffle 3 with the same surface area as the product wafer 4 is arranged on the first placement area 11 and / or the third placement area 13 near the second placement area 12, so that the amount of reaction gas adsorbed by the baffle 3 near the product wafer 4 is the same as that adsorbed by the product wafer 4, thereby avoiding an increase in the amount of reaction gas adsorbed by the product wafer 4 near the baffle 3, thereby ensuring the consistency and uniformity of the thickness of the thin film formed on each of the product wafers 4 in the tube body 2, and improving the reliability of semiconductor production.

[0066] refer to Figure 1 , Figure 4 and Figure 6As shown, 50 product wafers 4 are placed at positions 61-110 in the second area of ​​the tube body 2. When the baffle plate 3 described in this embodiment is not added to the tube body 2 (BSL), the difference in film thickness (WTW range) between the product wafers 4 after the reaction is 5A. When the baffle plate 3 described in this embodiment is added to the tube body 2 (CIP), the difference in film thickness (WTW range) between the product wafers 4 after the reaction is 2A. It can be seen that by adding the baffle plate described in this embodiment to the tube body, the uniformity of the film thickness between the product wafers 4 can be improved by 60%.

[0067] In addition, position 60 is located at the upper end of the tube body 2, and position 110 is located at the lower end of the tube body 2; Figure 6 It can be seen from the figure that the product wafer 4 at the upper end of the tube body 2 has a greater impact. In order to solve this problem, the baffles 3 in this embodiment can be completely arranged at the upper end of the tube body 2 (the first area).

[0068] In this embodiment, each of the baffles 3 can be reused, thereby reducing the use cost.

[0069] Specifically, combined Figures 7 to 10 As shown, according to the experimental data, it can be concluded that the baffle 3 can be recycled at least 7 times, and the pattern structure on the surface of the baffle 3 can still be maintained.

[0070] like Figure 7 As shown, after the baffle 3 in this embodiment has been used for many times, the convex structure ( Figure 7 The width of the two convex structures in the left picture is 62.65nm, and the convex structure in the edge area of ​​the baffle 3 ( Figure 7 The width of the two raised structures in the right picture is 64.34nm.

[0071] like Figure 8 As shown, after the first etching process is performed on the baffle 3, the width of the protruding structure in the edge area of ​​the baffle 3 is 61.64 nm.

[0072] like Fig. 9 As shown, after the baffle 3 is subjected to a second etching process, the convex structure ( Fig. 9 The width of the four raised structures in the left picture is 59.81nm, and the raised structures in the edge area of ​​the baffle 3 ( Fig. 9 The width of the four raised structures in the right picture is 58.32nm.

[0073] like Fig.10As shown, after the baffle 3 is etched for the third time, the convex structure in the middle area of ​​the baffle 3 ( Fig.10 The width of the two convex structures in the left picture is 56.15nm, and the convex structure in the edge area of ​​the baffle 3 ( Fig.10 The width of the two raised structures in the right image is 55.8nm.

[0074] Therefore, the baffle 3 in this embodiment can still maintain the pattern structure on its surface after being used multiple times, which greatly saves costs. Moreover, after being used multiple times, the baffle 3 can be gradually restored to its original pattern structure through etching and cleaning to ensure the recycling of the baffle 3.

[0075] Although the embodiments of the present invention are described in detail above, it is obvious to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as described in the claims. Moreover, the present invention described herein may have other embodiments and may be implemented or realized in a variety of ways.

Claims

1. A furnace tube for wafer thin film deposition, It is characterized in that It includes a crystal boat, a tube body and a baffle; The wafer boat is arranged in the tube body, and the wafer boat is provided with a first placement area, a second placement area and a third placement area in sequence along its axial direction, and the first placement area and the third placement area are respectively located at two ends of the wafer boat, and the second placement area is used to place product wafers; Several baffles are arranged in the first placement area and the third placement area, and the baffles placed in the first placement area and / or the third placement area and close to the second placement area have the same or similar surface area as the product wafer.

2. The furnace tube for wafer thin film deposition according to claim 1, It is characterized in that The baffle includes a patterned baffle, which is arranged on the first placement area and / or the third placement area and close to one side of the second placement area, and the surface area of ​​the patterned baffle is the same as or similar to the surface area of ​​the product wafer.

3. The furnace tube for wafer thin film deposition according to claim 2, It is characterized in that The surfaces of the plurality of baffles are all etched with patterns to form patterned baffles with different surface areas, and the surface area of ​​at least one of the patterned baffles is the same as or similar to the surface area of ​​the product wafer.

4. The furnace tube for wafer thin film deposition according to claim 1, It is characterized in that It also includes a control piece arranged on the wafer boat, and the control piece is placed in the second placement area.

5. The furnace tube for wafer thin film deposition according to claim 1, It is characterized in that The product wafer is placed on the first placement area and / or the third placement area and close to the second placement area.

6. The furnace tube for wafer thin film deposition according to claim 1, It is characterized in that The surface areas of the baffles placed in the first placement area and the third placement area are the same as or similar to those of the product wafer.

7. A baffle kit for a furnace tube, It is characterized in that It comprises a series of baffles with different surface areas, and there is at least one baffle with each surface area.

8. The baffle kit for furnace tube according to claim 7, It is characterized in that A deposition etching method is used to etch a pattern on the surface of the baffle, so that the surface area of ​​a part of the baffle is the same as or similar to the surface area of ​​the product wafer.

9. A method for wafer thin film deposition, It is characterized in that Using the furnace tube according to any one of claims 1 to 6 and the baffle kit for the furnace tube according to claim 7 or 8, the method comprises: placing a plurality of product wafers in the second placement area; Placing baffles on the first placement area and the third placement area, and the baffle placed on the first placement area and / or the third placement area and close to the second placement area has a surface area that is the same as or similar to that of the product wafer; Reaction gas is introduced into the tube body to form a thin film on the product wafer.

10. The method for wafer thin film deposition according to claim 9, It is characterized in that Placing baffles on the first placement area and the third placement area, wherein the baffle placed on the first placement area and / or the third placement area and close to the second placement area has the same or similar surface area as the product wafer, comprises: Selecting the baffle sheet from the baffle sheet kit, the baffle sheet having the same or similar surface area as the product wafer; At least one baffle having a surface area that is the same as or similar to that of the product wafer is placed in the first placement area and / or the second placement area and close to a side of the second placement area.

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