Furnace tube for wafer film deposition

Abstract

The utility model provides a furnace tube for wafer film deposition, which comprises a furnace body provided with an annular furnace wall, the diameter of the furnace wall is gradually reduced from the bottom of the furnace body to the top of the furnace body, and an air inlet hole and an air outlet hole are formed in the bottom, close to the furnace body, of the furnace wall; and the wafer boat is rotatably arranged in the furnace body, and the wafer boat is used for bearing a wafer. According to the furnace tube for wafer film deposition provided by the utility model, the furnace wall of the furnace body is obliquely arranged, so that the diameter of the furnace wall is gradually reduced from the bottom of the furnace body to the top of the furnace body, and when reaction gas is introduced into the furnace body through the gas inlet hole, the gas pressure at the top of the furnace body is greater than the gas pressure at the bottom of the furnace body; therefore, the pressure when the gas flow of the reaction gas flows through the top of the furnace body is increased, the problem that the thickness distribution of a wafer deposition film in a wafer boat is not uniform is effectively solved, the growth uniformity of the wafer film is improved, and the yield of subsequent products is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor manufacturing, in particular to a furnace tube for wafer thin film deposition. Background Art

[0002] The method of growing thin films by furnace tube is a common means in semiconductor manufacturing. This method can grow dozens or even hundreds of products at a time, with relatively low cost. Considering the characteristics of the furnace tube process where multiple wafers are processed simultaneously, the uniformity between wafers (Wafer to wafer uniformity, WTW U%) usually needs to be considered when growing thin films on the furnace tube machine.

[0003] In the existing furnace tubes, the reaction gas generally enters from the bottom of the furnace tube and is transported from bottom to top throughout the furnace tube to deposit and grow thin films on the wafers. When the reaction gas is introduced from the bottom, the reaction gas will be continuously consumed at the bottom of the furnace tube, resulting in a smaller amount of reaction gas at the top of the furnace tube than at the bottom. This will cause differences in the shape and thickness of the thin films deposited on the wafer surfaces in the furnace tube. Specifically, the thickness of the thin film deposited on the wafer surface near the bottom end of the furnace tube is relatively thick, and the thickness of the thin film formed on the wafer surface near the top of the furnace tube is relatively thin. Such different shape distributions pose great challenges to subsequent processes and even seriously affect the yield of the final product in severe cases. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a furnace tube for wafer thin film deposition, which improves the uniformity of wafer thin film growth and ensures the yield of subsequent products.

[0005] To achieve the above purpose, in the first aspect, the utility model provides a furnace tube for wafer thin film deposition, comprising:

[0006] A furnace body with a circumferentially arranged furnace wall, the diameter of the furnace wall gradually decreasing from the bottom to the top of the furnace body, and an air inlet hole and an air outlet hole are opened on the furnace wall near the bottom of the furnace body;

[0007] A susceptor rotatably arranged in the furnace body, and the susceptor is used for carrying wafers.

[0008] The beneficial effect of the furnace tube for wafer thin film deposition provided by the utility model is that: by obliquely arranging the furnace wall of the furnace body so that the diameter of the furnace wall gradually decreases from the bottom to the top of the furnace body, when the reaction gas is introduced into the furnace body through the air inlet hole, the air pressure at the top of the furnace body will be greater than the air pressure at the bottom of the furnace body, thereby increasing the pressure of the reaction gas flow when passing through the top of the furnace body, effectively solving the problem of uneven thickness distribution of the thin films deposited on the wafers in the susceptor, improving the uniformity of wafer thin film growth, and ensuring the yield of subsequent products.

[0009] In some embodiments, the furnace tube for wafer thin film deposition further includes a pressure dividing sleeve disposed in the furnace body;

[0010] The pressure dividing sleeve is sleeved on the susceptor, and the diameter of the pressure dividing sleeve gradually decreases from the bottom of the furnace body to the top of the furnace body. The pressure dividing sleeve is used to adjust the air pressure in the furnace body. The beneficial effect is that by arranging the pressure dividing sleeve in the furnace body and the diameter of the pressure dividing sleeve gradually decreasing from the bottom of the furnace body to the top of the furnace body, it further ensures the rapid distribution of the reaction gas flow, so that the reaction gas is rapidly and evenly distributed in the furnace body.

[0011] In some embodiments, the furnace tube for wafer thin film deposition further includes an inlet pipe;

[0012] The inlet pipe penetrates through the intake hole, and one end extends between the pressure dividing sleeve and the susceptor. The inlet pipe is used to transport the reaction gas between the pressure dividing sleeve and the susceptor. The beneficial effect is that by extending one end of the inlet pipe between the pressure dividing sleeve and the susceptor, when the inlet pipe accesses the reaction gas, the reaction gas can be directly discharged between the pressure dividing sleeve and the susceptor to improve the growth efficiency of the wafer thin film.

[0013] In some embodiments, an annular connecting convex portion is provided on the inner wall of the furnace body, and the connecting convex portion is close to the bottom of the furnace body;

[0014] The pressure dividing sleeve is connected to the connecting convex portion.

[0015] In some embodiments, there is a gap between the pressure dividing sleeve and the furnace wall to form a gas channel, and the air outlet hole is arranged close to the connecting convex portion and is in communication with the gas channel. The beneficial effect is that the pressure dividing sleeve is connected to the connecting convex portion, and a gap is provided between the pressure dividing sleeve and the furnace wall. When the reaction gas is introduced into the furnace body, the reaction gas will flow from the bottom of the furnace body to the top of the furnace body, and then be discharged from the air outlet hole through the gap, realizing the control of the flow trajectory of the reaction gas.

[0016] In some embodiments, the susceptor includes a support frame and a carrier;

[0017] The support frame is a hollow annular structure;

[0018] The carrier is disposed on the inner wall of the support frame for carrying wafers.

[0019] In some embodiments, a plurality of the carriers are spaced along the axis of the support frame on the inner side wall of the support frame, and at least three of the carriers located on the same horizontal plane form a support surface for carrying wafers.

[0020] In some embodiments, the carrier is inclined towards the bottom of the furnace body, and a plurality of support portions are provided at intervals along the axial direction of the carrier. The support portions located on the same horizontal plane enclose the support surface. The beneficial effect is that by inclining the carrier towards the bottom of the furnace body and providing a plurality of support portions at intervals along the axial direction of the carrier, and the support portions located on the same horizontal plane enclose the support surface, different-sized support surfaces can be formed, realizing the loading of wafers of different specifications and improving the applicability of the susceptor.

[0021] In some embodiments, the support frame includes a connecting plate and a connecting rod;

[0022] The connecting plate is of a disc-shaped structure;

[0023] At least three connecting rods are arranged on the connecting plate at intervals and in a ring shape;

[0024] The carrier is arranged on the inner side wall of the connecting rod.

[0025] In some embodiments, the side wall of the connecting plate extends towards the pressure dividing sleeve and is rotatably connected to the pressure dividing sleeve, and the connecting plate divides the furnace body into a reaction chamber and an installation chamber;

[0026] An air inlet channel is provided on the pressure dividing sleeve, and the air inlet channel conducts the reaction chamber and the installation chamber;

[0027] The inlet pipe passes through the air inlet hole, and one end of the inlet pipe is communicated with the air inlet channel for delivering reaction gas into the reaction chamber. The beneficial effect is that by extending the side wall of the connecting plate towards the pressure dividing sleeve and rotatably connecting it to the pressure dividing sleeve, the furnace body is divided into a reaction chamber and an installation chamber, reducing the reaction space in the furnace body. The reaction gas can be directly delivered to the susceptor through the air inlet channel, thereby improving the efficiency of gas delivery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 FIG. 1 is a schematic structural diagram of a furnace tube for wafer thin film deposition according to the first embodiment provided by the present invention;

[0029] Figure 2 FIG. 2 is a schematic structural diagram of a furnace tube for wafer thin film deposition according to the second embodiment provided by the present invention;

[0030] Figure 3 FIG. 3 is a schematic structural diagram of a furnace tube for wafer thin film deposition according to the third embodiment provided by the present invention;

[0031] Figure 4 FIG. 4 is a schematic structural diagram of a susceptor according to the embodiment provided by the present invention;

[0032] Figure 5Schematic diagram of the carrier in the first embodiment provided by the present utility model;

[0033] Figure 6 Schematic diagram of the carrier in the second embodiment provided by the present utility model;

[0034] Figure 7 Schematic diagram of the furnace tube for wafer thin film deposition in the fourth embodiment provided by the present utility model;

[0035] Figure 8 is Figure 7 The enlarged view of part A in

[0036] Reference numerals:

[0037] 1, furnace body; 11, furnace wall; 12, air inlet hole; 13, air outlet hole; 14, connecting convex part; 15, reaction chamber; 16, installation chamber; 2, boat; 21, support frame; 211, connecting plate; 212, connecting rod; 22, carrier; 221, support part; 3, pressure dividing sleeve; 31, gas channel; 32, air inlet channel; 33, groove; 4, inlet pipe; 5, base; 6, rotating mechanism. Detailed implementation manners

[0038] In order to make the objectives, technical solutions and advantages of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings of the present utility model. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model. Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings understood by those of ordinary skill in the art in the field to which the present utility model belongs. The words such as "including" used herein mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. The "connection" described herein can be a direct connection or an indirect connection, that is, a connection through an intermediate object, unless otherwise specified.

[0039] In view of the problems existing in the prior art, the embodiments of the present utility model provide a furnace tube for wafer thin film deposition. Refer to Figure 1As shown in the figure, the furnace tube for wafer thin film deposition includes a furnace body 1 and a boat 2. Among them, the furnace body 1 has a furnace wall 11 arranged in a ring shape, and the diameter of the furnace wall 11 gradually decreases from the bottom of the furnace body 1 to the top of the furnace body 1, so that the furnace body 1 has a frustum-shaped structure. An air inlet hole 12 and an air outlet hole 13 are opened on the furnace wall 11 near the bottom of the furnace body 1. The air inlet hole 12 is used to introduce reaction gas into the furnace body 1, and the air outlet hole 13 is used to discharge the reacted gas. The boat 2 is arranged in the furnace body 1 and is connected to the base 5. The boat 2 is used to carry wafers.

[0040] In this embodiment, the furnace wall 11 of the furnace body 1 is inclined towards the axis of the furnace body 1, so that the diameter of the furnace wall 11 gradually decreases from the bottom of the furnace body 1 to the top of the furnace body 1, forming a hollow frustum-shaped structure. When reaction gas is introduced into the furnace body 1 through the air inlet hole 12, due to the action of the structure of the furnace body 1 itself, the air pressure at the top of the furnace body 1 will be greater than the air pressure at the bottom of the furnace body 1, thereby increasing the pressure of the reaction gas flowing through the top of the furnace body 1. This effectively solves the problem of uneven thickness distribution of the thin film deposited on the wafers in the boat 2, improves the uniformity of wafer thin film growth, and ensures the yield of subsequent products.

[0041] Reference Figure 2 As shown in the figure, in some embodiments, the furnace tube for wafer thin film deposition further includes a pressure dividing sleeve 3 arranged in the furnace body 1. The pressure dividing sleeve 3 has a hollow tubular structure and is sleeved on the boat 2, and the diameter of the pressure dividing sleeve 3 gradually decreases from the bottom of the furnace body 1 to the top of the furnace body 1 to form a frustum-shaped structure. The pressure dividing sleeve 3 is used to adjust the air pressure in the furnace body 1.

[0042] In this embodiment, by arranging the hollow and frustum-shaped pressure dividing sleeve 3 in the furnace body 1, the gas pressure in the furnace body 1 is further changed, so that the reaction gas is quickly and evenly distributed in the furnace body 1.

[0043] Reference Figure 3 As shown in the figure, in some embodiments, the furnace tube for wafer thin film deposition further includes an inlet pipe 4. The inlet pipe 4 passes through the air inlet hole 12 and is hermetically connected to the air inlet hole 12. One end of the inlet pipe 4 extends between the pressure dividing sleeve 3 and the boat 2, and the other end of the inlet pipe 4 is communicated with an external gas supply device. The gas supply device is used to provide reaction gas and transport the reaction gas to between the pressure dividing sleeve 3 and the boat 2 through the inlet pipe 4.

[0044] Continue to refer to Figure 3As shown, in some embodiments, an annular connecting convex portion 14 is provided on the inner wall of the furnace body 1. The connecting convex portion 14 is close to the bottom of the furnace body 1 and is spaced from the bottom of the furnace body 1 by a certain distance for arranging the intake pipe 4. The pressure dividing sleeve 3 is fixedly connected to the connecting convex portion 14 so that the pressure dividing sleeve 3 is fixedly arranged in the furnace body 1.

[0045] Further, a gap is formed between the pressure dividing sleeve 3 and the furnace wall 11 to form a gas passage 31. The air outlet hole 13 is arranged close to the connecting convex portion 14 and is communicated with the gas passage 31.

[0046] In this embodiment, both the intake hole 12 and the air outlet hole 13 are arranged close to the bottom of the furnace body 1. The reaction gas enters the furnace body 1 through the intake hole 12 and diffuses from the bottom of the furnace body 1 towards the top of the furnace body 1 to react with the wafers on the susceptor 2. Finally, the reacted gas is discharged through the gas passage 31 and the air outlet hole 13.

[0047] Reference Figure 4 As shown, in some embodiments, the susceptor 2 includes a support frame 21 and a carrier 22. The support frame 21 is a hollow annular structure, and the carrier 22 is arranged on the inner wall of the support frame 21 for carrying wafers.

[0048] Specifically, a plurality of the carriers 22 are arranged on the inner side wall of the support frame 21 at intervals along the axis of the support frame 21, and at least three of the carriers 22 located on the same horizontal plane form a support surface for carrying wafers.

[0049] In this embodiment, the number of the carriers 22 located on the same horizontal plane is three, which not only provides stable support for the wafers but also reduces the contact area with the wafers, thereby reducing the probability of generating contamination particles due to rubbing against the wafers.

[0050] Further, the carrier 22 is inclined towards the bottom of the furnace body 1, and a plurality of support portions 221 are spaced along the axial direction of the carrier 22. The support portions 221 located on the same horizontal plane enclose the support surface.

[0051] In this embodiment, the carrier 22 is inclined towards the bottom of the furnace body 1 to ensure the distance between adjacent support surfaces and improve the uniformity during the diffusion of the reaction gas. And because a plurality of support portions 221 are spaced along the axial direction of the carrier 22, the support portions 221 located on the same horizontal plane enclose the support surface, and the support surface closer to the top of the furnace body 1 is larger than the support surface closer to the bottom of the furnace body 1, so that it can be applicable to the support of wafers of different specifications and improve the applicability of the susceptor 2.

[0052] Reference Figure 5 As shown, in some embodiments, the support portion 221 is an "L"-shaped groove formed on the side wall of the carrier 22. By setting the support portion 221 as an "L"-shaped groove, the stability of the wafer support is ensured.

[0053] Reference Figure 6 As shown, in some embodiments, the support portion 221 is an arc-shaped groove formed on the side wall of the carrier 22. By setting the support portion 221 as an arc-shaped groove, the contact area with the wafer is further reduced.

[0054] Reference Figure 4 、 Figure 7 and Figure 8 As shown, in some embodiments, the support frame 21 includes a connecting plate 211 and a connecting rod 212. Among them, the connecting plate 211 is a disc-shaped structure, the connecting plate 211 is arranged on the base 5 located in the furnace body 1, and at least three connecting rods 212 are arranged on the connecting plate 211 at intervals and in a ring shape to form a cylindrical frame structure. The carrier 22 is arranged on the inner side wall of the connecting rod 212.

[0055] Furthermore, the side wall of the connecting plate 211 extends towards the pressure dividing sleeve 3 and is rotatably connected to the pressure dividing sleeve 3 to divide the furnace body 1 into an upper reaction chamber 15 and a lower installation chamber 16. An air inlet channel 32 is formed on the pressure dividing sleeve 3, and one end of the air inlet pipe 4 arranged at the air inlet hole 12 is communicated with the air inlet channel 32 through the installation chamber 16 for conveying reaction gas towards the crystal boat 2 in the reaction chamber 15.

[0056] In this embodiment, by extending the side wall of the connecting plate 211 towards the pressure dividing sleeve 3, the furnace body 1 is divided into an upper reaction chamber 15 and a lower installation chamber 16, reducing the reaction space in the furnace body 1. The reaction gas can be directly conveyed towards the crystal boat 2 through the air inlet channel 32, thereby improving the gas conveying efficiency. Specifically, an annular groove 33 is formed on the inner side wall of the pressure dividing sleeve 3, the side wall of the connecting plate 211 extends towards the pressure dividing sleeve 3 into the groove 33 and maintains a relatively small gap with the groove 33, as long as this gap does not affect the rotation of the connecting plate 211.

[0057] In some embodiments, the furnace tube for wafer thin film deposition further includes a base 5 and a rotating mechanism 6 arranged at the bottom of the furnace body 1. Among them, the base 5 is located in the furnace body 1 for supporting the crystal boat 2, the rotating mechanism 6 is located outside the furnace body 1 and is magnetically fluid-sealedly connected to the base 5. When the rotating mechanism 6 rotates, it can drive the crystal boat 2 to rotate in the reaction chamber 15.

[0058] As described above, it is only the specific implementation manner of the embodiments of the present application. However, the protection scope of the embodiments of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the embodiments of the present application should be covered within the protection scope of the embodiments of the present application. Therefore, the protection scope of the embodiments of the present application shall be subject to the protection scope of the claims.

Claims

1. A furnace tube for wafer thin film deposition, characterized in that: include: The furnace body has a furnace wall arranged in an annular shape, the diameter of the furnace wall gradually decreases from the bottom of the furnace body to the top of the furnace body, and the furnace wall is provided with an air inlet and an air outlet near the bottom of the furnace body; A wafer boat is rotatably disposed in the furnace body, and is used to carry wafers; It also includes a pressure dividing sleeve arranged in the furnace body; The pressure dividing sleeve is sleeved on the wafer boat, and the diameter of the pressure dividing sleeve gradually decreases from the bottom of the furnace body to the top of the furnace body. The pressure dividing sleeve is used to adjust the gas pressure in the furnace body.

2. The furnace tube according to claim 1, characterized in that Also includes the intake duct; The air inlet pipe is arranged through the air inlet hole, and one end of the air inlet pipe extends between the pressure dividing sleeve and the wafer boat. The air inlet pipe is used to transport the reaction gas to between the pressure dividing sleeve and the wafer boat.

3. The furnace tube according to claim 1, characterized in that The inner wall of the furnace body is provided with an annular connecting protrusion, and the connecting protrusion is close to the bottom of the furnace body; The pressure dividing sleeve is connected to the connecting protrusion.

4. The furnace tube according to claim 3, characterized in that A gap is provided between the pressure dividing sleeve and the furnace wall to form a gas channel, and the gas outlet hole is arranged close to the connecting protrusion and communicates with the gas channel.

5. The furnace tube according to any one of claims 1 to 4, characterized in that: The wafer boat comprises a support frame and a bearing member; The support frame is a hollow annular structure; The carrier is arranged on the inner wall of the support frame for carrying the wafer.

6. The furnace tube according to claim 5, characterized in that A plurality of the carriers are arranged on the inner side wall of the support frame at intervals along the axis of the support frame, and at least three of the carriers are arranged on the same horizontal plane to form a supporting surface for carrying wafers.

7. The furnace tube according to claim 6, characterized in that The bearing member is arranged obliquely toward the bottom of the furnace body, and the bearing member is provided with a plurality of support parts spaced apart along its axial direction, and the support parts located on the same horizontal plane are arranged to form the support surface.

8. The furnace tube according to claim 6 or 7, characterized in that: The support frame includes a connecting plate and a connecting rod; The connecting plate is a disc-shaped structure; At least three of the connecting rods are arranged on the connecting plate in an annular manner at intervals; The bearing member is arranged on the inner side wall of the connecting rod.

9. The furnace tube according to claim 8, characterized in that The side wall of the connecting plate extends toward the pressure dividing sleeve and is rotatably connected to the pressure dividing sleeve, and the connecting plate divides the furnace body into a reaction chamber and an installation chamber; The pressure dividing sleeve is provided with an air inlet channel, and the air inlet channel connects the reaction chamber and the installation chamber; An air inlet pipe is arranged through the air inlet hole, and one end of the air inlet pipe is communicated with the air inlet channel for conveying reaction gas into the reaction chamber.

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