TWM610353U - Vertical furnace and vertical boat used therefor - Google Patents

Abstract

The present utility model provides a new type of boat used in a vertical furnace. The slots in such boat have improved surface roughness and tilt angle. With the new boat herein, the contact area with wafers can be reduced, and thus the defects of the wafer edge and the overall uniformity of the film during the process are improved.

Description

Vertical furnace tube and vertical wafer boat used for it

This creation is about a vertical wafer boat that carries wafers in a vertical furnace tube. Specifically, it is a vertical wafer boat used in processes such as heat treatment, oxidation, diffusion, and CVD (Chemical Vapor Deposition).

Furnace tube equipment is widely used in many processes in the semiconductor manufacturing process, such as diffusion deposition, oxidation, annealing, and so on. Among them, the diffusion deposition process is mainly used to produce a thin film on a substrate (such as a semiconductor wafer). When the process is performed through a vertical furnace tube, it is generally desirable to make the film on the substrate have better uniformity and fewer surface defects.

In the process of wafer processing, it is usually necessary to introduce the reaction gas into the furnace tube and diffuse the reaction gas on the surface of the substrate in the furnace tube to produce the required thin film. Therefore, it is very important that the reaction gas in the furnace tube is uniformly distributed on the substrate. Generally speaking, furnace tube equipment can be divided into horizontal furnace tubes and vertical furnace tubes. Among them, the reactor of the vertical furnace tube is arranged in a vertical manner, and is widely used because of its small overall footprint. In the conventional vertical furnace tube, the wafer boat carries the wafer by supporting the surface of the wafer on the horizontal groove of the wafer boat, and the reaction gas is introduced into the furnace tube cavity through a gas injector and diffused to the carrier. Wafers on the wafer boat to achieve the purpose of film formation. However, when the wafer is carried on the wafer boat of this conventional design, the contact between the wafer and the carrying surface (for example, slot) of the wafer boat Large area and complete attachment, and it is impossible for the reactive gas to react uniformly on the surface of the wafer, and defects are prone to occur at the contact between the wafer and the carrying surface, resulting in the obtained wafer surface and the thin film on the surface It may be non-ideal.

This creation was produced in this context.

In view of this, a new type of wafer boat for vertical furnace tubes is provided according to the embodiment of the invention, which includes: an upper plate body, a lower plate body, a supporting rod body, and a supporting rod body. The upper plate body is the fixed plate at the top of the vertical wafer boat; the lower plate body is the positioning plate at the bottom of the vertical wafer boat; the supporting rod body is a supporting column for strengthening the wafer boat structure; the supporting rod body has a plurality of grooves and grooves. The loading surface between the slots (also called "groove", "groove surface", or "slot") is the main structure for supporting wafers. The supporting rod body of the wafer boat and the system of three supporting rods are connected between the upper plate body part and the lower plate body part. The wafer boat is integrally arranged in the inner tube of the vertical furnace tube and extends along the extension direction of the vertical furnace tube. In addition, when the wafer is placed in the wafer boat, the wafer is horizontally supported on each carrying surface of the wafer boat.

In one embodiment, all parts of the wafer boat are made of quartz. In one embodiment, the length directions of the supporting rod body and the supporting rod body are parallel to each other, and the two ends of each rod body are connected to the plane of the upper plate body and the lower plate body respectively. In one embodiment, the groove surface on the supporting rod body of the wafer boat is an inclined surface, and the angle between the groove surface and the horizontal surface is between 8° and 10°.

According to the embodiment of the present invention, a vertical furnace tube is provided, which includes an outer tube, an inner tube, a wafer boat, and a plurality of gas injectors. The inner tube is arranged inside the outer tube. The wafer boat is arranged inside the inner tube and used to carry wafers. In one embodiment, the wafer boat has three supporting rods and one supporting rod, wherein the first supporting rod, the second supporting rod, the third supporting rod, And the supporting rods are arranged at a predetermined distance from each other. In one embodiment, the groove surfaces of the above three bearing rods are roughened by the special technique of this creation (for example, it may include the steps of groove forming, roughening, etching, cleaning, etc.), and the degree of roughening reaches Ra>10um surface roughness.

Through the following detailed description with accompanying drawings, other aspects of this creation will be clearer.

100: Vertical furnace tube

102: Outer tube

104: inner tube

106: vertical crystal boat

108: Gas Syringe

110: Gas Supply Department

112: The first bearing rod

114: second bearing rod

116: The third bearing rod

118: Support rod

120: Pedestal

122: first board body

132: second board

136: open side

138: Half arc side

140: bearing surface

142: horizontal plane

W: Wafer

With reference to the following detailed description with accompanying drawings, the described embodiments and their advantages can be more thoroughly understood. The drawings do not limit those skilled in the art to make changes in form and details of the described embodiments without departing from the spirit and scope of the embodiments.

Figure 1 is a schematic cross-sectional view of a vertical furnace tube according to an embodiment of the invention.

Figure 2 shows a side view of a vertical wafer boat according to an embodiment of the invention.

Figure 3 shows a three-dimensional view of a vertical wafer boat according to an embodiment of the invention.

FIG. 4 shows a schematic diagram of the rough surface on the trench of the vertical wafer boat according to an embodiment of the present invention.

Fig. 5 is a bottom view of a vertical wafer boat according to an embodiment of the present creation.

Fig. 6 is a top view of a vertical wafer boat according to an embodiment of the present creation.

In the drawings of this creation, component symbols may be used repeatedly to indicate similar and/or identical components.

The purpose, advantages and features of this creation can be more clearly understood from the detailed description of the following several embodiments and accompanying drawings.

In order to understand the implementation of this creation more clearly, in the following description, many specific details will be presented. However, even if part or all of these details are lacking, the disclosed embodiments can be implemented. In some cases, the conventional structure and operation method are not described in detail to avoid unnecessarily obscuring the disclosed embodiments. Although many specific details are presented for illustrative purposes, it should be understood that they are not used to limit the disclosed embodiments. When relative terms (for example, "upper" and "lower", "top" and "bottom", "inner" and "outer", etc.) are used to describe specific embodiments, these terms are only for ease of understanding. Not to be used as a restriction. In addition, it should be understood that the various embodiments shown in the figures are schematic and are not necessarily drawn to scale.

According to an embodiment of the present invention, FIG. 1 is a schematic cross-sectional view of a vertical furnace tube 100. As shown in FIG. 1, the vertical furnace tube 100 includes an outer tube 102, an inner tube 104, a vertical wafer boat 106, a gas injector 108, a gas supply part 110, and a base 120. The inner tube 104 is disposed in the outer tube 102, and the outer tube 102 and the inner tube 104 are arranged in a concentric circle, and the outer tube 102 and the inner tube 104 are separated by a predetermined distance. In some embodiments, the outer tube 102 and the inner tube 104 are made of quartz. In addition, the vertical wafer boat 106 is disposed in the inner tube 104 and on the susceptor 120, and is used to horizontally carry the wafer W to be processed on it. In some embodiments, the vertical wafer boat 106 is made of quartz. The gas injector 108 extends from the outside of the outer tube 102 to the inside of the inner tube 104 to deliver one or more reaction gases from the gas supply part 110 to the inside of the vertical furnace tube 100. Hereinafter, various embodiments of the high-yield vertical wafer boat 106 of the present invention will be described with reference to FIGS. 2 and 3.

According to an embodiment of the present invention, FIGS. 2 and 3 show a side view and a three-dimensional view of the vertical wafer boat 106, respectively. The vertical wafer boat 106 includes a rod body part and a plate body part, wherein the rod body part includes It includes a first supporting rod 112, a second supporting rod 114, a third supporting rod 116, and a supporting rod 118, and the board part includes a first board 122 and a second board 132. In one embodiment, each of the first supporting rod 112, the second supporting rod 114, and the third supporting rod 116 has the same number of grooves arranged equidistantly. In addition, each of the grooves has a carrying surface for supporting the wafer (that is, the surface in contact with the wafer, and can also be referred to as "groove teeth", "groove surface", or "slot surface (slot surface). )”). In one embodiment, the bearing surface of each groove is inclined. For example, the angle θ between the bearing surface 140 of each groove and the horizontal plane 142 is between about 8° and 10°. In addition, the bearing surface of each groove can be roughened to make the surface roughness (Ra)>10μm, as shown in the schematic diagram of FIG. 4. In one embodiment, the supporting rod body 118 is a solid quartz cylinder, which is used to provide support for the main body of the wafer boat to strengthen the overall structural strength of the wafer boat. It should be noted that although not all the grooves on the load-bearing rods are shown in FIG. 2 for the sake of brevity, it should be understood that the grooves on the load-bearing rods can be distributed throughout their entire length, or Part of the entire length.

As mentioned above, the vertical wafer boat 106 also includes a first plate body 122 and a second plate body 132. FIG. 5 shows a bottom view of the vertical wafer boat 106 (that is, a view of the bottom surface of the first plate body 122). The first plate 122 is located at the bottom of the vertical wafer boat 106 and is the base of the vertical wafer boat 106. The first plate 122 allows the vertical wafer boat 106 to be stably installed on the base (for example, the base 120) of the furnace tube (for example, the vertical furnace tube 100) as a whole. FIG. 6 is a top view of the vertical wafer boat 106 (that is, a view of the top surface of the second plate 132). The second plate 132 is located on the top of the vertical wafer boat 106 and is mainly used to stabilize the wafer boat.

In the embodiment of the present invention, the rod part (ie, the first supporting rod 112, the second supporting rod 114, the third supporting rod 116, and the supporting rod 118) are arranged on the first plate 122 And the second plate 132, and the lower end of each rod is connected with the first plate 122, and the upper end of each rod is connected with the second plate 132. In addition, each rod system is parallel to each other and spaced from each other along a circular arc arrangement. More specifically, the vertical wafer boat 106 has an opening side (such as the opening side 136 in the top view of FIG. 6) for wafers to enter and exit, and three supporting rod bodies 112, 114, 116 and a supporting rod body 118 are in The semicircular arc sides 138 opposite to the opening side are arranged in parallel at intervals. In addition, the first and second supporting rod bodies 112 and 114 are respectively located near the two ends of the semicircular arc side, as shown in FIG. 6. In one embodiment, the second supporting rod body 114 and the third supporting rod body 116 are separated by about 45 degrees; the first supporting rod body 112 and the supporting rod body 118 are separated by about 45 degrees; and the third supporting rod body 116 is separated from the supporting rod The bodies 118 are approximately 90 degrees apart, as shown schematically in FIGS. 3 and 6. Compared with a wafer boat with more supporting rods, the vertical wafer boat according to this creation can obtain the following advantageous effects by using three supporting rods and one supporting rod: the contact area with the wafer is less ; And it is more conducive to the balance support when the wafer is placed on the wafer boat.

By using the vertical wafer boat 106 with an inclined and rough supporting surface according to the present invention, the uniformity of the film formed by reaction on the wafer surface can be improved, and the undesirable particles on the wafer can be reduced. cut back. In a preferred embodiment, the angle between the inclined bearing surface of the groove and the horizontal plane is between 8° and 10°. In another preferred embodiment, the angle between the inclined bearing surface of the groove and the horizontal plane is about 10°. In addition, in a preferred embodiment, the surface roughness (Ra) of the inclined bearing surface of the trench is greater than 10 μm.

In some embodiments, the vertical wafer boat 106 can be made of quartz (for example, GE model, HSQ model quartz). However, it should be understood that the vertical wafer boat 106 may be made of any other suitable materials. In addition, in the vertical wafer boat 106, except for the first supporting rod 112, the second supporting rod 114, and the third supporting rod 116, the other parts can be processed to have a smooth surface and be sharp and/or sharp. Or sharp corners can be processed to make them round.

In some embodiments, the number of grooves provided on each of the first supporting rod 112, the second supporting rod 114, and the third supporting rod 116 may be tens to hundreds. In a better In the embodiment, the number of grooves provided on each of the first supporting rod 112, the second supporting rod 114, and the third supporting rod 116 is 170, and the inclined supporting surfaces of each groove are mutually connected. They are parallel and separated by a predetermined distance (for example, about 5.2 mm apart in one embodiment).

Compared with the conventional wafer boat of the vertical furnace tube (the bearing surface of the groove is a horizontal plane and the surface is smooth), this creation uses a vertical wafer boat with grooves with rough slopes, so the following beneficial effects can be obtained: When the reaction gas is transported into the vertical furnace tube 100 for diffusion reaction, since the vertical wafer boat according to the present invention has a small contact area with the wafer carried, the reaction gas can be uniformly and effectively in the crystal. The round surface reacts to improve the thickness uniformity of the deposited film; and it can also reduce the generation of particles on the wafer during the manufacturing process, thereby reducing wafer defects and effectively improving the yield.

Although the above embodiments have been described in detail for the purpose of clear understanding, it is obvious that certain changes and modifications can be implemented within the scope of the appended patent application. It should be noted that there are many alternative ways to implement the method and equipment of the embodiment of this case. Therefore, the embodiments of this case should be regarded as illustrative rather than restrictive, and the embodiments of this case should not be limited to the specific details set forth herein.

It should be understood that the structures and/or methods described herein are exemplary in nature, and these specific embodiments or examples should not be regarded as restrictive, as there may be various changes.

The subject of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various processes and structures disclosed herein, as well as other features, functions, actions, and/or characteristics, and any and all equivalents thereof.

106: vertical crystal boat

112: The first bearing rod

114: second bearing rod

116: The third bearing rod

118: Support rod

122: first board body

132: second board

Claims (7)

A vertical wafer boat for a vertical furnace tube, comprising: three supporting rods, each of which has a plurality of grooves, wherein each of the plurality of grooves has a supporting surface and a horizontal surface for supporting a wafer; The supporting rod body is used to strengthen the structural strength of the vertical wafer boat; the first plate body is located at the bottom of the vertical wafer boat and is connected to the lower end of each of the three supporting rod bodies and the supporting rod body ; And a second plate, located at the top of the vertical wafer boat, and connected to the upper end of each of the three supporting rods and the supporting rods, wherein the plurality of grooves on the three supporting rods The supporting surfaces are roughened and inclined with respect to the horizontal planes, and the vertical wafer boat has an opening side for wafers to enter and exit the vertical wafer boat, the three supporting rods and The supporting rods are arranged in parallel at intervals on the semicircular arc side opposite to the opening side, and the first and second supporting rod systems of the three supporting rods are respectively located on the two semicircular arc sides. Near the end. The vertical wafer boat for vertical furnace tubes according to claim 1, wherein the three supporting rod bodies, the supporting rod body, the first plate body, and the second plate system are made of quartz material. The vertical wafer boat for vertical furnace tube of claim 1, wherein the bearing surfaces of the plurality of grooves on the three bearing rod bodies have a surface roughness of Ra>10 μm. For example, the vertical wafer boat for vertical furnace tube of claim 1, wherein the angle between the bearing surfaces of the plurality of grooves on the three bearing rods and the horizontal planes is about 8°~10 ° within the range. For example, the vertical wafer boat for the vertical furnace tube of claim 4, wherein the angle between the bearing surfaces of the plurality of grooves on the three bearing rod bodies and the horizontal planes is about 10°. For example, the vertical wafer boat for the vertical furnace tube of claim 1, wherein the third supporting rod of the three supporting rods and the second supporting rod are separated by about 45° on the side of the semicircular arc, And the supporting rod body and the first bearing rod body are separated by about 45° on the side of the semicircular arc. A vertical furnace tube includes: an outer tube; an inner tube arranged inside the outer tube; a plurality of gas injectors, which extend from the outside of the outer tube to the inside of the inner tube, for connecting one or more The reaction gas is delivered to the inside of the vertical furnace tube; and the vertical wafer boat according to any one of Claims 1 to 6 is arranged inside the inner tube and used to carry wafers.

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