CN213026072U

CN213026072U - Crystal boat

Info

Publication number: CN213026072U
Application number: CN202022505172.8U
Authority: CN
Inventors: 李亮亮
Original assignee: Xian Eswin Silicon Wafer Technology Co Ltd; Xian Eswin Material Technology Co Ltd
Current assignee: Xian Eswin Silicon Wafer Technology Co Ltd; Xian Eswin Material Technology Co Ltd
Priority date: 2020-11-03
Filing date: 2020-11-03
Publication date: 2021-04-20
Anticipated expiration: 2030-11-03

Abstract

The utility model relates to a crystal boat, including the base with set up perpendicularly in support frame on the base, be provided with a plurality of bearing structure that are used for bearing the weight of the silicon chip along its extending direction interval on the support frame, bearing structure includes a plurality of bulges that are used for supporting in the edge of silicon chip, still includes a plurality of auxiliary supporting parts, every auxiliary supporting part and corresponding bearing structure cooperatees in order to support same silicon chip jointly, auxiliary supporting part can support in the center of silicon chip, auxiliary supporting part and every any among the bearing structure the bulge is kept away from the one end of support frame is connected, perhaps auxiliary supporting part connect in on the support frame.

Description

Crystal boat

Technical Field

The utility model relates to a silicon chip product preparation technical field especially relates to a wafer boat.

Background

In the growth process of the Czochralski (CZ) silicon single crystal, oxygen with certain concentration exists in the silicon single crystal due to the dissolution of a quartz crucible, the existence of oxygen impurities can not only greatly improve the mechanical strength of the silicon wafer, but also generate a large amount of oxygen precipitates, induced defects and other bulk defects (BMDs) in the silicon wafer body in the annealing process, thereby effectively absorbing metal impurities on the surface of the silicon wafer and improving the yield of integrated circuits. The intrinsic gettering process of the silicon wafer may be a high-low-high anneal, a low-high, or a low-high anneal, etc., which mainly depends on the process of heat treatment of the device, i.e., a process capable of forming a large amount of BMDs in the bulk of the silicon wafer and forming a Denuded Zone (DZ) on the surface of the silicon wafer while the device is being fabricated. And the silicon wafer is annealed at high temperature in hydrogen or argon gas, so that the external diffusion of oxygen in silicon is accelerated, a low-oxygen clean zone is formed on the surface of the silicon wafer, and the defects related to oxygen are greatly reduced.

In recent years, in order to further improve the utilization rate of silicon wafers, the diameter of the silicon wafers is getting larger, 300mm silicon wafers have already started to be produced on a large scale, and 450mm silicon wafers have come out and gradually come into the field of vision of people. The increase of the diameter of the silicon wafer greatly increases the preparation difficulty while increasing the cost for the manufacturing industry, such as the field of silicon wafer heat treatment. In the process of heat treatment of the silicon wafer, because extremely high cleanliness is required, a wafer boat serving as a bearing part of the silicon wafer is made of high-purity quartz, but in the related technology, the wafer boat only supports the edge of the silicon wafer, the gravity of the silicon wafer is increased along with the increase of the diameter of the silicon wafer, the silicon wafer can deform and warp under the action of the gravity, and the Young modulus of the silicon wafer is reduced and the deformation is increased at high temperature. In the heat treatment process of the silicon wafer, when the deformation exceeds the plastic deformation limit of the silicon wafer, the deformation is irreversible, the silicon wafer is easy to break, and silicon chips pollute other silicon wafers under the action of air flow, so that the quality loss is extremely high; and broken silicon chips fall down and are easy to damage equipment parts such as a wafer boat and the like, so that great cost loss is caused.

SUMMERY OF THE UTILITY MODEL

In order to solve the technical problem, the utility model provides a wafer boat solves the silicon chip size when great, bears on the wafer boat, because self action of gravity deformation problem broken even easily.

In order to achieve the above object, the embodiment of the present invention adopts the following technical solutions: the utility model provides a wafer boat, includes the base and set up perpendicularly in support frame on the base, be provided with a plurality of bearing structure that are used for bearing the weight of the silicon chip along its extending direction interval on the support frame, bearing structure includes a plurality of bulges that are used for supporting in the edge of silicon chip, still includes a plurality of auxiliary supporting parts, every auxiliary supporting part and corresponding bearing structure cooperatees in order to support same silicon chip jointly, auxiliary supporting part can support in the center of silicon chip, auxiliary supporting part and every any in the bearing structure the bulge is kept away from the one end of support frame is connected, perhaps auxiliary supporting part connect in on the support frame.

Optionally, the auxiliary supporting portion includes a supporting rod parallel to the base, a first end of the supporting rod is fixed to the supporting frame or fixed to the protruding portion, a second end of the supporting rod opposite to the first end is provided with a first supporting column perpendicular to the supporting rod, and the first supporting column can support the center of the silicon wafer.

Optionally, the width of the support bar perpendicular to the extension direction thereof is 10-15 mm.

Optionally, the diameter of the end face of the first support column is 2-5 mm.

Optionally, the cross section of the protruding portion in the direction perpendicular to the base is trapezoidal, the first surface of the protruding portion away from the base is an inclined surface, and a first distance between one end of the protruding portion close to the support frame and the base is greater than a second distance between one end of the protruding portion away from the support frame and the base.

Optionally, the inclination angle of the first face is 1-3 degrees.

Optionally, the support frame includes at least 3 second support columns perpendicular to the base, and a distance from each of the second support columns to the center of the base is the same.

Optionally, the minimum distance from each second supporting column to the center of the base is greater than the radius of the silicon wafer.

The utility model has the advantages that: the auxiliary supporting structure and the bearing structure are matched to support the same silicon wafer together, the bearing structure is supported at the edge of the silicon wafer, and the auxiliary supporting structure is supported at the center of the silicon wafer, so that the problem that the silicon wafer is deformed or even broken due to self gravity when the size of the silicon wafer is larger is solved.

Drawings

FIG. 1 is a diagram illustrating a stress state of a silicon wafer;

FIG. 2 is a first schematic view of a wafer boat according to an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a wafer boat according to an embodiment of the present invention;

FIG. 4 is a schematic view showing a silicon wafer loading state in the related art;

fig. 5 is a schematic view illustrating a silicon wafer carrying state according to an embodiment of the present invention.

Detailed Description

In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the drawings of the embodiments of the present invention are combined below to clearly and completely describe the technical solution of the embodiments of the present invention. It is to be understood that the embodiments described are only some of the embodiments of the present invention, and not all of them. All other embodiments, which can be derived from the description of the embodiments of the present invention by a person skilled in the art, are within the scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Referring to fig. 2 to 5, the present embodiment provides a boat, including a base 1 and a support frame 5 vertically disposed on the base 1, a plurality of bearing structures for bearing silicon wafers are disposed on the support frame 5 at intervals along an extending direction thereof, each bearing structure includes a plurality of protrusions 2 for supporting edges of the silicon wafers, and further includes a plurality of auxiliary support portions, each auxiliary support portion is matched with the corresponding bearing structure to jointly support a same silicon wafer, the auxiliary support portion can be supported at a center of the silicon wafer, and the auxiliary support portion is connected with one end of any one of the protrusions 2 of each bearing structure, which is far away from the support frame 5, or the auxiliary support portion is connected to the support frame 5.

Referring to fig. 1 and 4, the edge of the silicon wafer receives a supporting force Fn and receives its own weight G, and if the thickness of the silicon wafer is 787um and the diameter of the silicon wafer is 300mm, the mass M of the silicon wafer is 129G, the thickness of the silicon wafer is 787um and the diameter of the silicon wafer is 450mm, the mass M of the silicon wafer is 311G. The silicon wafer is idealized and is regarded as a two-dimensional object, and the deformation Y of the silicon wafer at room temperature is calculated by using a deflection formula 1-1 and is respectively as follows: y is₃₀₀＝0.249mm，Y₄₅₀0.6 mm. The Young's modulus of the single crystal silicon tends to decrease with the increase of the temperature, the deformation amount is further increased in the high-temperature process of the heat treatment, once the elastic limit of the silicon wafer is exceeded, the deformation of the silicon wafer cannot be recovered, the quality is deteriorated, and the deformation amount of the silicon wafer is accumulated under the high-temperature cycle action.

Wherein: p-load, L-span, E-Young's modulus, I-cross-sectional area, Y-deflection

Fig. 4 is a schematic view of a silicon wafer bearing state in the related art, where an edge of a silicon wafer 10 is stressed, and fig. 5 is a schematic view of a silicon wafer bearing state in an embodiment of the present invention, it can be seen that the silicon wafer 10 is not only supported by the edge but also supported by the center of the silicon wafer.

In this embodiment, exemplarily, the auxiliary supporting portion includes a supporting rod 3 parallel to the base 1, a first end of the supporting rod 3 is fixed on the supporting frame 5 or fixed on the protruding portion 2, a first supporting column 4 perpendicular to the supporting rod 3 is disposed at a second end of the supporting rod 3 opposite to the first end, and the first supporting column 4 can support the center of the silicon wafer. The existence of the silicon wafer center supporting point increases the stability of the silicon wafer, so that the deformation of the silicon wafer is extremely small, and the probability of deformation, bending or crushing of the silicon wafer is reduced.

In the present embodiment, the width of the support bar 3 perpendicular to its extension is, for example, 10-15 mm.

In the embodiment, the diameter of the end face of the first support column 4 is 2-5 mm. The silicon wafer is supported, deformation of the silicon wafer is prevented, and meanwhile, the phenomenon that the silicon wafer is polluted due to the fact that the contact area of the first support column 4 and the silicon wafer is too large is avoided.

In this embodiment, preferably, when a silicon wafer is loaded, the center point of the end surface of the first support column 4 coincides with the center point of the silicon wafer.

In this embodiment, for example, a cross section of the protruding portion 2 in a direction perpendicular to the base 1 is trapezoidal, a first surface of the protruding portion 2 away from the base 1 is an inclined surface, and a first distance between one end of the protruding portion 2 close to the supporting frame 5 and the base 1 is greater than a second distance between one end of the protruding portion 2 away from the supporting frame 5 and the base 1.

The inclined surface is arranged, so that when the silicon wafer is borne on the wafer boat, the contact between the silicon wafer and the protruding parts 2 is point contact, the contact area between the silicon wafer and the protruding parts 2 is reduced, and the pollution to the silicon wafer is reduced.

In this embodiment, the inclination angle of the first surface is 1 to 3 degrees, and in a specific embodiment, the inclination angle of the first surface is 2 degrees.

In this embodiment, the supporting frame 5 includes at least 3 second supporting columns perpendicular to the base 1, and a distance from each of the second supporting columns to a center of the base 1 is the same.

The connecting lines of the three second supporting columns form a part of a circular curve, and at this time, the auxiliary supporting structure is connected to a corresponding protrusion part 2.

In the present embodiment, for example, the minimum distance from each of the second supporting pillars to the center of the base 1 is greater than the radius of the silicon wafer.

The bearing space formed by the support frame 5 is larger than the area of the silicon wafer, and the silicon wafer bearing is facilitated.

In the embodiment, the difference between the diameter of the circular curve formed by the connection of the points of the three second supporting columns far away from the center point of the base 1 and the diameter of the silicon wafer is 20-30 mm.

In the present embodiment, the base 1, the supporting frame 5, the supporting structure and the auxiliary supporting structure are formed integrally, and are made of high-purity quartz material.

The above is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should be considered as the protection scope of the present invention.

Claims

1. The utility model provides a crystal boat, includes the base and set up perpendicularly in support frame on the base, be provided with a plurality of bearing structure that are used for bearing the weight of the silicon chip along its extending direction interval on the support frame, bearing structure includes a plurality of bulges that are used for supporting in the edge of silicon chip, its characterized in that still includes a plurality of auxiliary supporting parts, every auxiliary supporting part with correspond bearing structure cooperatees in order to support same silicon chip jointly, auxiliary supporting part can support in the center of silicon chip, auxiliary supporting part and every any in the bearing structure the bulge is kept away from the one end of support frame is connected, perhaps auxiliary supporting part connect in on the support frame.

2. The wafer boat according to claim 1, wherein the auxiliary supporting portion comprises a supporting rod parallel to the base, a first end of the supporting rod is fixed on the supporting frame or a protruding portion, a second end of the supporting rod opposite to the first end is provided with a first supporting pillar perpendicular to the supporting rod, and the first supporting pillar can support the center of the silicon wafer.

3. The wafer boat according to claim 2, wherein the support rods have a width perpendicular to the extension direction thereof of 10-15 mm.

4. The wafer boat according to claim 2, wherein the end surface diameter of the first support column is 2-5 mm.

5. The substrate boat of claim 2, wherein the cross-section of the protrusion in a direction perpendicular to the base is trapezoidal, the first surface of the protrusion away from the base is sloped, and a first distance between an end of the protrusion near the support frame and the base is greater than a second distance between an end of the protrusion away from the support frame and the base.

6. The wafer boat of claim 5, wherein the first face is inclined at an angle of 1-3 degrees.

7. The substrate boat of claim 2, wherein the support frame comprises at least 3 second support posts disposed perpendicular to the base, each of the second support posts being spaced apart from a center of the base by the same distance.

8. The substrate boat of claim 7, wherein the minimum distance from each of the second support posts to the center of the base is greater than the radius of a silicon wafer.