CN118007108A - A wafer carrying device for deposition reaction in a vertical furnace tube - Google Patents

Abstract

The present invention discloses a bearing device for a wafer deposition reaction in a vertical furnace tube, comprising a bearing frame and a multi-layered crystal placing space arranged on the bearing frame, wherein the bearing frame is provided with a plurality of supporting members for bearing wafers on the peripheral side of each crystal placing space to realize horizontal positioning and placement of the wafers, and the top surface of the supporting member is provided as a bearing surface for bearing the peripheral side of the wafer, the bearing surface is an uneven rough surface, and a suspended groove for suspending the peripheral edge of the wafer is formed between the bearing surface and the bearing frame. The bearing device for a wafer deposition reaction in a vertical furnace tube has the advantages of avoiding the wafer from being broken during the process of cooling from the reaction temperature to the room temperature, preventing the edge from being damaged when taking the wafer, and reducing the color difference of the back side of the wafer.

Description

Bearing device for deposition reaction of wafer in vertical furnace tube

Technical Field

The invention relates to the technical field of semiconductor manufacturing, in particular to a bearing device for a deposition reaction of a wafer in a vertical furnace tube.

Background

Polysilicon (POLY) deposition processes are classified into Undoped Polysilicon (UPOLY) deposition and doped polysilicon Deposition (DPOLY) processes. Doped polysilicon is used mainly as gate, fill and interconnect materials for MOS devices during semiconductor device fabrication, and undoped polysilicon is used mainly as mask, resistive material or as isolation material between different devices.

The typical reaction temperature of the process for doping the polysilicon is 520-580 ℃, and silane and phosphane are simultaneously introduced into a high-temperature furnace tube for reaction. Typical reaction temperature of undoped polysilicon is 600-650 ℃, and silane is directly introduced into a high-temperature furnace tube for reaction. The polysilicon film deposited by the method has the advantages of strong step coverage capability, good uniformity, high production efficiency, low manufacturing cost and the like.

Currently, most polysilicon deposition equipment is vertical furnace tube equipment. The wafer boat (process boat) is a carrier for carrying wafers into a furnace tube for processing, the existing wafer boat is shown in fig. 1, and generally comprises 4 support columns, wherein support members (support blocks shown in fig. 1 or clamping grooves shown in fig. 2 and 3) are arranged on the same horizontal plane of each support column to form a plurality of layers of support members, each layer of support members can horizontally hold a wafer, the surface of the support member contacted with the back of the wafer is smooth, and the roughness is smaller (less than 0.8 mu m); the contact surface between the wafer and the supporting member is basically well attached on the wafer boat, the amount of process gas entering the contact area between the wafer and the supporting member in the process is very small, the deposited crystalline silicon film layer is very thin, the edge position of the supporting member, which is contacted with the wafer, is in surface-to-surface contact, the contact area is large, and the polycrystalline silicon generated in the polycrystalline silicon deposition process is mainly concentrated in the long and narrow boundary area where the wafer and the supporting member are bordered.

In the actual production process, if the thickness of the deposited polysilicon film per furnace required by the process exceedsWhen the wafer boat carries wafers and carries out deposition reaction in the furnace tube, the grown polycrystalline silicon is basically and completely connected with the wafer boat, the supporting member with smooth surface and the wafer are always adhered, and the wafer (generally referred to as silicon wafer) is adhered to the supporting member, so that the wafer cannot be broken due to adhesion resistance easily caused in the process that the wafer falls to room temperature from the reaction temperature in a short time along with the wafer boat, and the wafer edge is easily damaged when the wafer is taken because the wafer is adhered to the supporting member of the wafer boat, as shown in fig. 4. In addition, during the deposition process, there is a color difference between the back of the wafer where the wafer contacts the support member and the back of the wafer where the wafer does not contact, as shown in fig. 5.

Disclosure of Invention

The invention aims to solve the technical problem of overcoming the defects in the prior art, and provides the bearing device for reducing the wafer adhesion, avoiding the wafer from being broken in the process of reducing the reaction temperature to the room temperature, preventing the edge from being damaged when the wafer is taken, and reducing the deposition reaction of the wafer with chromatic aberration on the back surface of the wafer in the vertical furnace tube.

In order to solve the technical problems, the invention adopts the following technical scheme:

The utility model provides a bearing device of wafer deposition reaction in vertical boiler tube, includes the carrier and locates the crystal space of putting of multilayer arrangement on the carrier, the carrier all is equipped with a plurality of backing members that are used for bearing the wafer in order to realize locating the wafer level in the week side of each crystal space, the top surface of backing member is established to the loading surface that is used for bearing the wafer circumference side, the loading surface is the rough surface of roughness, form the suspension groove that is used for making the wafer circumference edge unsettled between loading surface and the carrier.

As a further improvement of the above technical scheme:

the roughness of the bearing surface is greater than 3 mu m.

The supporting member comprises a supporting part and a bearing part, wherein the supporting part is obliquely fixed on the bearing frame, one end of the bearing part is fixed at the top end of the supporting part, the other end of the bearing part faces the center of the crystal placing space, the bearing surface is formed on the top surface of the bearing part, and the suspension groove is formed above the supporting part.

The length of the supporting part in the radial direction of the crystal placing space is L1, and the length of the bearing part in the radial direction of the crystal placing space is L2, so that the condition that L2 is more than L1 is satisfied.

The L1 is 2-4mm, and the L2 is 6-8mm.

The thickness H2 of the bearing part is 2-3.5mm, the width W2 is 15-20mm, the thickness H1 of the supporting part is 1.8-3.2mm, the width W1 satisfies w1=w2, and the thickness of the connecting part of the bearing part and the supporting part is smaller than or equal to the thickness of the bearing part.

The inclination angle alpha of the upper surface of the supporting part is 5-30 degrees.

The edge of the bearing surface facing the center of the crystal placing space is arc-shaped.

The bearing frame comprises a plurality of support columns, the support columns are arranged at intervals around the design center, the crystal placing space is formed between the support columns, the support members are respectively fixed on the inner sides of the support columns, the bearing frame forms an inlet and an outlet for a wafer to enter and exit at one side of each crystal placing space, and the suspension groove is formed between the bearing surface and the support columns.

The bearing frame and the supporting member are made of quartz materials.

Compared with the prior art, the invention has the advantages that:

When the bearing device for the deposition reaction of the wafer in the vertical furnace tube is used, the wafer is placed on the bearing surface of each supporting member in the wafer placing space, the wafer is in point-to-surface contact and/or line-to-surface contact with the bearing surface with smaller contact area, the contact effective area of the wafer and the bearing surface is greatly reduced, and even if the growth reaction occurs between the wafer and the bearing surface in the deposition process, the effective contact area of the growing polysilicon film is reduced, so that the wafer is not easy to adhere to the bearing surface after the wafer process is finished, the adhesion of the wafer and the supporting members is reduced, and the wafer is prevented from being broken in the process of reducing the reaction temperature to room temperature. And the peripheral edge of the wafer is suspended on the suspension groove and cannot be contacted with the bearing surface, so that the wafer edge is prevented from being damaged when the wafer is taken, the possibility of wafer edge breakage is reduced, and the integrity of the wafer is ensured. In addition, the wafer and the supporting member are contacted through the rough surface with convex and concave, so that point-surface contact and/or line-surface contact are formed, and the chromatic aberration existing on the back of the wafer is reduced due to the small contact surface. Thereby improving the value and the production benefit of the wafer.

Drawings

FIG. 1 is a schematic diagram of a front view of a conventional wafer boat.

FIG. 2 is a schematic diagram of a slot of a conventional wafer boat.

FIG. 3 is a schematic top view of a conventional wafer boat.

Fig. 4 is a schematic diagram of damage to the wafer edge.

Fig. 5 is a color difference plot of the back side of the wafer.

FIG. 6 is a schematic diagram of a front view of a wafer deposition reaction carrier in a vertical furnace.

Fig. 7 is an enlarged schematic view of the structure at a of fig. 6.

FIG. 8 is a schematic top view of a carrier device for wafer deposition reaction in a vertical furnace according to the present invention.

The reference numerals in the drawings denote:

1. A carrier; 11. a support column; 2. a crystal placing space; 3. a support member; 31. a support part; 32. a carrying part; 4. a wafer; 5. a bearing surface; 6. a suspension groove; 7. and (5) an inlet and an outlet.

Detailed Description

The invention is described in further detail below with reference to the drawings and specific examples of the specification.

In the description of the present application, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present application and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

Fig. 6 to 8 show an embodiment of a carrying device for depositing and reacting a wafer in a vertical furnace tube according to the present invention, where the carrying device for depositing and reacting a wafer in a vertical furnace tube includes a carrying frame 1 and a plurality of placing spaces 2 disposed on the carrying frame 1 in multiple layers, the carrying frame 1 is provided with a plurality of supporting members 3 for carrying the wafer 4 on the peripheral side of each placing space 2 to horizontally position the wafer 4, the top surface of the supporting members 3 is a carrying surface 5 for carrying the peripheral edge of the wafer 4, the carrying surface 5 is a rough surface with uneven surface, and a suspending groove 6 for suspending the peripheral side of the wafer 4 is formed between the carrying surface 5 and the carrying frame 1.

When the wafer 4 is used, the wafer 4 is placed on the bearing surface 5 of each supporting member 3 in the wafer placing space 2, the wafer 4 is in point-to-surface contact and/or line-to-surface contact with the bearing surface 5 with smaller contact area, the contact effective area of the wafer 4 and the bearing surface 5 is greatly reduced, and even if the wafer 4 and the bearing surface 5 undergo a growth reaction in the deposition process, the wafer 4 is not easy to adhere to the bearing surface 5 after the process of growing the polycrystalline silicon film is completed, so that the adhesion of the wafer 4 and the supporting members 3 is reduced, and the wafer 4 is prevented from being broken in the process of reducing the reaction temperature to room temperature. In addition, the periphery of the wafer 4 is suspended on the suspension groove 6 and cannot be contacted with the bearing surface 5, so that the edge of the wafer 4 is prevented from being damaged when the wafer 4 is taken, the possibility of edge breakage of the wafer 4 is reduced, and the integrity of the wafer 4 is ensured. In addition, the wafer 4 and the supporting member 3 are contacted through the rough surface with convex and concave, so that point-surface contact and/or line-surface contact are formed, and the chromatic aberration existing on the back surface of the wafer 4 is reduced due to the small contact surface. Thereby improving the value and production efficiency of the wafer 4.

Further, in the present embodiment, the roughness of the bearing surface 5 is greater than 3 μm. In the range that the roughness of the bearing surface 5 is more than 3 mu m, the wafer 4 and the bearing surface 5 can have good anti-adhesion effect.

Further, in the present embodiment, the supporting member 3 includes a supporting portion 31 and a bearing portion 32, the supporting portion 31 is obliquely fixed on the carrier 1, one end of the bearing portion 32 is fixed at the top end of the supporting portion 31, the other end faces the center of the crystal placing space 2, the bearing surface 5 is formed on the top surface of the bearing portion 32, and the suspending groove 6 is formed above the supporting portion 31. The whole structure is simple, and the processing is convenient. The supporting part 31 is obliquely arranged, so that a suspension groove 6 is formed above the supporting part 31, one end of the bearing part 32 is fixed at the top end of the supporting part 31, and the other end faces the center of the wafer placing space 2, thereby meeting the horizontal placing requirement and the peripheral suspension requirement of the wafer 4.

Further, in the present embodiment, as shown in fig. 7, the length of the supporting portion 31 in the radial direction of the seeding space 2 is L1, and the length of the carrying portion 32 in the radial direction of the seeding space 2 is L2, so that L2 > L1 is satisfied. Not only meets the requirement of supporting strength, but also meets the requirement of stable placement.

Further, in this embodiment, L1 is 2-4mm and L2 is 6-8mm.

Further, in the present embodiment, as shown in fig. 7 and 8, the thickness (maximum thickness) H2 of the bearing portion 32 is 2-3.5mm, the width W2 is 15-20mm, the thickness H1 of the supporting portion 31 is 1.8-3.2mm, the width W1 satisfies w1=w2, and the thickness of the connection portion between the bearing portion 32 and the supporting portion 31 is less than or equal to the thickness of the bearing portion 32.

Further, in the present embodiment, as shown in fig. 7, the inclination angle α of the upper surface of the supporting portion 31 is 5 ° -30 °.

Further, in this embodiment, the edge of the carrying surface 5 facing the center of the seeding space 2 is arc-shaped.

Further, in this embodiment, the carrier 1 includes a plurality of support columns 11, each support column 11 is arranged around the design center at intervals, the crystal placing space 2 is formed between each support column 11, each support member 3 is respectively fixed on the inner side of each support column 11, the carrier 1 forms an inlet and outlet 7 for the wafer 4 to enter and exit at one side of each crystal placing space 2, and the suspension groove 6 is formed between the carrying surface 5 and the support column 11. The outer diameter of the dicing space 2 is larger than the outer diameter of the wafer 4.

Preferably, the support columns 11 are uniformly spaced around the design center, and the winding path of each support column 11 is semicircular. The bearing surfaces 5 in the crystal placing spaces 2 have the same height from the ground, so that the wafer 4 can be horizontally placed.

Further, in this embodiment, the carrier 1 and the supporting member 3 are both made of quartz. The inlet and outlet 7 of each crystal placing space 2 is positioned on the same side of the bearing frame 1, so that the wafers 4 can be conveniently taken and placed. The height of the relief space 2 is greater than the thickness of the wafer 4.

When the thickness of the deposited polysilicon film increases above a certain value, the carrier surface 5 needs to be cleaned (pickled) by using a mixed solution of hydrofluoric acid, nitric acid and water in a certain proportion, and each pickling will corrode and destroy the carrier surface 5 to a certain extent (form a slightly rugged pothole-like surface), thereby increasing the roughness of the carrier surface 5. At this time, when the polysilicon deposition process is performed again, the line-surface contact between the wafer 4 and the carrying surface 5 gradually changes from the previous line-surface contact to the point-surface contact. As the number of pickling increases, the roughness of the support surface 5 increases, and the space for the process gas to enter the contact area of the support surface 5 with the wafer 4 increases, which will make it less likely that the wafer 4 will adhere to the support surface 5 after the support surface 5 has been pickled a number of times, even when a thick film is redeposited each time. At this time, the thickness of the film grown on the back surface of the wafer 4 is more uniform; the color of the contact area of the wafer 4 and the bearing surface 5 and the color of the non-contact area are not obviously abnormal.

The bearing device for the deposition reaction of the wafer in the vertical furnace tube has simple structure and low processing and hardware cost; the consistency of the film on the back surface of the wafer during the deposition of the polysilicon can be effectively improved, thereby improving the yield of products; the contact area of the wafer 4 and the supporting member 3 can be effectively reduced, and the adhesion of the wafer 4 and the supporting member 3 is reduced, so that the possibility of edge breakage of the wafer 4 is reduced, the integrity of the wafer 4 is ensured, and the value and the production benefit of the wafer 4 are improved.

While the invention has been described with reference to preferred embodiments, it is not intended to be limiting. Many possible variations and modifications of the disclosed technology can be made by anyone skilled in the art, or equivalent embodiments with equivalent variations can be made, without departing from the scope of the invention. Therefore, any simple modification, equivalent variation and modification of the above embodiments according to the technical substance of the present invention shall fall within the scope of the technical solution of the present invention.

Claims (10)

1. The utility model provides a bear device of wafer deposition reaction in vertical boiler tube, includes carrier (1) and locates on carrier (1) multilayer arrangement put brilliant space (2), carrier (1) all is equipped with a plurality of backing members (3) that are used for bearing wafer (4) in order to realize locating the wafer (4) level in the week side of putting brilliant space (2), its characterized in that: the top surface of the supporting member (3) is a bearing surface (5) for bearing the periphery of the wafer (4), the bearing surface (5) is a rough surface with convex and concave, and a suspension groove (6) for suspending the periphery of the wafer (4) is formed between the bearing surface (5) and the bearing frame (1).

2. The wafer deposition reaction load bearing apparatus of claim 1 wherein: the roughness of the bearing surface (5) is greater than 3 μm.

3. The wafer deposition reaction load bearing apparatus of claim 1 wherein: the supporting member (3) comprises a supporting part (31) and a bearing part (32), the supporting part (31) is obliquely fixed on the bearing frame (1), one end of the bearing part (32) is fixed at the top end of the supporting part (31) and the other end of the bearing part faces the center of the crystal placing space (2), the bearing surface (5) is formed on the top surface of the bearing part (32), and the suspension groove (6) is formed above the supporting part (31).

4. The wafer deposition reaction load bearing apparatus in a vertical furnace of claim 3, wherein: the length of the supporting part (31) in the radial direction of the crystal placing space (2) is L1, and the length of the bearing part (32) in the radial direction of the crystal placing space (2) is L2, so that the condition that L2 is more than L1 is satisfied.

5. The carrier for a deposition reaction of a wafer in a vertical furnace of claim 4, wherein: the L1 is 2-4mm, and the L2 is 6-8mm.

6. The apparatus of claim 5 wherein the wafer is deposited in a vertical furnace wherein: the thickness H2 of the bearing part (32) is 2-3.5mm, the width W2 is 15-20mm, the thickness H1 of the supporting part (31) is 1.8-3.2mm, the width W1 meets W1=W2, and the thickness of the connecting part of the bearing part (32) and the supporting part (31) is smaller than or equal to the thickness of the bearing part (32).

7. The wafer deposition reaction load bearing apparatus in a vertical furnace of claim 3, wherein: the inclination angle alpha of the upper surface of the supporting part (31) is 5-30 degrees.

8. The wafer carrier of any one of claims 1 to 7 for deposition reactions in a vertical furnace, wherein: the edge of the bearing surface (5) facing the center of the crystal placing space (2) is arc-shaped.

9. The wafer carrier of any one of claims 1 to 7 for deposition reactions in a vertical furnace, wherein: the bearing frame (1) comprises a plurality of support columns (11), the support columns (11) are arranged at intervals around the design center, the crystal placing space (2) is formed between the support columns (11), the support members (3) are respectively fixed on the inner sides of the support columns (11), the bearing frame (1) forms an inlet and outlet (7) for a wafer (4) to enter and exit at one side of the crystal placing space (2), and the suspension groove (6) is formed between the bearing surface (5) and the support columns (11).

10. The wafer carrier of any one of claims 1 to 7 for deposition reactions in a vertical furnace, wherein: the bearing frame (1) and the supporting member (3) are made of quartz materials.