CN216864307U

CN216864307U - Locking ring and physical vapor deposition equipment

Info

Publication number: CN216864307U
Application number: CN202220405508.XU
Authority: CN
Inventors: 荣海洋
Original assignee: SHANGHAI ADVANCED SEMICONDUCTO
Current assignee: SHANGHAI ADVANCED SEMICONDUCTO
Priority date: 2022-02-24
Filing date: 2022-02-24
Publication date: 2022-07-01
Anticipated expiration: 2032-02-24

Abstract

The utility model provides a locking ring and physical vapor deposition equipment, wherein the locking ring comprises a plurality of coaxially arranged annular grooves and an extension ring, the plurality of coaxially arranged annular grooves are sequentially abutted from inside to outside, the outer surface of the groove wall of the innermost annular groove close to the circle center is provided with a plurality of side wall salient points, the extension ring is connected with the circumferential edge of the bottom wall of the innermost annular groove and extends towards the axis direction along the bottom wall of the annular groove, the upper surface of the extension ring is provided with a plurality of pressure points, and the side wall salient points are positioned between two adjacent pressure points. According to the utility model, the side wall salient points and the pressure points are arranged in a staggered manner, and the side wall salient points, the pressure points and the wafer positioning notches of the wafer are also staggered, so that when the wafer is deformed, the deformation force is released towards one direction at the contact points of the edge of the wafer and the locking ring, the phenomenon that the edge of the wafer is subjected to corner defect due to the combined action of two mutually close stress points is prevented, and the probability of the corner defect of the wafer is reduced under the condition that the technological parameters of equipment are not influenced.

Description

Locking ring and physical vapor deposition equipment

Technical Field

The utility model belongs to the technical field of semiconductors, and relates to a locking ring and physical vapor deposition equipment.

Background

A mainstream Physical Vapor Deposition (PVD) device is mainly used for a 0.18-0.5 micron integrated circuit manufacturing process, and is generally used for processes of depositing aluminum copper (AlCu), aluminum silicon copper (AlSiCu), titanium (Ti), titanium nitride (TiN), titanium (IMP Ti) deposited by a dissociated metal plasma method, titanium (SIP Ti) plated by a sputtered ion and the like.

In the process of physical vapor deposition equipment, the heavily-doped substrate deep groove wafer is easy to bend and displace greatly in the thick aluminum copper process due to the deep groove, so that the contact part of the edge of the wafer and the pressure point of the locking ring is influenced, the edge notch of the wafer is caused, particularly the positioning notch of the edge of the wafer is easy to cause the notch due to the special structure of the wafer and the contact part touches the pressure point or the positioning convex point of the locking ring. As shown in fig. 1, which is a schematic structural diagram of a locking ring, wherein the locking ring includes an annular groove 01, sidewall bumps 011, a positioning opening 012, a ground port 013, an extension ring 02, pressure points 021 and an extension portion 022, in a PVD process, temperature changes cause a wafer to bend and displace, so that an edge of the wafer contacts a side surface of the locking ring and is pressed by the pressure points on the front surface of the locking ring, and then a notch is generated, which leads to alignment alarm of subsequent photolithography equipment and finally leads to wafer scrap. At present, the method of adjusting the position of the wafer in the process cavity is generally adopted to reduce the corner defect phenomenon, the method is fussy to operate, and the effect of improving the corner defect of the wafer is not obvious.

Therefore, a lock ring which has a significant effect of improving the corner defect of the wafer in the PVD process and does not affect the process parameters of the chamber is urgently needed.

SUMMERY OF THE UTILITY MODEL

In view of the above drawbacks of the prior art, an object of the present invention is to provide a lock ring and a pvd apparatus, which are used to solve the problem of high wafer corner defect rate during the process of the pvd apparatus in the prior art.

To achieve the above and other related objects, the present invention provides a locking ring, comprising:

the annular grooves are coaxially arranged and are sequentially abutted from inside to outside, and a plurality of side wall salient points are arranged on the outer surface of the groove wall of the innermost annular groove close to the circle center;

the extension ring is connected with the circumferential edge of the bottom wall of the innermost annular groove and extends towards the axis direction along the bottom wall of the annular groove, a plurality of pressure points are arranged on the front face of the extension ring, and the side wall salient points are positioned between two adjacent pressure points.

Optionally, adjacent sides between two adjacent annular grooves share one groove sidewall.

Optionally, at least two of the annular grooves have non-common sidewalls of different heights.

Optionally, when a wafer positioning notch is formed in the edge of the wafer pressed by the locking ring, the position of the wafer positioning notch is staggered with the positions of the side wall salient point and the pressing point respectively.

Optionally, the sidewall tabs are in contact with a front face surface of the extension ring.

Optionally, the pressure point is located on the front surface of the extension ring between two adjacent sidewall bumps.

Optionally, the inner side of the extension ring is further provided with at least one extension part connected with the extension ring.

Optionally, at least one positioning opening is provided on a groove wall of the innermost annular groove close to the axial center.

Optionally, at least one ground port is further provided at the groove wall edge of the annular groove.

A physical vapor deposition device comprises the locking ring.

As described above, the locking ring and the pvd apparatus of the present invention, by redesigning the structure of the locking ring, stagger the pressure points disposed on the front surface of the extension ring and the sidewall protrusions disposed outside the trench wall of the innermost annular trench close to the axis, and stagger the positions of the wafer positioning notches with the sidewall protrusions and the pressure points, so that the contact points between the wafer edge and the pressure points and the sidewall protrusions are dispersed, and the sidewall protrusions and the pressure points cannot act on the wafer positioning notches, thereby dispersing the deformation force generated by the deformation of the wafer due to the temperature change to the edge of the wafer during the thin film deposition process, and releasing the deformation force in one direction, preventing the two stress points on the wafer edge from being close to act together to cause the wafer to generate a corner defect, under the condition of not influencing the technological parameters of the equipment, the yield of the deposition process is improved, the maintenance frequency of the equipment is reduced, the production cost is reduced, and the method has high industrial utilization value.

Drawings

Fig. 1 is a schematic structural view of a locking ring.

Fig. 2 is a schematic plan view of the locking ring of the present invention.

Fig. 3 is a schematic structural view of a positioning opening of the locking ring of the present invention.

Fig. 4 is a schematic cross-sectional view illustrating a wafer pressed by the clamp ring according to the present invention.

FIG. 5 is a statistical chart of the production yield of PVD equipment before and after the use of the clamp ring of the utility model.

Description of the element reference numerals

01 annular groove

011 side wall salient point

012 positioning opening

013 ground port

02 extension ring

021 pressure point

022 extension

1 annular groove

11 side wall salient point

12 positioning opening

13 ground port

2 extension ring

21 pressure point

22 extension part

Detailed Description

The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The utility model is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention.

Please refer to fig. 2 to 5. It should be noted that the drawings provided in the present embodiment are only for illustrating the basic idea of the present invention, and the components related to the present invention are only shown in the drawings rather than drawn according to the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.

Example one

The embodiment provides a locking ring, as shown in fig. 2, does the planar structure schematic diagram of locking ring, including a plurality of coaxial setting's annular slot 1 and extend ring 2, wherein, a plurality of coaxial annular slot 1 borders on from inside to outside in proper order, and the innermost annular slot 1 is equipped with a plurality of lateral wall bumps 11 near the ditch groove wall surface of the centre of a circle, extend ring 2 and the innermost the diapire circumferential edge of annular slot 1 is connected and is followed annular slot 1's diapire extends to axle center direction, the upper surface of extending ring 2 is equipped with a plurality of pressure points 21, just lateral wall bump 11 is located adjacent two between the pressure point 21.

As an example, adjacent sides between adjacent two of the annular grooves 1 share one groove sidewall.

Specifically, the number of the annular grooves 1 may be set according to practical conditions, and is not limited herein. In this embodiment, three annular grooves 1 are selected to be adjacent to each other, so that the wafer is prevented from being damaged due to the overweight of the locking ring, and the wafer can be pressed by the locking ring.

Specifically, under the condition that the wafer can be pressed by the locking ring and is not damaged, the groove width of each annular groove 1, the groove depth of each annular groove 1 and the thickness of the groove side wall of each annular groove 1 can be set according to actual conditions, and no limitation is made here.

Specifically, the material of the annular groove 1 includes metal or other suitable materials.

As an example, at least two of said annular grooves 1 have non-common sidewalls with different heights. In this embodiment, the height of the sidewall of the outermost annular groove 1, which is far away from the axis, is higher to protect the locking ring.

As an example, the bottom surfaces of the annular grooves 1 are on the same plane.

Specifically, the sidewall protrusions 11 are used to urge the wafer to approach the axis of the locking ring, and simultaneously leave a gap between the wafer and the sidewall of the innermost annular groove 1 near the axis, so as to prevent the wafer from adhering to the sidewall of the innermost annular groove 1 near the axis during a deposition process.

Specifically, the material of the sidewall bump 11 includes metal or other suitable materials. In this embodiment, the material of the sidewall bump 11 is the same as that of the annular groove 1.

Specifically, the material of the extension ring 2 includes metal or other suitable materials. In this embodiment, the extension ring 2 and the annular groove 1 are made of the same material.

Specifically, the diameter of the inner circle of the extension ring 2 is smaller than that of the wafer, so that the locking ring clamps the wafer by using the extension ring 2.

Specifically, the pressure point 21 protrudes from the surface of the front surface of the extension ring 2, so that when the wafer is pressed by the locking ring, a gap is formed between the pressure point and the wafer while the wafer is pressed, deposited particles can enter the gap, and the rest of the edge of the wafer except for the contact position of the pressure point 21 and the wafer can be deposited with a film.

Illustratively, the sidewall bumps 11 contact the front surface of the extension ring 2 to reduce the contact of the edge of the wafer with the trench sidewall of the innermost annular trench 1 when the wafer is compressed.

Specifically, under the condition that the wafer is enabled to approach the axis of the shrink ring and no sticking occurs during the PVC process, the number of the side wall bumps 11 may be set according to actual conditions, which is not limited herein, and in this embodiment, the number of the side wall bumps 11 is 6.

As an example, the pressure point 21 is located on the front surface of the extension ring 2 between two adjacent sidewall bumps 11, so that the pressure point 21 and the sidewall bump 11 are staggered from each other to act on the wafer.

Specifically, under the condition that the wafer is ensured to be pressed by the locking ring, the number of the pressure points 21 may be selected according to actual conditions, and may be the same as or different from the number of the sidewall bumps 11, for example.

Specifically, the staggered angle between the pressure points 21 and the side wall salient points 11 may be set according to actual conditions, preferably, the number of the pressure points 21 is the same as that of the side wall salient points 11, and the pressure points 21 are located on the front surface of the extension ring 2 corresponding to the arc midpoint between the two side wall salient points 11. In this embodiment, the number of the pressure points 21 is the same as that of the side wall salient points 11, and is 6, and an included angle between the pressure points 21 and the side wall salient points 11 is 30 °.

As an example, when a wafer positioning notch is formed in the edge of the wafer pressed by the locking ring, the position of the wafer positioning notch is staggered with the positions of the sidewall bumps 11 and the pressure points 21, respectively.

Specifically, since the wafer positioning notch is more easily damaged, when the locking ring is pressed onto the wafer, the position of the wafer positioning notch is staggered with the side wall salient point 11 and the pressure point 21 respectively to prevent the wafer from deforming, and the wafer positioning notch is damaged by the side wall salient point 11 and the pressure point 21. Preferably, the included angle between the wafer positioning notch and the pressing point 21 is 10 °. In this embodiment, the wafer positioning notch is 10 ° staggered from the pressure point 21.

Specifically, the material of the pressure point 21 includes metal or other suitable materials, and in this embodiment, the material of the pressure point 21 is the same as the material of the annular groove 1.

As an example, the inner side of the extension ring 2 is further provided with at least one extension 22 connected with the extension ring 2.

Specifically, the extension portion 22 is used for enabling the wafer to be flatly pressed under the locking ring, so as to prevent the wafer from being greatly warped.

Specifically, the number, size and shape of the extending portions 22 can be set according to practical situations, and are not limited herein. In this embodiment, 2 oppositely arranged extensions 22 are disposed on the edge of the extension ring.

Specifically, the material of the extension portion 22 includes metal or other suitable materials, and in this embodiment, the material of the extension portion 22 is the same as the material of the extension ring 2.

Specifically, when the clamping ring is pressed against the wafer, a gap exists between the extension ring 2 and the wafer to prevent the extension portion 22 from obstructing deposition of material on the upper surface of the wafer.

As an example, at least one positioning opening 12 is provided on the groove wall of the innermost annular groove 1 near the axial center.

Specifically, the positioning opening 12 is used for fixing the locking ring to prevent the locking ring from sliding and damaging the wafer.

Specifically, as shown in fig. 3, the number and size of the positioning openings 12 and the depth of the positioning openings 12 may be set according to actual situations, which is a schematic structural view of the positioning openings 12. In this embodiment, 4 positioning openings 12 are disposed on the trench wall of the innermost annular trench 1 near the axis, and the bottom surface of the positioning openings 12 is lower than the bottom surface of the inner wall of the annular trench 1, so as to adapt to a clamping structure of a mesa (not shown) for carrying the wafer, and the positioning openings 12 and the clamping structure are tightly nested together.

Specifically, the side wall of the groove close to the axis of the innermost annular groove 1 is tightly nested on the side wall of the mesa for bearing the wafer.

As an example, the groove wall edge of the annular groove 1 is further provided with at least one ground port 13 to prevent the electric charge from accumulating on the locking ring during operation.

Specifically, the number and the position of the ground ports 13 can be set according to actual conditions without interfering with the operation of the locking ring. In this embodiment, two of the ground ports are oppositely disposed on the groove wall of the outermost annular groove 1 close to the axis, and one of the ground ports 13 may be selected to be grounded during operation, so as to release the charges accumulated on the tightening ring during operation.

Specifically, a plurality of coaxially arranged annular grooves 1 and extension rings 2 can be simultaneously manufactured. In this embodiment, a metal cylinder with a suitable height is adopted, a plurality of annular grooves 1 are formed on the cylinder, which are adjacent to each other from outside to inside, and a groove wall and the extension ring 2 are formed on one side of the innermost annular groove 1, which is close to the axis.

Specifically, as shown in fig. 4, a schematic cross-sectional structure diagram of the locking ring pressing the wafer is shown, when a deposition process is performed, the wafer warps due to temperature changes, the side wall bumps 11 and the pressure points 21 are arranged, and positions of the wafer positioning notches on the wafer are staggered with the side wall bumps 11 and the pressure points 21, so that stress on the edge of the wafer is dispersed to each contact point, deformation force is released in one direction, the two stress points close to each other are prevented from acting on the edge of the wafer together, the probability of corner missing of the edge of the wafer is reduced, and the yield of the deposition process is improved.

In the locking ring of the embodiment, the plurality of side wall salient points 11 are arranged on the inner wall of the groove, close to the axis, of the annular groove 1 which is positioned at the innermost side, so that the wafer is close to the axis, and the plurality of pressure points 21 are arranged on the front surface of the extension ring 2, so that the shielded area of the wafer during deposition is reduced while the wafer is guaranteed to be pressed, and the wafer is prevented from being adhered to the extension ring 2 during deposition; in addition, the side wall salient points 11 and the pressure points 21 are arranged in a staggered mode, and the positions of the wafer positioning notches on the wafer are respectively staggered with the side wall salient points 11 and the pressure points 21, so that when the wafer warps, larger distances are staggered between the edge stress points of the wafer and between the stress points and the wafer positioning notches, deformation force is released in one direction, the two stress points which are close to each other are prevented from acting on the edge of the wafer together, the probability of corner defect of the wafer is reduced under the condition that the technological parameters of equipment are not influenced, and the yield of a deposition process is improved.

Example two

The embodiment provides a physical vapor deposition device, which comprises the locking ring in the first embodiment.

Specifically, the physical vapor deposition apparatus may be used to deposit aluminum copper (AlCu), aluminum silicon copper (AlSiCu), titanium (Ti), titanium nitride (TiN), or other suitable materials.

Specifically, before a film is deposited on a wafer, the wafer is placed on a table top of the pvd equipment for supporting the wafer, a positioning opening of the clamp ring in the first embodiment is aligned with a clamping structure on the table top, the clamp ring is pressed downward to compress the wafer, and a ground port of the clamp ring is grounded, so that the film is deposited.

Specifically, as shown in fig. 5, in order to obtain a statistical chart of yield before and after deposition by using the locking ring in the first embodiment, after a film is deposited by using the locking ring in the first embodiment in the ninth month, the corner defect rate of the wafer is reduced from 0.23% to 0.03%, so that the yield is improved, and the cost is reduced.

Specifically, the locking ring adopted in the first embodiment for deposition does not affect the process parameters of the deposition cavity, so that the equipment maintenance frequency is reduced, the equipment utilization rate is improved, and the equipment maintenance cost is reduced.

The physical vapor deposition equipment of the embodiment improves the yield of the film deposition process by adopting the locking ring in the first embodiment, reduces the equipment maintenance frequency, improves the utilization rate of the equipment and reduces the cost.

In summary, the locking ring and the pvd apparatus of the present invention are configured such that the plurality of pressure points disposed on the extension ring and the plurality of sidewall protrusions disposed outside the trench wall of the innermost annular trench close to the axis are staggered, so that in the process of depositing the thin film, the wafer warpage caused by the temperature change causes a large distance between the edge stress points of the wafer and between the stress points and the wafer positioning notches, and further the generated deformation force is released to one direction at the contact points of the wafer edge and the locking ring, thereby preventing the wafer corner defect caused by the edge of the wafer acted by two stress points close to each other, and reducing the probability of the wafer corner defect without affecting the process parameters of the apparatus, improving the yield of the deposition process, reducing the maintenance frequency of the apparatus, and reducing the cost.

The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the utility model. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.

Claims

1. A locking ring, comprising:

the annular grooves are coaxially arranged and are sequentially adjoined from inside to outside, and a plurality of side wall salient points are arranged on the outer surface of the groove wall of the innermost annular groove close to the circle center;

the extension ring is connected with the circumferential edge of the bottom wall of the innermost annular groove and extends towards the axis direction along the bottom wall of the annular groove, a plurality of pressure points are arranged on the front face of the extension ring, and the side wall salient points are located between every two adjacent pressure points.

2. The clamp ring of claim 1, wherein: the facing sides of two adjacent annular grooves share a groove side wall.

3. The clamp ring of claim 2, wherein: at least two of the annular grooves have non-common sidewalls of different heights.

4. The clamp ring of claim 1, wherein: when the edge of the wafer pressed by the locking ring is provided with a wafer positioning notch, the position of the wafer positioning notch is staggered with the positions of the side wall salient point and the pressure point respectively.

5. The clamp ring of claim 1, wherein: the sidewall tabs are in contact with a front surface of the extension ring.

6. The clamp ring of claim 1, wherein: the pressure points are located on the front surface of the extension ring between two adjacent side wall salient points.

7. The clamp ring of claim 1, wherein: the inner side of the extension ring is also provided with at least one extension part connected with the extension ring.

8. The clamp ring of claim 1, wherein: at least one positioning opening is arranged on the groove wall of the innermost annular groove close to the axis.

9. The clamp ring of claim 1, wherein: the edge of the groove wall of the annular groove is also provided with at least one grounding port.

10. A physical vapor deposition apparatus, characterized by: the physical vapor deposition equipment comprises the locking ring as claimed in any one of claims 1 to 9.