Plasma sputtering device

Abstract

The utility model discloses a plasma sputtering device which comprises a base, the side wall of the base is connected with an annular assembly, and the base and the annular assembly are used for placing wafers; a transition chamfer is arranged at the joint of the upper surface and the side wall of the base, and the included angle between the lower surface and the side wall of the base is an acute angle smaller than 45 degrees. The connection part of the upper surface and the side wall of the base is designed to be the round chamfer, so that charge accumulation can be reduced, the acute angle formed by the cross section between the lower surface and the side wall can increase charge accumulation, the position where charge accumulation is increased is far away from the edge of the wafer, the bombardment direction of argon ions is further changed, uniformity deviation is avoided, and the product yield is further improved.

Description

Technical Field

[0001] The utility model belongs to the field of semiconductor equipment, and particularly relates to a plasma sputtering device. Background Art

[0002] In the chemical vapor deposition (CVD) titanium nitride manufacturing process, a large amount of charge will accumulate at the edge of the base surface in the electrostatic equilibrium state, compared with the central region, as Figure 2 shown. Under the influence of the electric field, the bombarding particles show an inclined bombardment direction at the wafer edge and have a relatively large etching rate, which is likely to cause non-uniformity deviation, as Figure 1 shown. Summary of the Utility Model

[0003] The utility model provides a plasma sputtering device, in which the connection between the upper surface and the side wall of the base is designed as a round chamfer (to reduce charge accumulation), and the cross-section between the lower surface and the side wall forms an acute angle (to increase charge accumulation), so that the position where charge accumulation increases is far from the wafer edge, thereby changing the bombardment direction of argon ions, avoiding non-uniformity deviation, and further improving the product yield.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0005] A plasma sputtering device, comprising:

[0006] A base, a ring-shaped component is connected to the side wall of the base, and the base and the ring-shaped component are used for placing a wafer;

[0007] A transition chamfer is provided at the connection between the upper surface and the side wall of the base, and the included angle between the lower surface of the base and the side wall is an acute angle less than 45°.

[0008] The ring-shaped component surrounds the base, and the upper end of the ring-shaped component is higher than the upper surface of the wafer.

[0009] The base is a frustum of a cone with a radius of the lower surface larger than that of the upper surface.

[0010] The connection between the upper surface and the side wall of the base is a round chamfer transition.

[0011] The side surface of the base is embedded in the ring-shaped component, and the round chamfer transition area of the base is not embedded in the ring-shaped component.

[0012] The lower bottom of the base is embedded in the lower part of the ring-shaped component.

[0013] A slope surface is provided on one side of the ring-shaped component close to the base, and the included angle between the slope surface and the outer wall of the ring-shaped component is an acute angle less than 45°.

[0014] The starting position of the inclined plane is lower than the circular chamfer transition area of the base.

[0015] The base is a metal base, and the base is coaxial with the center of the ring assembly.

[0016] The beneficial effects of the present utility model are as follows:

[0017] The present utility model provides a plasma sputtering device. The connection between the upper surface and the side wall of the base is designed as a circular chamfer (to reduce charge accumulation), and the cross-section between the lower surface and the side wall forms an acute angle (to increase charge accumulation), so that the position where charge accumulation increases is far from the wafer edge, thereby changing the bombardment direction of argon ions, avoiding uniformity deviation, and further improving the product yield.

[0018] To make the above and other purposes, features and advantages of the present utility model more obvious and understandable, the following specifically enumerates preferred embodiments and, in conjunction with the accompanying drawings, makes a detailed description as follows. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the specific embodiments of the present utility model, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the following described drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a schematic structural diagram of a plasma sputtering device provided by the prior art.

[0021] Figure 2 It is a surface charge distribution diagram of the base provided by the prior art.

[0022] Figure 3 It is a schematic structural diagram of a plasma sputtering device provided by an embodiment of the present utility model Figure 1 。

[0023] Figure 4 It is a schematic structural diagram of a plasma sputtering device provided by an embodiment of the present utility model Figure 2 。 Detailed Embodiments

[0024] Regarding the foregoing and other technical contents, features and effects of the present utility model, they will be clearly presented in the following detailed description of a preferred embodiment in conjunction with the reference drawings. The directional terms mentioned in the following embodiments, such as: up, down, left, right, front or back, etc., are only references to the directions of the attached drawings. Therefore, the directional terms used are for illustration and not for limiting the present utility model.

[0025] Embodiment:

[0026] As Figure 3 shown, a schematic structure of a plasma sputtering device provided by an embodiment of the present invention is Figure 1 .

[0027] As Figure 4 shown, a schematic structure of a plasma sputtering device provided by an embodiment of the present invention is Figure 2 .

[0028] As Figure 3 shown, a plasma sputtering device includes:

[0029] A base 1, a ring-shaped component 2 is connected to the side wall of the base. The base 1 and the ring-shaped component 2 are used to place a wafer 4. The base 1 is a metal base, and the base 1 and the ring-shaped component 2 are coaxially centered.

[0030] The base 1 is a frustum of a cone with a radius of the lower surface greater than that of the upper surface. The ring-shaped component 2 surrounds the base 1, and the height of the ring-shaped component 2 is greater than the thickness of the wafer 4.

[0031] As Figure 3 shown, a plasma region 3 is provided above the base 1. The plasma region 3 is provided directly above the base 1 and has a certain distance from the base 1. The plasma region 3 generates bombarding particles. The generated bombarding particles are positively charged argon ions or other positively charged inert gas ions. The base 1 forms a negative bias voltage by connecting to a bias power supply to attract the bombarding particles.

[0032] As a preferred embodiment of the present invention, the argon gas in this embodiment belongs to an inert gas and basically does not chemically react with the sample. Therefore, we usually use argon ions as the ion source to bombard the sample.

[0033] As Figure 4 shown, a transition chamfer is provided at the connection between the upper surface and the side wall of the base 1. The cross-section between the lower surface and the side wall of the base 1 is triangular; the transition chamfer region a is a circular chamfer transition, and the included angle between the lower surface and the side wall of the base 1 is an acute angle b less than 45°.

[0034] According to Gauss's law, a conductor in electrostatic equilibrium is an equipotential body, the surface is an equipotential surface, the charge is distributed on the equipotential surface, and the surface charge density at each point on the equipotential surface is proportional to the magnitude of the electric field strength in the immediate vicinity of the local surface, that is, the magnitude of the gradient of the electric potential; and the greater the surface curvature (tip: large curvature, plane: small curvature, curvature ∝ 1 / radius), the greater the electric potential gradient and the greater the electric field strength. Therefore, a large amount of charge will accumulate at the edge of the surface of the base 1 compared to the central region.

[0035] The surface of the base 1 is distributed with charges. The circular chamfered area a at the connection between the upper surface and the side wall of the base 1 can reduce charge accumulation. The angle between the lower surface and the side wall of the base 1 is an acute angle b less than 45°. The design of the acute angle b can increase charge accumulation. The amount of charge in the circular chamfered area a at the upper edge of the base 1 is less than that at the position of the acute angle b at the lower edge of the base 1, so that the position where charge accumulation increases is far from the wafer edge, thereby changing the bombardment direction of argon ions, and the argon positive ions at the wafer edge no longer bombard in an inclined direction.

[0036] As Figure 4 shown, a ring-shaped component 2 is embedded in the side surface of the base 1, but the circular chamfered transition area a of the base 1 is not embedded in the ring-shaped component 2, and only the lower bottom of the base 1 is embedded in the lower part of the ring-shaped component 2; a ramp surface is provided on the side of the ring-shaped component 2 close to the base 1, and the angle between the ramp surface and the outer wall of the ring-shaped component 2 is an acute angle less than 45°, and the starting position of the ramp surface is lower than the circular chamfered transition area a of the base 1.

[0037] As a preferred embodiment of the present utility model, the ring-shaped component 2 in this embodiment can block the inclined force from the edge of the argon ion plasma (Ar Plasma) to prevent argon ions from hitting the wafer edge, resulting in abnormal uniformity. The titanium nitride process relies on the edge ring to evenly conduct gas to make the process thickness uniform.

[0038] The present utility model provides a plasma sputtering device. The connection between the upper surface and the side wall of the base is designed as a circular chamfer (to reduce charge accumulation), and the cross-section between the lower surface and the side wall forms an acute angle (to increase charge accumulation), so that the position where charge accumulation increases is far from the wafer edge, thereby changing the bombardment direction of argon ions, avoiding uniformity deviation, and further improving the product yield.

[0039] Finally, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of this utility model is usually placed during use. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present utility model. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0040] In addition, terms such as "horizontal", "vertical", "hanging", etc. do not mean that the components are required to be absolutely horizontal or hanging, but can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0041] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and defined, the terms "set", "installed", "connected", "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0042] Although this specification is described according to the implementation manners, not every implementation manner only contains an independent technical solution. This narrative manner of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each implementation manner can also be appropriately combined to form other implementation manners that can be understood by those skilled in the art.

[0043] The series of detailed descriptions listed above are only specific descriptions of the feasible implementation manners of the present utility model, and they are not used to limit the protection scope of the present utility model. Any equivalent implementation manners or changes made without departing from the technical spirit of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A plasma sputtering device, characterized in that: include: A base, a side wall of which is connected to a ring-shaped component, and the base and the ring-shaped component are used to place wafers; A transition chamfer is provided at the connection between the upper surface of the base and the side wall, and the angle between the lower surface of the base and the side wall is an acute angle less than 45°.

2. A plasma sputtering device according to claim 1, characterized in that: The annular component surrounds the base, and the upper end of the annular component is higher than the upper surface of the wafer.

3. A plasma sputtering device according to claim 1, characterized in that: The base is a truncated cone with a lower surface radius greater than an upper surface radius.

4. A plasma sputtering device according to claim 3, characterized in that: The connection between the upper surface of the base and the side wall is a rounded chamfer transition.

5. A plasma sputtering device according to claim 4, characterized in that: The side surface of the base is embedded in the annular component, and the round chamfer transition area of ​​the base is not embedded in the annular component.

6. A plasma sputtering device according to claim 5, characterized in that: The lower bottom of the base is embedded in the lower part of the annular component.

7. A plasma sputtering device according to claim 6, characterized in that: The annular component is provided with a slope surface on one side close to the base, and the angle between the slope surface and the outer wall of the annular component is an acute angle less than 45°.

8. A plasma sputtering device according to claim 7, characterized in that: The starting point of the slope surface is lower than the rounded chamfer transition area of ​​the base.

9. The plasma sputtering device according to claim 1, characterized in that: The base is a metal base, and the base is coaxial with the center of the annular component.

Images