Lining plate and ion implanter

Abstract

The invention provides a lining plate and an ion implanter. The service life of the lining plate can be prolonged. The lining plate is used for blocking redundant ions in the ion implanter, and the shape of the lining plate is set to be adjusted into a central convex structure according to the distribution of ion beam diffraction so as to reduce the trapping dose of ion beams per unit area in a central area. According to the invention, the shape of the lining plate is set to be the same as that of ion beam diffraction in different regions, so that the ion beam trapping dose in a unit area in the central region can be reduced, and the influence of the problem on an implantation machine can be effectively reduced. The specific set shape can be reversely speculated according to the plane dose of the ion beam.

Description

Technical Field

[0001] The invention relates to the field of semiconductor equipment, and in particular to a liner and an ion implanter. Background Art

[0002] The ion implanter includes a focusing system. The focusing system is used to focus the accelerated ions into an ion beam with a diameter of several millimeters through a focusing cup. A graphite liner is usually installed on the focusing system. The graphite liner is usually installed near the path of the ion beam to block excess hydrogen ions and prevent these hydrogen ions from directly hitting the metal surface of the focusing system, thereby causing metal contamination.

[0003] When excess hydrogen ions directly bombard the graphite liner in the focusing system, the graphite liner will gradually become thinner due to the long-term beam bombardment. The thinning speed will vary with the size of the beam. After the graphite liner has been bombarded by the beam for a long time, the graphite liner will be broken through. At this time, the beam will bombard the metal surface of the focusing system, causing metal contamination of the entire beam line cavity.

[0004] Graphite liner is actually a common consumable for ion implanters, and for large beam ion implanters, the life of graphite is very short. The closer to the center, the more ion beams there are, which also leads to greater loss in the center of the graphite liner than at the edge. The existing graphite liner is square, 10mm thick, evenly distributed, has a service life of about 1 month, and serious loss in the center. How to increase the service life of the graphite liner is an urgent problem to be solved. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a liner and an ion implanter, which can increase the service life of the liner.

[0006] In order to solve the above problems, the present invention provides a liner for blocking excess ions in an ion implanter. The shape of the liner is set to be adjusted to a central convex structure according to the distribution of ion beam diffraction to reduce the capture dose of the ion beam per unit area in the central region.

[0007] Optionally, the liner is a shell structure with a parabolic cross-sectional shape.

[0008] Optionally, the lining plate is a solid plate structure with a spherical crown surface.

[0009] Optionally, the convex surface of the lining plate faces the ion source or faces away from the ion source. The thickness of the lining plate is greater than 10 mm.

[0010] Optionally, the material of the lining plate is graphite.

[0011] In order to solve the above problems, the present invention provides an ion implanter, including an ion source and an implantation target, wherein a lining plate is arranged between the ion source and the implantation target to block excess ions from bombarding the implantation target, and wherein the shape of the lining plate is arranged to adjust the capture cross-section of the ion beam dose in different regions to be the same according to the distribution of ion beam diffraction.

[0012] Optionally, the liner is a shell structure with a parabolic cross-sectional shape.

[0013] Optionally, the lining plate is a solid plate structure with a parabolic cross-sectional shape.

[0014] Optionally, the convex surface of the liner faces toward the ion source or faces away from the ion source.

[0015] The present invention sets the shape of the liner to be the same according to the distribution of ion beam diffraction, and adjusts the capture cross-section of the ion beam dose in different regions to be the same, thereby reducing the capture dose of the ion beam per unit area in the central region, and thus effectively reducing the impact of this problem on the implantation machine. The specific setting shape can be reversely inferred based on the planar dose of the ion beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Attached Figure 1 Shown is a schematic structural diagram of an ion implanter according to a specific embodiment of the present invention.

[0017] Attached Figure 2 Shown is a schematic structural diagram of an ion implanter according to a specific embodiment of the present invention.

[0018] Attached Figure 3 Shown is a schematic structural diagram of an ion implanter according to a specific embodiment of the present invention.

[0019] Attached Figure 4 Shown is a schematic structural diagram of an ion implanter according to a specific embodiment of the present invention. DETAILED DESCRIPTION

[0020] The specific implementation of the liner plate and ion implanter provided by the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Attached Figure 1The figure shows a schematic diagram of the structure of an ion implanter described in a specific embodiment of the present invention. The ion implanter includes an ion source 10 and an implantation target 11. A liner 12 is arranged between the ion source 10 and the implantation target 11. The liner 12 is used to block excess ions. In this specific embodiment, the shape of the liner 12 is set to be adjusted to have the same capture cross section for ion beam dose in different regions according to the distribution of ion beam diffraction. The material of the liner 12 is graphite, and the thickness is greater than 10 mm. The ion beam is a focused ion beam emitted outward from the ion source 10, which is focused within a range of several millimeters. If the liner 12 is set to be a plane, it is obvious that more doses of ion beams will be captured at the position in the central area, thereby accelerating the loss in the central area. If the shape of the liner 12 is set to a structure with a central protrusion, the capture dose of the ion beam per unit area in the central area can be reduced, and the impact of this problem on the implantation machine can be effectively reduced. The specific set shape can be reversely inferred based on the plane dose of the ion beam. For example, select a finite element area, calculate the dose of the area, and then multiply it by an angle to calculate a normalized captured dose value per unit area. Then, smooth the different finite elements to obtain a complete liner shape. Figure 1 As an optional specific implementation, the liner 12 can be designed as a shell with a parabolic cross-sectional shape to meet the above requirements.

[0022] As another specific implementation, see the attached Figure 2 The difference is that the attached Figure 1 The convex surface of the backing plate shown is oriented toward the ion source 10, while the Figure 2 The concave surface of the backing plate shown is facing the ion source 10. According to the design principle of setting the shape of the backing plate 12 to have the same capture cross section for ion beam dose in different regions, it is obvious that both designs can meet the requirements.

[0023] Attached Figure 3 The figure is a schematic diagram of the structure of an ion implanter according to a specific embodiment of the present invention. The ion implanter includes an ion source 10 and an implantation target 11. A liner 22 is arranged between the ion source 10 and the implantation target 11. The liner 22 is used to block excess ions. In this specific embodiment, the shape of the liner 12 is set to a centrally protruding structure to reduce the capture dose of the ion beam per unit area in the central region, which can effectively reduce the impact of this problem on the implantation machine. The setting method and principle refer to the description of the previous specific embodiment. In the attached Figure 3As an optional specific implementation, the liner 12 can be designed as a solid plate structure with a spherical crown surface to meet the above requirements. The center of the above shape has a small ion capture dose, and the center is thicker than the edge, which can withstand more doses of ions, thereby improving the overall service life.

[0024] As another specific implementation, see the attached Figure 4 The difference is that the attached Figure 3 The convex surface of the backing plate shown is oriented toward the ion source 10, while the Figure 4 The concave surface of the backing plate is shown facing the ion source 10. Figure 4 Although the capture capacity of the center is greater than that of the surrounding areas, since the thickness of the center is also greater than that of the surrounding areas, this design can obviously improve the overall service life.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A liner for blocking excess ions in an ion implanter, characterized in that: The shape of the backing plate is set to be adjusted to a central convex structure according to the distribution of ion beam diffraction, so as to reduce the capture dose of the ion beam per unit area in the central region.

2. The lining plate according to claim 1, characterized in that: The lining plate is a shell structure with a parabolic cross-sectional shape.

3. The lining plate according to claim 1, characterized in that: The lining plate is a solid plate structure with a spherical crown surface.

4. The lining plate according to claim 2 or 3, characterized in that: The convex surface of the backing plate faces toward the ion source or faces away from the ion source.

5. The lining plate according to claim 2, characterized in that: The thickness of the lining plate is greater than 10 mm.

6. The lining plate according to claim 1, characterized in that: The material of the lining plate is graphite.

7. An ion implanter, comprising an ion source and an implantation target, wherein a liner is arranged between the ion source and the implantation target to prevent excess ions from bombarding the implantation target, wherein: The shape of the backing plate is set to adjust the capture cross sections of the ion beam dose in different areas to be the same according to the distribution of ion beam diffraction.

8. The ion implanter according to claim 7, characterized in that: The lining plate is a shell structure with a parabolic cross-sectional shape.

9. The ion implanter according to claim 7, characterized in that: The lining plate is a solid plate structure with a parabolic cross-sectional shape.

10. The ion implanter according to claim 8 or 9, characterized in that: The convex surface of the backing plate faces toward the ion source or faces away from the ion source.

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