Ion implanter and ion implantation method

Abstract

Provided are an ion implanter and an ion implantation method. The ion implanter comprises: a target disc (20), which comprises a plurality of wafer placement positions (201) arranged circumferentially, wherein the target disc (20) rotates at a speed of less than 200 revolutions per minute; and an implantation ion source (21), which faces the target disc (20), and performs, in the radial direction of the target disc (20), scan-type ion implantation on the surfaces of wafers placed at the wafer placement positions (201), wherein the scanning frequency is above 500 Hz. It is no longer necessary for the target disc (20) to implement mechanical scanning in a manner of moving up and down in a direction perpendicular to an ion implantation direction, thereby greatly simplifying a motion mechanism of a large disc and reducing the processing difficulty. The scanning frequency is set to a high frequency above 500 Hz, and the target disc (20) rotates at a speed of less than 200 revolutions per minute, and thus the uniformity of implantation can still meet process requirements. Moreover, a dose loss due to overscanning is avoided, and the implantation efficiency of the ion implanter is increased more than twofold.

Description

Ion implanter and ion implantation method

[0001] Related application citations

[0002] This application claims priority to Chinese patent application No. 202311630169.0, filed on November 30, 2023, entitled “ION IMPLANTATION MACHINE AND ION IMPLANTATION METHOD,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of semiconductor equipment, and in particular to an ion implanter and an ion implantation method. Background Art

[0004] In the technical route of forming SOI by hydrogen ion implantation and stripping, the hydrogen ion implanter is the most critical machine. In the prior art, hydrogen ion implanters all use an implantation method that combines electrical scanning with mechanical scanning. FIG1A shows a schematic structural diagram of an ion implanter in the prior art, including a target disk 10 and an implantation ion source 11. The target disk 10 includes multiple wafer placement positions 101 arranged along a circumference. The implantation ion source 11 is positioned toward the target disk 10 to accelerate the implantation ions into the wafer surface. FIG1B is a schematic diagram of the scan path after magnification of a single scan position. Scan path 12 is the path that the implanted ions sweep across the target disk 10. In order to implant all areas, the target disk 10 needs to move up and down in a direction perpendicular to the ion implantation direction, and the scanning frequency can only be 20-30 Hz. In addition, to ensure implantation uniformity, the target disk 10 needs to rotate at a high speed of more than 1000 rpm. Obviously, the disadvantages of the above design are its complex structure and low implantation efficiency.

[0005] Summary of the Invention

[0006] The technical problem to be solved by the present application is to provide an ion implanter and an ion implantation method with a simple structure and high implantation efficiency.

[0007] In order to solve the above problems, the present application provides an ion implanter, comprising: a target disk, comprising a plurality of wafer placement positions arranged along a circumference, the target disk rotating at a speed of less than 200 revolutions per minute; an injection ion source, facing the target disk, performing scanning ion implantation on the surface of a wafer placed at the wafer placement positions along the radial direction of the target disk, with a scanning frequency greater than 500 Hz.

[0008] Optionally, the scanning frequency is 500-1000 Hz.

[0009] Optionally, the rotation speed of the target plate is 30-200 rpm.

[0010] Optionally, the energy of the implanted ions is 100 KeV to 200 KeV.

[0011] Optionally, in the scanning ion implantation along the radial direction of the target disk, the scanning frequency of the implantation ion source in a single cycle is inversely proportional to the distance from the rotation center of the target disk.

[0012] In order to solve the above problems, the present application also provides an ion implantation method, comprising: placing a wafer to be implanted on a target disk, the target disk comprising a plurality of wafer placement positions arranged along a circumference, and the target disk rotating at a speed of less than 200 revolutions per minute; performing scanning ion implantation on the wafer on the target disk along the radial direction of the target disk, with a scanning frequency greater than 500 Hz.

[0013] Optionally, the scanning frequency is 500-1000 Hz.

[0014] Optionally, the rotation speed of the target plate is 30-200 rpm.

[0015] Optionally, the energy of the implanted ions is 100 KeV to 200 KeV.

[0016] Optionally, in the radial direction of the target disk, scanning ion implantation is performed, and the scanning frequency of the implantation ion source in a single cycle is inversely proportional to the distance from the rotation center of the target disk.

[0017] The target disk in this application no longer needs to be mechanically scanned by moving it up and down perpendicular to the ion implantation direction, significantly simplifying the target disk's motion mechanism and processing complexity. The scanning frequency is set to a high-frequency scan greater than 500 Hz, and the target disk rotates at a speed of less than 200 rpm. Implant uniformity still meets process requirements. Furthermore, dose loss due to overscanning is avoided, more than doubling the implantation efficiency of the ion implanter. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1A is a schematic structural diagram of an ion implanter in the prior art.

[0019] FIG1B is a schematic diagram of the scanning path of a single scanning position in the structure shown in FIG1A after being magnified.

[0020] FIG2 is a schematic structural diagram of an ion implanter according to a specific embodiment of the present application.

[0021] FIG3 is a schematic diagram of the scanning path after enlarging a single scanning position in the structure shown in FIG2.

[0022] FIG4 is a schematic diagram showing the steps of the ion implantation method according to a specific embodiment of the present application. DETAILED DESCRIPTION

[0023] The specific implementation methods of the ion implanter and ion implantation method provided in this application are described in detail below with reference to the accompanying drawings.

[0024] FIG2 is a schematic structural diagram of the ion implanter according to a specific embodiment of the present application, comprising: a target disk 20, and an implantation ion source 21. The target disk 20 comprises a plurality of wafer placement positions 201 arranged along a circumference, and the target disk rotates at a speed of less than 200 rpm. The implantation ion source 21 is disposed toward the target disk 20 to accelerate the implantation ions into the wafer surface. In this specific embodiment, the implantation ion source 21 performs scanning ion implantation on the wafer surface positioned at the wafer placement position 201 along the radial direction of the target disk 20, with a scanning frequency greater than 500 Hz. More preferably, the scanning frequency is set to 500-1000 Hz. The rotation speed of the target disk is set to 30-200 rpm, and the energy of the implanted ions is 100 KeV to 200 KeV.

[0025] In some embodiments, in the scanning ion implantation along the radial direction of the target disk 20 , the scanning frequency of the implantation ion source 21 in a single cycle is inversely proportional to the distance from the rotation center of the target disk 20 .

[0026] FIG3 is a schematic diagram of the scanning path after enlarging a single scanning position in the above-mentioned specific embodiment. Scanning path 30 is the path that the implanted ions sweep across the target disk 20. The direction of the arrow is the scanning direction, which is from the outside to the inside along the radial direction of the target disk 20. In other specific embodiments, it can also be from the inside to the outside or reciprocating scanning. The scanning path 30 is slightly larger than the diameter of the wafer to ensure that the entire area of ​​the wafer can be implanted. Obviously, with this scanning path, the target disk 20 no longer needs to move up and down in a direction perpendicular to the ion implantation to perform mechanical scanning, which greatly simplifies the target disk's motion mechanism and processing difficulty. In an ion implanter that eliminates mechanical scanning, since the relative position of the target disk 20 and the implantation ion source 21 in the vertical direction remains unchanged, the scanning frequency can be set to a high-frequency scanning greater than 500 Hz, and the target disk rotates at a speed of less than 200 rpm, and the implantation uniformity can still meet the process requirements. Furthermore, due to the use of mechanical scanning, the instability of the mechanical mechanism necessitates a large number of overscan settings during the implantation process to ensure implant uniformity. The aforementioned ion implanter utilizes only electronic scanning technology, which significantly avoids dose loss from overscanning. Compared to implants with the same beam current, more ions can be implanted into the wafer rather than at the edge. In practice, the implantation efficiency of this ion implanter has more than doubled.

[0027] FIG4 is a schematic diagram of the steps of the ion implantation method according to a specific embodiment of the present application. Ion implantation is performed using the above-mentioned ion implanter, and the steps implemented include: step S10, placing the wafer to be implanted on a target disk, wherein the target disk includes a plurality of wafer placement positions arranged along a circumference, and the target disk rotates at a speed of less than 200 rpm; and step S11, performing scanning ion implantation on the wafer on the target disk along the radial direction of the target disk, with a scanning frequency greater than 500 Hz.

[0028] For the explanation and limitation of the above steps, please refer to the corresponding content in the previous specific implementation.

[0029] The above is only a preferred embodiment of the present application. It should be pointed out that ordinary technicians in this technical field can make several improvements and modifications without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. An ion implanter, wherein: include: A target plate, comprising a plurality of wafer placement positions arranged along a circumference, wherein the target plate rotates at a speed less than 200 revolutions per minute; An implantation ion source faces the target disk and performs scanning ion implantation on the surface of the wafer placed at the wafer placement position along the radial direction of the target disk, with a scanning frequency greater than 500 Hz.

2. The ion implanter according to claim 1, wherein: The scanning frequency is 500-1000 Hz.

3. The ion implanter according to claim 1, wherein: The rotation speed of the target plate is 30-200 rpm.

4. The ion implanter according to claim 1, wherein: The energy of the implanted ions is 100 KeV to 200 KeV.

5. The ion implanter according to claim 1, wherein: In the scanning ion implantation along the radial direction of the target disk, the scanning frequency of the implantation ion source in a single cycle is inversely proportional to the distance from the rotation center of the target disk.

6. An ion implantation method, wherein: include: Placing the wafer to be implanted on a target plate, wherein the target plate comprises a plurality of wafer placement positions arranged along a circumference, and the target plate rotates at a speed less than 200 revolutions per minute; Scanning ion implantation is performed on the wafer on the target disk along the radial direction of the target disk, with a scanning frequency greater than 500 Hz.

7. The ion implantation method according to claim 6, wherein: The scanning frequency is 500-1000 Hz.

8. The ion implantation method according to claim 6, wherein: The rotation speed of the target plate is 30-200 rpm.

9. The ion implantation method according to claim 6, wherein: The energy of the implanted ions is 100 KeV to 200 KeV.

10. The ion implantation method according to claim 6, wherein: In the scanning ion implantation along the radial direction of the target disk, the scanning frequency of the implantation ion source in a single cycle is inversely proportional to the distance from the rotation center of the target disk.

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