Double-layer ion energy analyzer and negative ion energy analysis system and method

Abstract

The invention discloses a double-layer ion energy analyzer and a negative ion energy analysis system and method, and relates to the technical field of ion energy analys.The analyzer comprises a conductive shell made of a magnetic shielding material, the conductive shell is provided with a through groove, and the through groove is sequentially provided with a first-stage grid mesh, a second-stage grid mesh and a collector from the first end to the second end; positive high voltage is loaded on the first-stage grid mesh and the conductive shell, scanning voltage is loaded on the second-stage grid mesh, and positive high voltage is loaded on the collector; the analysis system comprises a high-voltage extraction electrode, an analyzer and a processing unit. According to the invention, the movement track of the negative ion beam under the electromagnetic field condition is simulated and calculated, the placement position of the analyzer is determined, the negative ion beam is led out into the analyzer by using the high-voltage leading-out pole and is converted into an electric signal, the ion energy analysis is completed under the condition that the magnetic field distribution in the ion source is not influenced, and the accurate measurement is ensured under the magnetic field condition.

Description

Technical Field

[0001] The present invention relates to the technical field of ion energy analysis, and in particular to a double-layer ion energy analyzer, a negative ion energy analysis system and a method. Background Art

[0002] Ion energy distribution is one of the basic parameters of ion beams and a basic diagnostic method for low-temperature plasma. Low-temperature plasma etching and deposition, as well as neutral beam heating in magnetic confinement nuclear fusion, all require ion beams with a certain energy and direction; ion beam coating technology is a method in which ions with a certain energy and density bombard the sample surface, thereby improving the optical, mechanical, and electrical properties of the film, achieving results that cannot be obtained by ordinary thermal evaporation processes; ion sources used in small medical cyclotrons and various accelerators all hope to obtain high-quality beams; therefore, analyzing the ion energy distribution of various ion sources is a crucial link.

[0003] The diagnostic technology of plasma can be divided into off-site technology and on-site technology. The off-site technology is to extract the plasma from the ion source and detect it in the external instrument. The disadvantage of this technology is the difficulty of ion extraction technology. There are many factors that make it difficult to measure or inaccurate. One of them is that the ion energy analyzers commonly used in commercial applications are only applicable to environments where only electric fields exist. Under conditions where both electromagnetic fields exist, accurate measurements cannot be made due to deflection. Summary of the invention

[0004] In order to solve the problem that the existing technical solutions cannot accurately measure the ion beam due to deflection under the condition of electromagnetic field, the present invention provides a double-layer ion energy analyzer, a negative ion energy analysis system and a method.

[0005] The present invention provides the following technical solution: a double-layer ion energy analyzer, comprising a conductive shell made of magnetic shielding material, the conductive shell being provided with a through slot, the through slot being provided with a first-level grid, a second-level grid and a collecting electrode in sequence from the first end to the second end, the conductive shell being further provided with a bottom plate at the second end, a first insulating layer being provided between the first-level grid and the second-level grid, a second insulating layer being provided between the second-level grid and the collecting electrode and the conductive shell, a third insulating layer being provided between the collecting electrode and the bottom plate and the conductive shell, the second insulating layer and the third insulating layer being both provided with through holes corresponding to the collecting electrode; the first-level grid and the conductive shell are both loaded with a positive high voltage, the second-level grid is loaded with a scanning voltage, and the collecting electrode is loaded with a positive high voltage.

[0006] Preferably, the scanning voltage potential is 0 to -200V.

[0007] Preferably, the bottom plate and the third insulating layer are both provided with threading holes.

[0008] A negative ion energy analysis system, comprising: A high-voltage extraction electrode, the high-voltage extraction electrode is loaded with a positive high voltage, and the central axis of the high-voltage extraction electrode is perpendicular to the ion emission surface of the ion source and aligned with the center of the ion emission surface; An analyzer, the analyzer being a double-layer ion energy analyzer, the analyzer being arranged on the side where the negative ion beam is deflected by the magnetic field; A processing unit, the collecting electrode of the analyzer is electrically connected to the processing unit.

[0009] A negative ion energy analysis method comprises the following steps: The motion trajectory of the negative ion beam under the electromagnetic field is simulated and calculated, and the analyzer is set on the side where the negative ion beam is deflected by the magnetic field, and the end surface of the first end of the through slot is perpendicular to the motion trajectory of the negative ion beam; The high voltage extraction electrode is loaded with a positive high voltage to extract the negative ion beam, and the negative ion beam is deflected toward the analyzer under the influence of the magnetic field; The conductive shell and the first-stage grid of the analyzer are loaded with positive high voltage to introduce the negative ion beam into the through slot, and the second-stage grid is loaded with scanning voltage. The ion beam with ion energy greater than the scanning voltage passes through the second-stage grid to reach the collecting electrode, is converted into an electrical signal and transmitted to the processing unit.

[0010] The beneficial effects of the present invention are as follows: the analyzer simplifies the structure of ion energy analysis, adopts magnetic shielding material as the conductive shell to shield complex magnetic field conditions, ensures that ion energy analysis is not affected by the magnetic field, and can guarantee accurate measurement both with and without magnetic field conditions; through simulation and calculation of the movement trajectory of the negative ion beam under electromagnetic field conditions, the placement position of the analyzer is determined, and the negative ion beam is led out into the analyzer by a high-voltage extraction electrode to be converted into an electrical signal, thereby completing the ion energy analysis without affecting the magnetic field distribution in the ion source. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 A schematic diagram of an embodiment of an analyzer.

[0012] Figure 2 The figure is a schematic diagram of the operation of an embodiment of a negative ion energy analysis system under magnetic field conditions.

[0013] Figure numerals: 10, analyzer; 11, conductive shell; 12, first-stage grid; 13, second-stage grid; 14, collecting electrode; 15, first insulating layer; 16, second insulating layer; 17, third insulating layer; 171, threading hole; 18, bottom plate; 20, high-voltage extraction electrode; 30, ion source; 40, movement trajectory of negative ion beam. DETAILED DESCRIPTION

[0014] The following is a more detailed description of the embodiments of the present invention in conjunction with the accompanying drawings and the accompanying drawings so that a person skilled in the art can implement the embodiments after reading the description. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Example

[0015] The present invention provides Figure 1 A double-layer ion energy analyzer shown includes a conductive shell 11, the conductive shell 11 is provided with a through slot as an installation space for other components and an introduction channel for ion beams. Specifically, the through slot is provided with a first-stage grid 12, a second-stage grid 13 and a collector 14 in sequence from the first end to the second end. The conductive shell 11 is also bolted with a bottom plate 18 at the second end. A first insulating layer 15 is provided between the first-stage grid 12 and the second-stage grid 13, a second insulating layer 16 is provided between the second-stage grid 13 and the collector 14 and the conductive shell 11, a third insulating layer 17 is provided between the collector 14 and the bottom plate 18 and the conductive shell 11, and the second insulating layer 16 and the third insulating layer 17 are both provided with through holes corresponding to the collector 14. The bottom plate 18 and the third insulating layer 17 are both provided with threading holes 171, and cables connecting the first-stage grid 12, the second-stage grid 13 and the collector 14 pass through the threading holes 171.

[0016] The conductive shell 11 is made of a magnetic shielding material with high magnetic permeability, such as iron, to achieve a magnetic shielding effect without affecting the magnetic field distribution of the ion source, and complete the ion energy distribution measurement. The first-level grid 12, the second-level grid 13 and the collector 14 can all refer to the relevant technology. The first-level grid 12 and the conductive shell 11 are electrically connected to the control circuit and loaded with a positive high voltage, and the negative ion beam drawn from the ion source is introduced into the analyzer. The ion source is grounded, and the second-level grid 13 is electrically connected to the control circuit and loaded with a scanning voltage. The scanning voltage potential is 0 to -200V, and the negative ion beam is screened: when the ion energy is less than the scanning voltage, the negative ion beam will be reflected, and when the ion energy is greater than the scanning voltage, the negative ion beam passes through the second-level grid 13 to reach the collector 14. The collector 14 is electrically connected to the control circuit and loaded with a positive high voltage to collect ions and form an electrical signal. The control circuit refers to the relevant technology.

[0017] Under non-magnetic field conditions, the central axis of the analyzer can be installed perpendicular to the ion emission surface and aligned in the center, and the first-stage grid 12 and the conductive shell 11 are loaded with a positive high voltage to introduce a negative ion beam into the analyzer. The ion beam with ion energy greater than the scanning voltage of the second-stage grid 13 passes through the second-stage grid 13 and is collected by the collector 14 to form an electrical signal. When used under non-magnetic field conditions, the conductive shell 11 can be made of a low magnetic permeability material. Example

[0018] The present invention provides Figure 2 A negative ion energy analysis system shown includes a high voltage extraction electrode 20, an analyzer 10 and a processing unit, and performs negative ion energy analysis under a magnetic field condition.

[0019] The central axis of the high-voltage extraction electrode 20 is perpendicular to the ion emission surface of the ion source 30 and aligned with the center of the ion emission surface. It is electrically connected to the control circuit and loaded with a positive high voltage to extract the negative ion beam from the ion source 30. Its structure can refer to related technologies.

[0020] The analyzer 10 is a double-layer ion energy analyzer as described in Example 1, and is arranged on the side where the negative ion beam is deflected by the magnetic field. The gyration radius generated by the negative ion beam under the influence of the magnetic field can be calculated according to the formula r=mv / qB, where r is the gyration radius, m is the ion mass, v is the ion velocity, q is the charge, and B is the magnetic induction intensity of the magnetic field. The negative ion beam motion trajectory 40 can be simulated in advance according to the above formula, so as to facilitate the analyzer 10 to be arranged at a suitable position.

[0021] The collector 14 of the analyzer 10 is electrically connected to the processing unit, and the processing unit can use a computer with data storage and computing functions to process the electrical signal formed by the collector 14. Specifically, the processing method includes: measuring the voltage-current curve of the collector, and then performing a differentiation to obtain the ion velocity distribution function, and the ion velocity distribution function (IVDF) is proportional to the ion energy distribution function (IEDF); the ion flux can be determined by the ion flow recorded by the collector. Example

[0022] The present invention provides a negative ion energy analysis method, based on a negative ion energy analysis system provided in Example 2, to complete negative ion energy analysis under magnetic field conditions.

[0023] The negative ion energy analysis method includes the following steps: The motion trajectory of the negative ion beam under the electromagnetic field is simulated and calculated, and the analyzer 10 is set on the side where the negative ion beam is deflected by the magnetic field, and the end surface of the first end of the through slot is perpendicular to the motion trajectory of the negative ion beam; The high voltage extraction electrode 20 is loaded with a positive high voltage to extract the negative ion beam from the ion source 30, and the negative ion beam is deflected toward the analyzer 10 under the influence of the magnetic field; The conductive shell 11 and the first-level grid 12 of the analyzer 10 are loaded with a positive high voltage to introduce the negative ion beam into the through slot, and the second-level grid 13 is loaded with a scanning voltage. The ion beam with ion energy greater than the scanning voltage passes through the second-level grid 13 to reach the collecting electrode 14, is converted into an electrical signal and transmitted to the processing unit for further processing.

[0024] The above are one or more embodiments of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A double-layer ion energy analyzer, characterized in that: It comprises a conductive shell made of magnetic shielding material, the conductive shell is provided with a through slot, the through slot is provided with a first-level grid, a second-level grid and a collecting electrode in sequence from the first end to the second end, the conductive shell is also provided with a bottom plate at the second end, a first insulating layer is provided between the first-level grid and the second-level grid, a second insulating layer is provided between the second-level grid and the collecting electrode and the conductive shell, a third insulating layer is provided between the collecting electrode and the bottom plate and the conductive shell, and the second insulating layer and the third insulating layer are both provided with through holes corresponding to the collecting electrode; the first-level grid and the conductive shell are both loaded with a positive high voltage, the second-level grid is loaded with a scanning voltage, and the collecting electrode is loaded with a positive high voltage.

2. A double-layer ion energy analyzer according to claim 1, characterized in that: The scanning voltage potential is 0 to -200V.

3. A double-layer ion energy analyzer according to claim 1, characterized in that: The bottom plate and the third insulating layer are both provided with threading holes.

4. A negative ion energy analysis system, characterized in that: include: A high-voltage extraction electrode, the high-voltage extraction electrode is loaded with a positive high voltage, and the central axis of the high-voltage extraction electrode is perpendicular to the ion emission surface of the ion source and aligned with the center of the ion emission surface; An analyzer, wherein the analyzer is a double-layer ion energy analyzer according to any one of claims 1 to 3, and the analyzer is arranged on the side where the negative ion beam is deflected by the magnetic field; A processing unit, the collecting electrode of the analyzer is electrically connected to the processing unit.

5. A negative ion energy analysis method, characterized in that: The following steps are involved: The motion trajectory of the negative ion beam under the electromagnetic field is simulated and calculated, and the analyzer is set on the side where the negative ion beam is deflected by the magnetic field, and the end surface of the first end of the through slot is perpendicular to the motion trajectory of the negative ion beam; The high voltage extraction electrode is loaded with a positive high voltage to extract the negative ion beam, and the negative ion beam is deflected toward the analyzer under the influence of the magnetic field; The conductive shell and the first-stage grid of the analyzer are loaded with positive high voltage to introduce the negative ion beam into the through slot, and the second-stage grid is loaded with scanning voltage. The ion beam with ion energy greater than the scanning voltage passes through the second-stage grid to reach the collecting electrode, is converted into an electrical signal and transmitted to the processing unit.

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