Emitter structure for enhanced ion current

Abstract

The present invention discloses an emitter structure for enhancing ion current, comprising a needle tip and a needle handle. The needle tip is formed at the front end of the emitter structure for enhancing ion current, and has a needle tip point, a first diameter and a curvature radius. The needle handle is formed behind the needle tip at the front end of the emitter structure for enhancing ion current, wherein the length of the needle handle together with the needle tip is calculated from the needle tip point of the needle tip to the first end point of the needle handle, the first distance from the needle tip to the first end point is 300 times the first diameter, the curvature radius of the needle tip is between 50 nanometers and 5 micrometers, and the first diameter is 2 times the curvature radius.

Description

Technical Field

[0001] The present invention relates to an emitter structure, and in particular to an emitter structure capable of enhancing ion current. Background Art

[0002] Gas field ions are generated by the ionization of gas atoms or molecules in the electric field above the emitter surface. Gas atoms and molecules are originally electrically neutral. When gas atoms and molecules approach the needle-shaped emitter, they are affected by the electric field on the emitter surface and are polarized and then captured due to heat exchange. Finally, gas atoms and molecules are attracted to the emitter needle tip due to the polarization potential well. Afterwards, the gas atoms or molecules attracted to the emitter needle tip will be ionized by the electric field above the needle tip to become gas field ions. In other words, as the effective gas capture area increases, the ion current increases. Therefore, the structure of the emitter will affect the amount of gas field ions gathered.

[0003] See also FIG. 5A to FIG. 5D , Figure 5A is a schematic diagram of a general emitter structure 1, Figure 5B for Figure 5A A partial enlarged schematic diagram of a general emitter structure. Figure 5C and Figure 5D It is a partial enlarged schematic diagram of the needle handle 12 at different angles θ. Figure 5E Schematic diagram of the ion current generated by the handle portion 12 at different angles θ under the working pressure of helium, wherein the angle θ is the angle formed by the oblique line formed by the turning point of the curvature radius R and the position corresponding to the diameter of the handle portion 12, and the horizontal extension line of the tip portion 11 at the turning point of the curvature radius R. It can be seen from the above figure that when the angle θ of the handle portion 12 of the emitter structure 1 is smaller, the more the ion current increases.

[0004] According to the above results, since the increase of ion current is related to the emitter structure, how to design an emitter structure that enhances the ion current has become a technical issue that urgently needs to be studied. Summary of the invention

[0005] In view of the above technical problems, the present invention discloses an emitter structure for enhancing ion current, comprising a needle tip and a needle handle. The needle tip is formed at the front end of the emitter structure for enhancing ion current, and has a needle tip point, a first diameter and a radius of curvature. The needle handle is formed behind the needle tip at the front end of the emitter structure for enhancing ion current, wherein the length of the needle handle together with the needle tip is calculated from the needle tip point of the needle tip to the first end point of the needle handle, and the first distance from the needle tip to the first end point is 300 times the first diameter, wherein the radius of curvature of the needle tip is between 50 nanometers and 5 micrometers, and the first diameter is 2 times the radius of curvature. Accordingly, the emitter structure for enhancing ion current according to the present invention can increase the ion current it generates.

[0006] As described above, the emitter structure for enhancing ion current of the present invention has the characteristics of a large curvature radius at the needle tip, and a longer length and a flat angle at the needle handle. Accordingly, the ion current generated by the emitter structure for enhancing ion current of the present invention can be significantly increased from the picoampere level to the nanoampere level. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1A Schematic diagram of the curvature radius of the needle tip and the effective gas capture area;

[0008] Figure 1B A schematic diagram of the angle formed by the second diameter of the needle handle and the effective gas capture area;

[0009] Figure 2 A schematic diagram of an emitter structure for enhancing ion current as part of the present invention;

[0010] Figure 3 Another schematic diagram of an emitter structure for enhancing ion current as part of the present invention;

[0011] Figure 4 Another schematic diagram of an emitter structure for enhancing ion current as part of the present invention;

[0012] Figure 5A is a schematic diagram of a general emitter structure;

[0013] Figure 5B for Figure 5A A partial enlarged schematic diagram of a general emitter structure;

[0014] Figure 5C and Figure 5D is a partial enlarged schematic diagram of the needle handle at different angles; and

[0015] Figure 5E This is a schematic diagram of the ion current generated at different angles of the needle handle under helium working pressure. DETAILED DESCRIPTION

[0016] See also Figure 1A , Figure 1A The figure is a schematic diagram of the curvature radius of the needle tip and the effective gas capture area. Figure 1A As shown in FIG. 1 , when the radius of curvature of the needle tip is larger, the effective gas capture area is larger, so that the ion current is enhanced.

[0017] See also Figure 1B , Figure 1B This is a schematic diagram of the angle formed by the needle handle diameter and the effective gas capture area. Figure 1B As shown in the figure, the smaller the angle, the greater the ion current generated. The angle is the angle between the oblique line formed by the turning point of the curvature radius and the corresponding position of the needle handle diameter, and the horizontal extension line of the needle tip at the turning point of the curvature radius. Figure 1A and Figure 1B According to the teachings of , the emitter structure designed by the present invention to enhance the ion current is as follows.

[0018] See also Figure 2 , Figure 2 The schematic diagram of the emitter structure for enhancing ion current of a part of the present invention. The emitter structure 2 for enhancing ion current includes a needle tip 21 and a needle handle 22. The needle tip 21 is formed at the front end of the emitter structure 2 for enhancing ion current, and has a needle tip point P0, a first diameter D1 and a curvature radius R. The needle handle 22 is formed behind the needle tip 21 at the front end of the emitter structure 2 for enhancing ion current, wherein the length L of the needle handle 22 together with the needle tip 21 is calculated from the needle tip point P0 of the needle tip 21 to the first end point position P1 of the needle handle 22, and the first distance L from the needle tip point P0 to the first end point position P1 is 300 times the length of the first diameter D1, wherein the curvature radius R of the needle tip 21 is between 50 nanometers and 5 micrometers, and the first diameter D1 is between 100 nanometers and 10 micrometers. The first diameter D1 is twice the size of the curvature radius R. The emitter structure for enhancing ion current thus completed can increase the generated ion current.

[0019] As described above, since the magnitude of the ion current generated by the emitter structure 2 for enhancing the ion current is related to the angle, the smaller the angle, the greater the ion current generated. The angle is in a corresponding relationship with the diameter on the needle handle 22. In fact, in the process of manufacturing the emitter structure 2 for enhancing the ion current, it is not possible to extend the length of the needle handle 22 indefinitely and produce a corresponding uniform diameter so that it has a smaller angle. In other words, in the process of forming the emitter structure 2 for enhancing the ion current, on the needle handle 22, the diameter formed in each length interval is not a constant value (constant), that is, the diameter corresponding to the needle handle 22 in each length interval is not a uniform diameter (uniform). However, according to the above Figure 1B According to the teaching of , in the emitter structure 2 for enhancing ion current, as long as a smaller angle is formed in a length interval of the needle handle 22, that is, a smaller diameter is formed, the ion current generated by the emitter structure 2 for enhancing ion current can be increased. Therefore, in the following embodiments, the relationship between a plurality of node positions and end point positions and the corresponding diameter size in each length interval of the needle handle 22 is listed respectively.

[0020] See also Figure 3 , Figure 3 Another schematic diagram of an emitter structure for enhancing ion current as part of the present invention. In this embodiment, there is at least one first node position between the second end position P2 and the third end position P3 on the needle handle 22, and the second diameter D2 corresponding to the node position is less than 1.2 times the first diameter D1. The second distance from the needle tip point P0 to the second end position P2 is 3 times the first diameter D1, and the third distance from the needle tip point P0 to the third end position P3 is 60 times the first diameter D1. Furthermore, between the needle tip point P0 and the second end position P2, the third diameter D3 of the needle handle 22 is less than 1.2 times the first diameter D1.

[0021] See also Figure 4 , Figure 4 Another schematic diagram of an emitter structure for enhancing ion current of a part of the present invention. In this embodiment, there is at least one second node position between the fourth end position P4 and the first end position P1 on the needle handle 22, and the corresponding fourth diameter D4 is less than 2 times the first diameter D1. The fourth distance from the needle tip point P0 to the fourth end position P4 is 18 times the first diameter D1. Furthermore, between the needle tip point P0 and the fourth end position P4, the fifth diameter D5 of the needle handle 22 is less than 2 times the first diameter D1.

[0022] Please refer to Table 1 below, which shows the simulation and experimental results of the emitter structure at different angles formed by the second diameter of the needle handle. As described above, the emitter structure 2 for enhancing ion current of the present invention has three technical features, including a large radius of curvature R at the needle tip 21, a longer length and a flat angle at the needle handle 22. The simulation and experimental results confirm that the smaller the angle of the needle handle 22 of the emitter structure 2, the more effective gas capture area, and the greater the increase in ion current. In addition, it should be noted that in Table 1, the influence of the radius of curvature R of the needle tip 21 due to the measurement tolerance is negligible. Furthermore, according to the simulation and experimental results, it is confirmed that the ion current generated by the emitter structure 2 for enhancing ion current of the present invention is increased by about 5 times.

[0023] Table 1

[0024]

[0025] In summary, the emitter structure for enhancing ion current of the present invention has the characteristics of a large curvature radius at the needle tip, and a longer length and a flat angle at the needle handle. Accordingly, the ion current generated by the emitter structure for enhancing ion current of the present invention can be significantly increased from the picoampere level to the nanoampere level.

Claims

1. An emitter structure for enhancing ion current, comprising: A needle tip portion, formed at a front end of the emitter structure for enhancing ion current, having a needle tip point, a first diameter and a radius of curvature; and A needle handle portion formed behind the needle tip portion of the front end of the emitter structure for enhancing ion current; The length of the needle handle and the needle tip is calculated from the needle tip to a first end point of the needle handle, and a first distance from the needle tip to the first end point is 300 times the first diameter. The radius of curvature of the needle tip is between 50 nanometers and 5 micrometers; The first diameter is twice the radius of curvature; There is at least one first node between a second end position and a third end position on the needle handle, and a second diameter corresponding to the position of the at least one first node is smaller than 1.2 times the first diameter; A second distance from the needle tip to the second end position is 3 times the first diameter, and a third distance from the needle tip to the third end position is 60 times the first diameter.

2. The emitter structure for enhancing ion current as claimed in claim 1, wherein between the needle tip and the second end position, a third diameter of the needle handle is less than 1.2 times the first diameter.

3. An emitter structure for enhancing ion current, comprising: A needle tip portion, formed at a front end of the emitter structure for enhancing ion current, having a needle tip point, a first diameter and a radius of curvature; and A needle handle portion formed behind the needle tip portion of the front end of the emitter structure for enhancing ion current; The length of the needle handle and the needle tip is calculated from the needle tip to a first end point of the needle handle, and a first distance from the needle tip to the first end point is 300 times the first diameter. The radius of curvature of the needle tip is between 50 nanometers and 5 micrometers; The first diameter is twice the radius of curvature; There is at least one second node between a fourth end point on the needle handle and the first end point, and a fourth diameter corresponding to the position of the at least one second node is less than 2 times the first diameter; A fourth distance from the needle tip to the fourth end point is 18 times the first diameter. 4 . The emitter structure for enhancing ion current as claimed in claim 3 , wherein between the needle tip and the fourth end position, a fifth diameter of the needle handle is less than 2 times the first diameter.

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